RTT OWD Metrics Integration

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تمت الإجابة باستخدام OpenAI 01 Mini بواسطة OpenAI01

سؤال

class VideoInitiatorFragment : Fragment() {

// Class member variables remain unchanged
private lateinit var socket: Socket
private var localPeer: PeerConnection? = null
private var localView: SurfaceViewRenderer? = null
private var localEglBase: EglBase? = null
private val pendingIceCandidates = mutableListOf<IceCandidate>()
private var currentRoom: String? = null
private lateinit var signalingServerUrl: String
private lateinit var stunUrl: String
private lateinit var turnUrl: String
private lateinit var turnUsername: String
private lateinit var turnPassword: String

private val TAG: String = "WebRTC-Initiator"

// State variables for RTT and OWD
private val rttState = mutableLongStateOf(0L)
private val owdState = mutableLongStateOf(0L)
private val rttHistory = mutableStateListOf<Long>()
private val owdHistory = mutableStateListOf<Long>()

private var statsJob: Job? = null

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)

// Retrieve data from arguments
currentRoom = arguments?.getString("room") ?: "default-room"
signalingServerUrl = arguments?.getString("signalingServerUrl") ?: "https://wstszx.us.kg"
stunUrl = arguments?.getString("stunUrl") ?: "stun:stun.wstszx.us.kg:3478"
turnUrl = arguments?.getString("turnUrl") ?: "turn:turn.wstszx.us.kg:5349"
turnUsername = arguments?.getString("turnUsername") ?: "wstszx"
turnPassword = arguments?.getString("turnPassword") ?: "930379"

Log.d(
TAG,
"onCreate: Role = Initiator, Room = $currentRoom, Signaling Server = $signalingServerUrl, STUN URL = $stunUrl, TURN URL = $turnUrl"
)
}

private val requestPermissionsLauncher =
registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
permissions.entries.forEach { (permission, isGranted) ->
if (isGranted) {
Toast.makeText(requireContext(), "$permission 权限已授予", Toast.LENGTH_SHORT).show()
} else {
Toast.makeText(requireContext(), "$permission 权限被拒绝", Toast.LENGTH_SHORT).show()
}
}
onPermissionsChecked()
}

override fun onCreateView(
inflater: android.view.LayoutInflater,
container: android.view.ViewGroup?,
savedInstanceState: Bundle?
): android.view.View {
return ComposeView(requireContext()).apply {
setContent {
WebRTCComposeLayout()
}
}
}

@Composable
fun WebRTCComposeLayout() {
val context = LocalContext.current
lateinit var peerConnectionFactory: PeerConnectionFactory
var localVideoTrack: VideoTrack? by remember { mutableStateOf(null) }

Surface(color = Color.Black) {
Column(modifier = Modifier.fillMaxSize()) {

Spacer(modifier = Modifier.height(8.dp))

// Display RTT and OWD
Column(modifier = Modifier.padding(horizontal = 16.dp)) {
Text(
text = "往返时延 (RTT): ${rttState.longValue} ms",
color = Color.White,
style = MaterialTheme.typography.bodyMedium,
modifier = Modifier.padding(bottom = 4.dp)
)
Text(
text = "单向时延 (OWD): ${owdState.longValue} ms",
color = Color.White,
style = MaterialTheme.typography.bodyMedium,
modifier = Modifier.padding(bottom = 8.dp)
)
}

// Additional UI components can go here...

}

LaunchedEffect(Unit) {
val options = PeerConnectionFactory.InitializationOptions.builder(context)
.createInitializationOptions()
PeerConnectionFactory.initialize(options)

val encoderFactory = DefaultVideoEncoderFactory(
localEglBase!!.eglBaseContext, true, true
)

val decoderFactory = DefaultVideoDecoderFactory(localEglBase!!.eglBaseContext)

peerConnectionFactory = PeerConnectionFactory.builder()
.setVideoEncoderFactory(encoderFactory)
.setVideoDecoderFactory(decoderFactory)
.createPeerConnectionFactory()

initLocalVideo(context, localView, peerConnectionFactory, localEglBase!!) {
localVideoTrack = it
}

createPeerConnection(
context,
peerConnectionFactory,
localVideoTrack
) {
localPeer = it
startStatsCollection() // Start collecting statistics
}

initializeSocketIO()

requestPermissionsIfNeeded()
startTimeSync()
}
}
}

private fun startTimeSync(intervalMs: Long = 5000L) {
viewLifecycleOwner.lifecycleScope.launch {
while (isActive) {
delay(intervalMs) // Sync every 5 seconds
requestTimeSync()
}
}
}

private fun startStatsCollection() {
statsJob = viewLifecycleOwner.lifecycleScope.launch {
while (isActive) {
delay(1000) // Collect stats every second
localPeer?.getStats { report ->
parseStatsReport(report)
} ?: Log.e(TAG, "Failed to get stats: localPeer is null.")
}
}
}

private fun parseStatsReport(report: RTCStatsReport) {
}

private fun initializeSocketIO() {
val protocol = if (signalingServerUrl.startsWith("https")) "https" else "http"
val socketUrl = signalingServerUrl

val options = IO.Options().apply {
transports = arrayOf("websocket")
secure = protocol == "https"
path = "/socket.io/"
}

try {
socket = IO.socket(socketUrl, options)

socket.on(Socket.EVENT_CONNECT) {
Log.d(TAG, "Socket connected")
socket.emit("join", currentRoom)
Log.d(TAG, "Joined room: $currentRoom")
}

socket.on(Socket.EVENT_CONNECT_ERROR) { args ->
if (args.isNotEmpty()) {
val error = args[0]
Log.e(TAG, "Socket connection error: $error")
}
}

socket.on(Socket.EVENT_DISCONNECT) { args ->
if (args.isNotEmpty()) {
val reason = args[0]
Log.d(TAG, "Socket disconnected: $reason")
}
}

socket.on("signal") { args ->
Log.d(TAG, "Received signaling: ${args[0]}")
if (args.isNotEmpty() && args[0] is JSONObject) {
val data = args[0] as JSONObject
handleSignalingData(data)
}
}

socket.connect()
Log.d(TAG, "Connecting to Socket: $socketUrl...")
} catch (e: Exception) {
Log.e(TAG, "Error connecting to Socket: ${e.message}")
}
}

private fun requestPermissionsIfNeeded() {
}

private fun onPermissionsChecked() {
Toast.makeText(requireContext(), "所有必要权限已被授予", Toast.LENGTH_SHORT).show()
}

private fun initLocalVideo(
context: Context,
localView: SurfaceViewRenderer?,
peerConnectionFactory: PeerConnectionFactory,
eglBase: EglBase,
onLocalVideoTrack: (VideoTrack) -> Unit
) {
}

private fun createCameraCapturer(context: Context): CameraVideoCapturer {
}

private fun createPeerConnection(
context: Context,
peerConnectionFactory: PeerConnectionFactory,
localVideoTrack: VideoTrack?,
onLocalPeerCreated: (PeerConnection) -> Unit
) {
}

private fun createAnswer(peerConnection: PeerConnection, onAnswerCreated: (String) -> Unit) {
Log.d(TAG, "Creating answer...")
}

private fun handleSignalingData(data: JSONObject) {
Log.d(TAG, "Handling signaling data: $data")
when (data.getString("type")) {
"offer" -> {
Log.d(TAG, "Received offer")
val sdp = SessionDescription(
SessionDescription.Type.OFFER,
data.getJSONObject("sdp").getString("sdp")
)
localPeer?.setRemoteDescription(object : SdpObserver {
override fun onSetSuccess() {
Log.d(TAG, "Set remote description (offer) success")
createAnswer(localPeer!!) { answer ->
val signalData = JSONObject().apply {
put("type", "answer")
put("sdp", JSONObject().put("sdp", answer))
put("room", currentRoom)
}

socket.emit("signal", signalData)

pendingIceCandidates.forEach { candidate ->
localPeer?.addIceCandidate(candidate)
}
pendingIceCandidates.clear()
}
}

override fun onSetFailure(error: String?) {
Log.e(TAG, "Set remote description (offer) error: $error")
}

override fun onCreateSuccess(p0: SessionDescription?) {}
override fun onCreateFailure(p0: String?) {}
}, sdp)
}

"answer" -> {
Log.d(TAG, "Received answer")
val sdp = SessionDescription(
SessionDescription.Type.ANSWER,
data.getJSONObject("sdp").getString("sdp")
)
localPeer?.setRemoteDescription(object : SdpObserver {
override fun onSetSuccess() {
pendingIceCandidates.forEach { candidate ->
localPeer?.addIceCandidate(candidate)
}
pendingIceCandidates.clear()
Log.d(TAG, "Set remote description (answer) success")
}

override fun onSetFailure(error: String?) {
Log.e(TAG, "Set remote description error: $error")
}

override fun onCreateSuccess(p0: SessionDescription?) {}
override fun onCreateFailure(p0: String?) {}
}, sdp)
}

"ice" -> {
Log.d(TAG, "Received ICE candidate")
val candidateData = data.getJSONObject("candidate")
val candidate = IceCandidate(
candidateData.getString("sdpMid"),
candidateData.getInt("sdpMLineIndex"),
candidateData.getString("candidate")
)

if (localPeer?.remoteDescription != null) {
localPeer?.addIceCandidate(candidate)
} else {
pendingIceCandidates.add(candidate)
}
}

"time_sync_response" -> {
Log.d(TAG, "Received time_sync_response")
val t1 = data.getLong("t1")
val t2 = data.getLong("t2")
val t3 = data.getLong("t3")
val t4 = System.currentTimeMillis()

// Calculate RTT and OWD
val rtt = t4 - t1 - (t3 - t2)
val owd = t2 - t1 // One-Way Delay from Initiator to Receiver

Log.d(TAG, "Time Sync: RTT=$rtt ms, OWD=$owd ms")

viewLifecycleOwner.lifecycleScope.launch {
// Update RTT state
rttState.longValue = rtt

// Update RTT history
rttHistory.add(rtt)
if (rttHistory.size > 60) {
rttHistory.removeAt(0)
}

// Calculate max, min, and average RTT
val maxRtt = rttHistory.maxOrNull() ?: 0L
val minRtt = rttHistory.minOrNull() ?: 0L
val averageRtt = if (rttHistory.isNotEmpty()) {
rttHistory.average().toLong()
} else {
0L
}

// Update OWD state
owdState.longValue = owd

// Update OWD history
owdHistory.add(owd)
if (owdHistory.size > 60) {
owdHistory.removeAt(0)
}

// Calculate max, min, and average OWD
val maxOwd = owdHistory.maxOrNull() ?: 0L
val minOwd = owdHistory.minOrNull() ?: 0L
val averageOwd = if (owdHistory.isNotEmpty()) {
owdHistory.average().toLong()
} else {
0L
}

Log.d(TAG, "RTT - Latest: $rtt ms, Max: $maxRtt ms, Min: $minRtt ms, Average: $averageRtt ms")
Log.d(TAG, "OWD - Latest: $owd ms, Max: $maxOwd ms, Min: $minOwd ms, Average: $averageOwd ms")
}
}

else -> {
Log.e(TAG, "Unknown signaling type: ${data.getString("type")}")
}
}
}

private fun requestTimeSync() {
val t1 = System.currentTimeMillis()
val syncRequest = JSONObject().apply {
put("type", "time_sync_request")
put("room", currentRoom)
put("t1", t1)
}
socket.emit("signal", syncRequest)
Log.d(TAG, "Sent time sync request at t1: $t1")
}

override fun onDestroyView() {
super.onDestroyView()
statsJob?.cancel()
socket.disconnect()
localPeer?.dispose()
localView?.release()
localEglBase?.release()
}
}

class VideoReceiverFragment : Fragment() {

companion object {
fun newInstance(
room: String,
stunUrl: String,
turnUrl: String,
turnUsername: String,
turnPassword: String,
signalingServerUrl: String
): VideoReceiverFragment {
val fragment = VideoReceiverFragment()
val args = Bundle().apply {
putString("room", room)
putString("stunUrl", stunUrl)
putString("turnUrl", turnUrl)
putString("turnUsername", turnUsername)
putString("turnPassword", turnPassword)
putString("signalingServerUrl", signalingServerUrl)
}
fragment.arguments = args
return fragment
}
}

// Class member variables
private lateinit var socket: Socket
private var localPeer: PeerConnection? = null
private var remoteView: SurfaceViewRenderer? = null
private var remoteEglBase: EglBase? = null
private val pendingIceCandidates = mutableListOf<IceCandidate>()
private var currentRoom: String? = null
private lateinit var signalingServerUrl: String
private lateinit var stunUrl: String
private lateinit var turnUrl: String
private lateinit var turnUsername: String
private lateinit var turnPassword: String
private val TAG: String = "WebRTC-Receiver"

// State variables for RTT and OWD (if needed)
private val rttState = mutableLongStateOf(0L)
private val owdState = mutableLongStateOf(0L)
private val rttHistory = mutableStateListOf<Long>()
private val owdHistory = mutableStateListOf<Long>()

private val frameRateState = mutableDoubleStateOf(0.0)
private val bitrateState = mutableLongStateOf(0L)
private val stutteringState = mutableStateOf(false)

private val frameRateLowState = mutableStateOf(false)
private val packetLossHighState = mutableStateOf(false)
private val packetLossState = mutableDoubleStateOf(0.0)

private val frameRateHistory = mutableStateListOf<Float>()
private val bitrateHistory = mutableStateListOf<Long>()
private var timeSyncJob: Job? = null

// History variables
private var prevFramesDecoded = 0.0
private var prevBytesReceived = 0.0
private var prevFramesReceived = 0.0
private var prevFramesDropped = 0.0
private var prevTimestamp = 0.0
private var timeOffset: Long = 0
private var t1: Long = 0

private var statsJob: Job? = null

override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)

// Retrieve data from arguments
currentRoom = arguments?.getString("room") ?: "default-room"
signalingServerUrl = arguments?.getString("signalingServerUrl") ?: "https://wstszx.us.kg"
stunUrl = arguments?.getString("stunUrl") ?: "stun:stun.wstszx.us.kg:3478"
turnUrl = arguments?.getString("turnUrl") ?: "turn:turn.wstszx.us.kg:5349"
turnUsername = arguments?.getString("turnUsername") ?: "wstszx"
turnPassword = arguments?.getString("turnPassword") ?: "930379"

Log.d(
TAG,
"onCreate: Role = Client, Room = $currentRoom, Signaling Server = $signalingServerUrl, STUN URL = $stunUrl, TURN URL = $turnUrl"
)
}

private val requestPermissionsLauncher =
registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
permissions.entries.forEach { (permission, isGranted) ->
if (isGranted) {
Toast.makeText(requireContext(), "$permission 权限已授予", Toast.LENGTH_SHORT).show()
} else {
Toast.makeText(requireContext(), "$permission 权限被拒绝", Toast.LENGTH_SHORT).show()
}
}
onPermissionsChecked()
}

override fun onCreateView(
inflater: android.view.LayoutInflater,
container: android.view.ViewGroup?,
savedInstanceState: Bundle?
): android.view.View {
return ComposeView(requireContext()).apply {
setContent {
WebRTCComposeLayout()
}
}
}

@Composable
fun WebRTCComposeLayout() {
val context = LocalContext.current
lateinit var peerConnectionFactory: PeerConnectionFactory

Surface(color = Color.Black) {
Column(modifier = Modifier.fillMaxSize()) {

// Remote video view

Spacer(modifier = Modifier.height(8.dp))

// Display RTT and OWD (if needed)
Column(modifier = Modifier.padding(horizontal = 16.dp)) {
Text(
text = "往返时延 (RTT): ${rttState.longValue} ms",
color = Color.White,
style = MaterialTheme.typography.bodyMedium,
modifier = Modifier.padding(bottom = 4.dp)
)
Text(
text = "单向时延 (OWD): ${owdState.longValue} ms",
color = Color.White,
style = MaterialTheme.typography.bodyMedium,
modifier = Modifier.padding(bottom = 8.dp)
)
}

// Existing UI components for frame rate, bitrate, etc.

// Spacer between video and charts
Spacer(modifier = Modifier.height(8.dp))

// Frame Rate Section
Column(
modifier = Modifier
.fillMaxWidth()
.padding(horizontal = 8.dp)
) {
// Frame Rate Text in Chinese
Text(
text = "帧率: ${frameRateState.doubleValue.roundToInt()} fps",
color = Color.White,
style = MaterialTheme.typography.bodyMedium,
modifier = Modifier.padding(bottom = 4.dp)
)
Log.d(
TAG,
"UI - Frame Rate: ${frameRateState.doubleValue} fps, Bitrate: ${bitrateState.longValue / 1000} kbps"
)

// Line Chart for Frame Rate
LineChart(
data = frameRateHistory,
modifier = Modifier
.height(200.dp)
.fillMaxWidth()
.padding(vertical = 8.dp),
lineColor = Color.Green,
backgroundColor = Color.Black,
yAxisLabel = "帧率 (fps)",
xAxisLabel = "时间 (秒)"
)
}

// Spacer between charts
Spacer(modifier = Modifier.height(8.dp))

// Bitrate Section
Column(
modifier = Modifier
.fillMaxWidth()
.padding(horizontal = 16.dp)
) {
// Bitrate Text in Chinese
Text(
text = "码率: ${bitrateState.longValue / 1000} kbps",
color = Color.White,
style = MaterialTheme.typography.bodyMedium,
modifier = Modifier.padding(bottom = 4.dp)
)

// Line Chart for Bitrate
LineChart(
data = bitrateHistory.map { it / 1000f }, // Convert to kbps
modifier = Modifier
.height(200.dp)
.fillMaxWidth()
.padding(vertical = 8.dp),
lineColor = Color.Blue,
backgroundColor = Color.Black,
yAxisLabel = "码率 (kbps)",
xAxisLabel = "时间 (秒)"
)
}

// Spacer between metrics and stuttering indicator
Spacer(modifier = Modifier.height(16.dp))

// Stuttering Indicator
Row(
modifier = Modifier
.fillMaxWidth()
.padding(horizontal = 16.dp),
verticalAlignment = Alignment.CenterVertically
) {
if (stutteringState.value) {
Icon(
imageVector = Icons.Default.Warning,
contentDescription = "卡顿警告",
tint = Color.Red,
modifier = Modifier.size(24.dp)
)
Spacer(modifier = Modifier.width(8.dp))
Column {
Text(
text = "视频播放出现卡顿",
color = Color.Red,
style = MaterialTheme.typography.bodyMedium
)
// Additional information about which metrics are abnormal
if (frameRateLowState.value) {
Text(
text = "帧率过低: ${frameRateState.doubleValue.roundToInt()} fps",
color = Color.Red,
style = MaterialTheme.typography.bodySmall
)
}
if (packetLossHighState.value) {
Text(
text = "包丢失率过高: ${packetLossState.doubleValue.roundToInt()}%",
color = Color.Red,
style = MaterialTheme.typography.bodySmall
)
}
}
} else {
Icon(
imageVector = Icons.Default.CheckCircle,
contentDescription = "正常",
tint = Color.Green,
modifier = Modifier.size(24.dp)
)
Spacer(modifier = Modifier.width(8.dp))
Text(
text = "视频播放正常",
color = Color.Green,
style = MaterialTheme.typography.bodyMedium
)
}
}
}

LaunchedEffect(Unit) {
val options = PeerConnectionFactory.InitializationOptions.builder(context)
.createInitializationOptions()
PeerConnectionFactory.initialize(options)

val encoderFactory = DefaultVideoEncoderFactory(
EglBase.create().eglBaseContext, true, true
)

val decoderFactory = DefaultVideoDecoderFactory(remoteEglBase!!.eglBaseContext)

peerConnectionFactory = PeerConnectionFactory.builder()
.setVideoEncoderFactory(encoderFactory)
.setVideoDecoderFactory(decoderFactory)
.createPeerConnectionFactory()

createPeerConnection(
context,
peerConnectionFactory,
remoteView!!
) {
localPeer = it
}

initializeSocketIO()

requestPermissionsIfNeeded()
}
}
}

/**
* Enhanced Line Chart Composable with Axes and Labels
* Modified to use straight lines connecting each point
*/
@Composable
fun LineChart(
data: List<Float>,
modifier: Modifier = Modifier,
lineColor: Color = Color.Green,
backgroundColor: Color = Color.Black,
yAxisLabel: String = "",
xAxisLabel: String = "",
minYValue: Float? = null,
maxYValue: Float? = null
) {
}

private fun initializeSocketIO() {
val protocol = if (signalingServerUrl.startsWith("https")) "https" else "http"
val socketUrl = signalingServerUrl

val options = IO.Options().apply {
transports = arrayOf("websocket")
secure = protocol == "https"
path = "/socket.io/"
}

try {
socket = IO.socket(socketUrl, options)

socket.on(Socket.EVENT_CONNECT) {
Log.d(TAG, "Socket connected")
socket.emit("join", currentRoom)
Log.d(TAG, "Joined room: $currentRoom")
initiateCall()
}

socket.on(Socket.EVENT_CONNECT_ERROR) { args ->
if (args.isNotEmpty()) {
val error = args[0]
Log.e(TAG, "Socket connection error: $error")
}
}

socket.on(Socket.EVENT_DISCONNECT) { args ->
if (args.isNotEmpty()) {
val reason = args[0]
Log.d(TAG, "Socket disconnected: $reason")
}
}

socket.on("signal") { args ->
Log.d(TAG, "Received signaling: ${args[0]}")
if (args.isNotEmpty() && args[0] is JSONObject) {
val data = args[0] as JSONObject
handleSignalingData(data)
}
}

socket.connect()
Log.d(TAG, "Connecting to Socket: $socketUrl...")
} catch (e: Exception) {
Log.e(TAG, "Error connecting to Socket: ${e.message}")
}
}

private fun requestPermissionsIfNeeded() {
}

private fun onPermissionsChecked() {
Toast.makeText(requireContext(), "所有必要的权限已授予", Toast.LENGTH_SHORT).show()
}

private fun createPeerConnection(
context: Context,
peerConnectionFactory: PeerConnectionFactory,
remoteView: SurfaceViewRenderer,
onLocalPeerCreated: (PeerConnection) -> Unit
) {
}

private fun initiateCall() {
}

private fun handleSignalingData(data: JSONObject) {
Log.d(TAG, "Handling signaling data: $data")
when (data.getString("type")) {

"answer" -> {
Log.d(TAG, "Received answer")
val sdp = SessionDescription(
SessionDescription.Type.ANSWER,
data.getJSONObject("sdp").getString("sdp")
)

localPeer?.setRemoteDescription(object : SdpObserver {
override fun onSetSuccess() {
pendingIceCandidates.forEach { candidate ->
localPeer?.addIceCandidate(candidate)
}

pendingIceCandidates.clear()

Log.d(TAG, "Set remote description (answer) success")
}

override fun onSetFailure(error: String?) {
Log.e(TAG, "Set remote description error: $error")
}

override fun onCreateSuccess(p0: SessionDescription?) {}
override fun onCreateFailure(p0: String?) {}
}, sdp)
}

"ice" -> {
Log.d(TAG, "Received ICE candidate")
val candidateData = data.getJSONObject("candidate")
val candidate = IceCandidate(
candidateData.getString("sdpMid"),
candidateData.getInt("sdpMLineIndex"),
candidateData.getString("candidate")
)

if (localPeer?.remoteDescription != null) {
localPeer?.addIceCandidate(candidate)
} else {
pendingIceCandidates.add(candidate)
}
}

"time_sync_request" -> {
val t1 = data.getLong("t1")
val t2 = System.currentTimeMillis()
val t3 = System.currentTimeMillis()
val syncResponse = JSONObject().apply {
put("type", "time_sync_response")
put("t1", t1)
put("t2", t2)
put("t3", t3)
put("room", currentRoom)
}
socket.emit("signal", syncResponse)
Log.d(TAG, "Replied to time_sync_request: t1=$t1, t2=$t2, t3=$t3")
}

else -> {
Log.e(TAG, "Unknown signaling type: ${data.getString("type")}")
}
}
}

private fun startStatsCollection() {
Log.d(TAG, "Starting stats collection...")
statsJob = viewLifecycleOwner.lifecycleScope.launch {
while (isActive) {
delay(1000) // Collect stats every second
Log.d(TAG, "Collecting stats...")
localPeer?.getStats { report ->
Log.d(TAG, "Stats report obtained.")
parseStatsReport(report)
} ?: Log.e(TAG, "Failed to get stats: localPeer is null.")
}
}
}

private fun parseStatsReport(report: RTCStatsReport) {
Log.d(TAG, "Received RTCStatsReport: $report")
for (stats in report.statsMap.values) {
if (stats.type == "inbound-rtp") {
val kind = stats.members["kind"] as? String
if (kind == "video") {
val framesDecoded = (stats.members["framesDecoded"] as? Number)?.toDouble() ?: 0.0
val framesReceived = (stats.members["framesReceived"] as? Number)?.toDouble() ?: 0.0
val framesDropped = (stats.members["framesDropped"] as? Number)?.toDouble() ?: 0.0
val bytesReceived = (stats.members["bytesReceived"] as? Number)?.toDouble() ?: 0.0
val packetsLost = (stats.members["packetsLost"] as? Number)?.toDouble() ?: 0.0
val packetsReceived = (stats.members["packetsReceived"] as? Number)?.toDouble() ?: 1.0 // Avoid division by zero
val packetLossFraction = packetsLost / (packetsLost + packetsReceived)
val timestamp = stats.timestampUs / 1_000_000.0 // Convert to seconds

Log.d(
TAG,
"Stats - Frames Decoded: $framesDecoded, Frames Received: $framesReceived, Frames Dropped: $framesDropped, Bytes Received: $bytesReceived, Packet Loss Fraction: $packetLossFraction, Timestamp: $timestamp"
)

if (prevTimestamp != 0.0) {
val timeElapsed = timestamp - prevTimestamp
val framesDelta = framesDecoded - prevFramesDecoded
val bytesDelta = bytesReceived - prevBytesReceived
val framesReceivedDelta = framesReceived - prevFramesReceived
val framesDroppedDelta = framesDropped - prevFramesDropped

val frameRate = if (timeElapsed > 0) framesDelta / timeElapsed else 0.0
val bitrate = if (timeElapsed > 0) (bytesDelta * 8) / timeElapsed else 0.0 // bits per second
val packetLoss = packetLossFraction * 100 // Convert to percentage

Log.d(TAG, "Calculated Frame Rate: $frameRate fps, Bitrate: $bitrate bps, Packet Loss: $packetLoss%")

// Determine stuttering based on thresholds
val isStuttering = frameRate < 24 || packetLoss > 5.0 // Thresholds can be adjusted

// Update states
viewLifecycleOwner.lifecycleScope.launch {
frameRateState.doubleValue = frameRate
bitrateState.longValue = bitrate.toLong()
// Update stuttering state
stutteringState.value = isStuttering
// Update specific stuttering causes
frameRateLowState.value = frameRate < 24
packetLossHighState.value = packetLoss > 5.0
packetLossState.doubleValue = packetLoss

// Update history
frameRateHistory.add(frameRate.toFloat())
if (frameRateHistory.size > 60) {
frameRateHistory.removeAt(0)
}

bitrateHistory.add(bitrate.toLong())
if (bitrateHistory.size > 60) {
bitrateHistory.removeAt(0)
}

Log.d(
TAG,
"Updated Frame Rate: ${frameRateState.doubleValue} fps, Bitrate: ${bitrateState.longValue / 1000} kbps, Stuttering: $isStuttering"
)
}
}

// Update previous values
prevFramesDecoded = framesDecoded
prevBytesReceived = bytesReceived
prevFramesReceived = framesReceived
prevFramesDropped = framesDropped
prevTimestamp = timestamp
}
}
}
}

override fun onDestroyView() {
super.onDestroyView()
statsJob?.cancel()
socket.disconnect()
localPeer?.dispose()
remoteView?.release()
remoteEglBase?.release()
timeSyncJob?.cancel()
}
}

单向时延和往返时延的统计方案应该用同一个请求来计算，并且将值展示在界面上，发起端展示往返最新、最大、最小和平均时延，接收端展示单向最新、最大、最小和平均时延，返回给我修改后的代码

الفكرة

合并时间同步

正在思考如何单独请求时间同步，并同时计算和展示往返时间（RTT）和单向延迟（OWD），以简化代码。

改进时间同步

确保时间同步请求共同计算RTT和OWD，并相应更新UI，显示各自的指标。使用Compose UI进行适当的代码处理。

修改类结构

正在调整 VideoInitiatorFragment 和 VideoReceiverFragment 类，确保使用单个请求同步时间并计算 RTT 和 OWD，同时更新 UI 显示相应指标。

跟踪时间同步同步

我正在处理VideoInitiatorFragment和VideoReceiverFragment类，分别计算RTT和OWD，并更新UI以显示最新、最大、最小和平均值。这些修改能够提升数据的准确性和全貌呈现。

聚焦关键指标

我正在调整代码以加强视频发起者和接收者的界面显示。在视频发起者界面上，确保只显示往返时延 (RTT) 指标，而不是单向时延 (OWD)。

计算延迟时间

我正在计算各节点之间的延迟时间，包括请求到接收、接收到接收器的回复，以及接收器到发起者的回复。预计发起者到接收器的往返时延会更长。

探讨OWD计算方法
我想要确定接收方是否计算OWD并发送给发起方，或者发起方计算并发送给接收方，而接收方计算自己的OWD。发起方可以计算RTT和OWD，并在UI中显示RTT指标，接收方则显示OWD指标。

对OWD的持续监控

VideoReceiverFragment正在测量和记录OWD。接收到时间同步请求后，立即回复t1, t2, t3，并计算和展示最新的OWD值。这一步骤确保了实时数据的准确性。

拆解延迟

Initiator应展示RTT，Receiver应展示OWD。调整Fragment中的显示，确保信息传达准确。

调整计算方法

收发双方正在逐步调整，发送方仅计算RTT，接收方则负责计算并存储OWD。这更符合各自的任务和需求。

调整数据存储

我正在弄清晰VideoInitiatorFragment的变量设置，把owdState和owdHistory移除，专注于RTT指标。

更新UI以反映延迟

正在处理延迟数据时，我发现计算RTT和OWD，并且打算将RTT显示在Initiator，OWD显示在Receiver上。这样可以更清晰地展示延迟变化。

更新显示数据

我正在处理 time_sync_request，来计算深度测量时间，并更新哇!动态历史记录，同时还要调整界面来显示最新、最大、最小和平均值。这真是一个精细的调整过程。

进行代码改动

正在调整代码，移除多余的状态，计算并更新RTT和OWD数据，确保UI能够显示最新的指标。我也在考虑请求权限和其他未实现的函数。

الإجابة

Certainly! Below are the modified versions of both VideoInitiatorFragment and VideoReceiverFragment classes. These modifications ensure that a single time synchronization request is used to calculate both Round-Trip Time (RTT) and One-Way Delay (OWD). The initiator (VideoInitiatorFragment) will display RTT metrics (latest, maximum, minimum, and average), while the receiver (VideoReceiverFragment) will display OWD metrics (latest, maximum, minimum, and average).

Key Changes:

Unified Time Synchronization: Both fragments use a single time synchronization request to calculate RTT and OWD.
Metric Tracking:
- The initiator tracks RTT metrics.
- The receiver tracks OWD metrics.
UI Updates:
- The initiator displays RTT (latest, max, min, average).
- The receiver displays OWD (latest, max, min, average).

Modified `VideoInitiatorFragment`:

class VideoInitiatorFragment : Fragment() {

    // Class member variables
    private lateinit var socket: Socket
    private var localPeer: PeerConnection? = null
    private var localView: SurfaceViewRenderer? = null
    private var localEglBase: EglBase? = null
    private val pendingIceCandidates = mutableListOf<IceCandidate>()
    private var currentRoom: String? = null
    private lateinit var signalingServerUrl: String
    private lateinit var stunUrl: String
    private lateinit var turnUrl: String
    private lateinit var turnUsername: String
    private lateinit var turnPassword: String

    private val TAG: String = "WebRTC-Initiator"

    // State variables for RTT
    private val rttState = mutableLongStateOf(0L)
    private val rttHistory = mutableStateListOf<Long>()

    // Statistics job
    private var statsJob: Job? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // Retrieve data from arguments
        currentRoom = arguments?.getString("room") ?: "default-room"
        signalingServerUrl = arguments?.getString("signalingServerUrl") ?: "https://wstszx.us.kg"
        stunUrl = arguments?.getString("stunUrl") ?: "stun:stun.wstszx.us.kg:3478"
        turnUrl = arguments?.getString("turnUrl") ?: "turn:turn.wstszx.us.kg:5349"
        turnUsername = arguments?.getString("turnUsername") ?: "wstszx"
        turnPassword = arguments?.getString("turnPassword") ?: "930379"

        Log.d(
            TAG,
            "onCreate: Role = Initiator, Room = $currentRoom, Signaling Server = $signalingServerUrl, STUN URL = $stunUrl, TURN URL = $turnUrl"
        )
    }

    private val requestPermissionsLauncher =
        registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
            permissions.entries.forEach { (permission, isGranted) ->
                if (isGranted) {
                    Toast.makeText(requireContext(), "$permission 权限已授予", Toast.LENGTH_SHORT).show()
                } else {
                    Toast.makeText(requireContext(), "$permission 权限被拒绝", Toast.LENGTH_SHORT).show()
                }
            }
            onPermissionsChecked()
        }

    override fun onCreateView(
        inflater: android.view.LayoutInflater,
        container: android.view.ViewGroup?,
        savedInstanceState: Bundle?
    ): android.view.View {
        return ComposeView(requireContext()).apply {
            setContent {
                WebRTCComposeLayout()
            }
        }
    }

    @Composable
    fun WebRTCComposeLayout() {
        val context = LocalContext.current
        lateinit var peerConnectionFactory: PeerConnectionFactory
        var localVideoTrack: VideoTrack? by remember { mutableStateOf(null) }

        Surface(color = Color.Black) {
            Column(modifier = Modifier.fillMaxSize()) {

                // Spacer or additional UI components can be placed here

                Spacer(modifier = Modifier.height(8.dp))

                // Display RTT Metrics
                Column(modifier = Modifier.padding(horizontal = 16.dp)) {
                    Text(
                        text = "往返时延 (RTT) 最新: ${rttState.longValue} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "RTT 最大: ${rttHistory.maxOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "RTT 最小: ${rttHistory.minOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    val averageRtt = if (rttHistory.isNotEmpty()) rttHistory.average().toLong() else 0L
                    Text(
                        text = "RTT 平均: $averageRtt ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 8.dp)
                    )
                }

                // Additional UI components can go here...

            }

            LaunchedEffect(Unit) {
                val options = PeerConnectionFactory.InitializationOptions.builder(context)
                    .createInitializationOptions()
                PeerConnectionFactory.initialize(options)

                val encoderFactory = DefaultVideoEncoderFactory(
                    localEglBase!!.eglBaseContext, true, true
                )

                val decoderFactory = DefaultVideoDecoderFactory(localEglBase!!.eglBaseContext)

                peerConnectionFactory = PeerConnectionFactory.builder()
                    .setVideoEncoderFactory(encoderFactory)
                    .setVideoDecoderFactory(decoderFactory)
                    .createPeerConnectionFactory()

                initLocalVideo(context, localView, peerConnectionFactory, localEglBase!!) {
                    localVideoTrack = it
                }

                createPeerConnection(
                    context,
                    peerConnectionFactory,
                    localVideoTrack
                ) {
                    localPeer = it
                    startStatsCollection() // Start collecting statistics
                }

                initializeSocketIO()

                requestPermissionsIfNeeded()
                startTimeSync()
            }
        }
    }

    private fun startTimeSync(intervalMs: Long = 5000L) {
        viewLifecycleOwner.lifecycleScope.launch {
            while (isActive) {
                delay(intervalMs) // Sync every 5 seconds
                requestTimeSync()
            }
        }
    }

    private fun startStatsCollection() {
        statsJob = viewLifecycleOwner.lifecycleScope.launch {
            while (isActive) {
                delay(1000) // Collect stats every second
                localPeer?.getStats { report ->
                    parseStatsReport(report)
                } ?: Log.e(TAG, "Failed to get stats: localPeer is null.")
            }
        }
    }

    private fun parseStatsReport(report: RTCStatsReport) {
        // Implementation for stats parsing (if needed)
    }

    private fun initializeSocketIO() {
        val protocol = if (signalingServerUrl.startsWith("https")) "https" else "http"
        val socketUrl = signalingServerUrl

        val options = IO.Options().apply {
            transports = arrayOf("websocket")
            secure = protocol == "https"
            path = "/socket.io/"
        }

        try {
            socket = IO.socket(socketUrl, options)

            socket.on(Socket.EVENT_CONNECT) {
                Log.d(TAG, "Socket connected")
                socket.emit("join", currentRoom)
                Log.d(TAG, "Joined room: $currentRoom")
            }

            socket.on(Socket.EVENT_CONNECT_ERROR) { args ->
                if (args.isNotEmpty()) {
                    val error = args[0]
                    Log.e(TAG, "Socket connection error: $error")
                }
            }

            socket.on(Socket.EVENT_DISCONNECT) { args ->
                if (args.isNotEmpty()) {
                    val reason = args[0]
                    Log.d(TAG, "Socket disconnected: $reason")
                }
            }

            socket.on("signal") { args ->
                Log.d(TAG, "Received signaling: ${args[0]}")
                if (args.isNotEmpty() && args[0] is JSONObject) {
                    val data = args[0] as JSONObject
                    handleSignalingData(data)
                }
            }

            socket.connect()
            Log.d(TAG, "Connecting to Socket: $socketUrl...")
        } catch (e: Exception) {
            Log.e(TAG, "Error connecting to Socket: ${e.message}")
        }
    }

    private fun requestPermissionsIfNeeded() {
        // Implementation for requesting permissions
        // Example:
        val permissions = arrayOf(
            Manifest.permission.CAMERA,
            Manifest.permission.RECORD_AUDIO
        )
        requestPermissionsLauncher.launch(permissions)
    }

    private fun onPermissionsChecked() {
        Toast.makeText(requireContext(), "所有必要权限已被授予", Toast.LENGTH_SHORT).show()
        // Proceed with initializing video or other components
    }

    private fun initLocalVideo(
        context: Context,
        localView: SurfaceViewRenderer?,
        peerConnectionFactory: PeerConnectionFactory,
        eglBase: EglBase,
        onLocalVideoTrack: (VideoTrack) -> Unit
    ) {
        // Implementation for initializing local video
    }

    private fun createCameraCapturer(context: Context): CameraVideoCapturer {
        // Implementation for creating camera capturer
        // Example:
        val cameraEnumerator = Camera2Enumerator(context)
        val deviceNames = cameraEnumerator.deviceNames
        for (deviceName in deviceNames) {
            if (cameraEnumerator.isFrontFacing(deviceName)) {
                return cameraEnumerator.createCapturer(deviceName, null)!!
            }
        }
        throw RuntimeException("No front-facing camera found.")
    }

    private fun createPeerConnection(
        context: Context,
        peerConnectionFactory: PeerConnectionFactory,
        localVideoTrack: VideoTrack?,
        onLocalPeerCreated: (PeerConnection) -> Unit
    ) {
        // Implementation for creating peer connection
    }

    private fun createAnswer(peerConnection: PeerConnection, onAnswerCreated: (String) -> Unit) {
        Log.d(TAG, "Creating answer...")
        // Implementation for creating an answer
    }

    private fun handleSignalingData(data: JSONObject) {
        Log.d(TAG, "Handling signaling data: $data")
        when (data.getString("type")) {
            "offer" -> {
                Log.d(TAG, "Received offer")
                val sdp = SessionDescription(
                    SessionDescription.Type.OFFER,
                    data.getJSONObject("sdp").getString("sdp")
                )
                localPeer?.setRemoteDescription(object : SdpObserver {
                    override fun onSetSuccess() {
                        Log.d(TAG, "Set remote description (offer) success")
                        createAnswer(localPeer!!) { answer ->
                            val signalData = JSONObject().apply {
                                put("type", "answer")
                                put("sdp", JSONObject().put("sdp", answer))
                                put("room", currentRoom)
                            }

                            socket.emit("signal", signalData)
                            Log.d(TAG, "Sent answer SDP.")

                            pendingIceCandidates.forEach { candidate ->
                                localPeer?.addIceCandidate(candidate)
                            }
                            pendingIceCandidates.clear()
                        }
                    }

                    override fun onSetFailure(error: String?) {
                        Log.e(TAG, "Set remote description (offer) error: $error")
                    }

                    override fun onCreateSuccess(p0: SessionDescription?) {}
                    override fun onCreateFailure(p0: String?) {}
                }, sdp)
            }

            "answer" -> {
                Log.d(TAG, "Received answer")
                val sdp = SessionDescription(
                    SessionDescription.Type.ANSWER,
                    data.getJSONObject("sdp").getString("sdp")
                )
                localPeer?.setRemoteDescription(object : SdpObserver {
                    override fun onSetSuccess() {
                        pendingIceCandidates.forEach { candidate ->
                            localPeer?.addIceCandidate(candidate)
                        }
                        pendingIceCandidates.clear()
                        Log.d(TAG, "Set remote description (answer) success")
                    }

                    override fun onSetFailure(error: String?) {
                        Log.e(TAG, "Set remote description error: $error")
                    }

                    override fun onCreateSuccess(p0: SessionDescription?) {}
                    override fun onCreateFailure(p0: String?) {}
                }, sdp)
            }

            "ice" -> {
                Log.d(TAG, "Received ICE candidate")
                val candidateData = data.getJSONObject("candidate")
                val candidate = IceCandidate(
                    candidateData.getString("sdpMid"),
                    candidateData.getInt("sdpMLineIndex"),
                    candidateData.getString("candidate")
                )

                if (localPeer?.remoteDescription != null) {
                    localPeer?.addIceCandidate(candidate)
                } else {
                    pendingIceCandidates.add(candidate)
                }
            }

            "time_sync_response" -> {
                Log.d(TAG, "Received time_sync_response")
                val t1 = data.getLong("t1")
                val t2 = data.getLong("t2")
                val t3 = data.getLong("t3")
                val t4 = System.currentTimeMillis()

                // Calculate RTT
                val rtt = t4 - t1 - (t3 - t2)

                Log.d(TAG, "Time Sync: RTT=$rtt ms")

                viewLifecycleOwner.lifecycleScope.launch {
                    // Update RTT state
                    rttState.longValue = rtt

                    // Update RTT history
                    rttHistory.add(rtt)
                    if (rttHistory.size > 60) {
                        rttHistory.removeAt(0)
                    }

                    // Calculate max, min, and average RTT
                    val maxRtt = rttHistory.maxOrNull() ?: 0L
                    val minRtt = rttHistory.minOrNull() ?: 0L
                    val averageRtt = if (rttHistory.isNotEmpty()) {
                        rttHistory.average().toLong()
                    } else {
                        0L
                    }

                    Log.d(TAG, "RTT - Latest: $rtt ms, Max: $maxRtt ms, Min: $minRtt ms, Average: $averageRtt ms")
                }
            }

            else -> {
                Log.e(TAG, "Unknown signaling type: ${data.getString("type")}")
            }
        }
    }

    private fun requestTimeSync() {
        val t1 = System.currentTimeMillis()
        val syncRequest = JSONObject().apply {
            put("type", "time_sync_request")
            put("room", currentRoom)
            put("t1", t1)
        }
        socket.emit("signal", syncRequest)
        Log.d(TAG, "Sent time sync request at t1: $t1")
    }

    override fun onDestroyView() {
        super.onDestroyView()
        statsJob?.cancel()
        socket.disconnect()
        localPeer?.dispose()
        localView?.release()
        localEglBase?.release()
    }
}

Modified `VideoReceiverFragment`:

class VideoReceiverFragment : Fragment() {

    companion object {
        fun newInstance(
            room: String,
            stunUrl: String,
            turnUrl: String,
            turnUsername: String,
            turnPassword: String,
            signalingServerUrl: String
        ): VideoReceiverFragment {
            val fragment = VideoReceiverFragment()
            val args = Bundle().apply {
                putString("room", room)
                putString("stunUrl", stunUrl)
                putString("turnUrl", turnUrl)
                putString("turnUsername", turnUsername)
                putString("turnPassword", turnPassword)
                putString("signalingServerUrl", signalingServerUrl)
            }
            fragment.arguments = args
            return fragment
        }
    }

    // Class member variables
    private lateinit var socket: Socket
    private var localPeer: PeerConnection? = null
    private var remoteView: SurfaceViewRenderer? = null
    private var remoteEglBase: EglBase? = null
    private val pendingIceCandidates = mutableListOf<IceCandidate>()
    private var currentRoom: String? = null
    private lateinit var signalingServerUrl: String
    private lateinit var stunUrl: String
    private lateinit var turnUrl: String
    private lateinit var turnUsername: String
    private lateinit var turnPassword: String
    private val TAG: String = "WebRTC-Receiver"

    // State variables for OWD
    private val owdState = mutableLongStateOf(0L)
    private val owdHistory = mutableStateListOf<Long>()

    private val frameRateState = mutableDoubleStateOf(0.0)
    private val bitrateState = mutableLongStateOf(0L)
    private val stutteringState = mutableStateOf(false)

    private val frameRateLowState = mutableStateOf(false)
    private val packetLossHighState = mutableStateOf(false)
    private val packetLossState = mutableDoubleStateOf(0.0)

    private val frameRateHistory = mutableStateListOf<Float>()
    private val bitrateHistory = mutableStateListOf<Long>()
    private var timeSyncJob: Job? = null

    // History variables
    private var prevFramesDecoded = 0.0
    private var prevBytesReceived = 0.0
    private var prevFramesReceived = 0.0
    private var prevFramesDropped = 0.0
    private var prevTimestamp = 0.0
    private var timeOffset: Long = 0
    private var t1: Long = 0

    private var statsJob: Job? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // Retrieve data from arguments
        currentRoom = arguments?.getString("room") ?: "default-room"
        signalingServerUrl = arguments?.getString("signalingServerUrl") ?: "https://wstszx.us.kg"
        stunUrl = arguments?.getString("stunUrl") ?: "stun:stun.wstszx.us.kg:3478"
        turnUrl = arguments?.getString("turnUrl") ?: "turn:turn.wstszx.us.kg:5349"
        turnUsername = arguments?.getString("turnUsername") ?: "wstszx"
        turnPassword = arguments?.getString("turnPassword") ?: "930379"

        Log.d(
            TAG,
            "onCreate: Role = Client, Room = $currentRoom, Signaling Server = $signalingServerUrl, STUN URL = $stunUrl, TURN URL = $turnUrl"
        )
    }

    private val requestPermissionsLauncher =
        registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
            permissions.entries.forEach { (permission, isGranted) ->
                if (isGranted) {
                    Toast.makeText(requireContext(), "$permission 权限已授予", Toast.LENGTH_SHORT).show()
                } else {
                    Toast.makeText(requireContext(), "$permission 权限被拒绝", Toast.LENGTH_SHORT).show()
                }
            }
            onPermissionsChecked()
        }

    override fun onCreateView(
        inflater: android.view.LayoutInflater,
        container: android.view.ViewGroup?,
        savedInstanceState: Bundle?
    ): android.view.View {
        return ComposeView(requireContext()).apply {
            setContent {
                WebRTCComposeLayout()
            }
        }
    }

    @Composable
    fun WebRTCComposeLayout() {
        val context = LocalContext.current
        lateinit var peerConnectionFactory: PeerConnectionFactory

        Surface(color = Color.Black) {
            Column(modifier = Modifier.fillMaxSize()) {

                // Remote video view can be added here

                Spacer(modifier = Modifier.height(8.dp))

                // Display OWD Metrics
                Column(modifier = Modifier.padding(horizontal = 16.dp)) {
                    Text(
                        text = "单向时延 (OWD) 最新: ${owdState.longValue} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "OWD 最大: ${owdHistory.maxOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "OWD 最小: ${owdHistory.minOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    val averageOwd = if (owdHistory.isNotEmpty()) owdHistory.average().toLong() else 0L
                    Text(
                        text = "OWD 平均: $averageOwd ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 8.dp)
                    )
                }

                // Existing UI components for frame rate, bitrate, etc.

                // Spacer between video and charts
                Spacer(modifier = Modifier.height(8.dp))

                // Frame Rate Section
                Column(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 8.dp)
                ) {
                    // Frame Rate Text in Chinese
                    Text(
                        text = "帧率: ${frameRateState.doubleValue.roundToInt()} fps",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Log.d(
                        TAG,
                        "UI - Frame Rate: ${frameRateState.doubleValue} fps, Bitrate: ${bitrateState.longValue / 1000} kbps"
                    )

                    // Line Chart for Frame Rate
                    LineChart(
                        data = frameRateHistory,
                        modifier = Modifier
                            .height(200.dp)
                            .fillMaxWidth()
                            .padding(vertical = 8.dp),
                        lineColor = Color.Green,
                        backgroundColor = Color.Black,
                        yAxisLabel = "帧率 (fps)",
                        xAxisLabel = "时间 (秒)"
                    )
                }

                // Spacer between charts
                Spacer(modifier = Modifier.height(8.dp))

                // Bitrate Section
                Column(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 16.dp)
                ) {
                    // Bitrate Text in Chinese
                    Text(
                        text = "码率: ${bitrateState.longValue / 1000} kbps",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )

                    // Line Chart for Bitrate
                    LineChart(
                        data = bitrateHistory.map { it / 1000f }, // Convert to kbps
                        modifier = Modifier
                            .height(200.dp)
                            .fillMaxWidth()
                            .padding(vertical = 8.dp),
                        lineColor = Color.Blue,
                        backgroundColor = Color.Black,
                        yAxisLabel = "码率 (kbps)",
                        xAxisLabel = "时间 (秒)"
                    )
                }

                // Spacer between metrics and stuttering indicator
                Spacer(modifier = Modifier.height(16.dp))

                // Stuttering Indicator
                Row(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 16.dp),
                    verticalAlignment = Alignment.CenterVertically
                ) {
                    if (stutteringState.value) {
                        Icon(
                            imageVector = Icons.Default.Warning,
                            contentDescription = "卡顿警告",
                            tint = Color.Red,
                            modifier = Modifier.size(24.dp)
                        )
                        Spacer(modifier = Modifier.width(8.dp))
                        Column {
                            Text(
                                text = "视频播放出现卡顿",
                                color = Color.Red,
                                style = MaterialTheme.typography.bodyMedium
                            )
                            // Additional information about which metrics are abnormal
                            if (frameRateLowState.value) {
                                Text(
                                    text = "帧率过低: ${frameRateState.doubleValue.roundToInt()} fps",
                                    color = Color.Red,
                                    style = MaterialTheme.typography.bodySmall
                                )
                            }
                            if (packetLossHighState.value) {
                                Text(
                                    text = "包丢失率过高: ${packetLossState.doubleValue.roundToInt()}%",
                                    color = Color.Red,
                                    style = MaterialTheme.typography.bodySmall
                                )
                            }
                        }
                    } else {
                        Icon(
                            imageVector = Icons.Default.CheckCircle,
                            contentDescription = "正常",
                            tint = Color.Green,
                            modifier = Modifier.size(24.dp)
                        )
                        Spacer(modifier = Modifier.width(8.dp))
                        Text(
                            text = "视频播放正常",
                            color = Color.Green,
                            style = MaterialTheme.typography.bodyMedium
                        )
                    }
                }
            }

            LaunchedEffect(Unit) {
                val options = PeerConnectionFactory.InitializationOptions.builder(context)
                    .createInitializationOptions()
                PeerConnectionFactory.initialize(options)

                val encoderFactory = DefaultVideoEncoderFactory(
                    localEglBase!!.eglBaseContext, true, true
                )

                val decoderFactory = DefaultVideoDecoderFactory(remoteEglBase!!.eglBaseContext)

                peerConnectionFactory = PeerConnectionFactory.builder()
                    .setVideoEncoderFactory(encoderFactory)
                    .setVideoDecoderFactory(decoderFactory)
                    .createPeerConnectionFactory()

                createPeerConnection(
                    context,
                    peerConnectionFactory,
                    remoteView!!
                ) {
                    localPeer = it
                }

                initializeSocketIO()

                requestPermissionsIfNeeded()
            }
        }
    }

    /**
     * Enhanced Line Chart Composable with Axes and Labels
     * Modified to use straight lines connecting each point
     */
    @Composable
    fun LineChart(
        data: List<Float>,
        modifier: Modifier = Modifier,
        lineColor: Color = Color.Green,
        backgroundColor: Color = Color.Black,
        yAxisLabel: String = "",
        xAxisLabel: String = "",
        minYValue: Float? = null,
        maxYValue: Float? = null
    ) {
        // Implementation for the line chart
        // You can use Canvas to draw the chart or any chart library compatible with Compose
    }

    private fun initializeSocketIO() {
        val protocol = if (signalingServerUrl.startsWith("https")) "https" else "http"
        val socketUrl = signalingServerUrl

        val options = IO.Options().apply {
            transports = arrayOf("websocket")
            secure = protocol == "https"
            path = "/socket.io/"
        }

        try {
            socket = IO.socket(socketUrl, options)

            socket.on(Socket.EVENT_CONNECT) {
                Log.d(TAG, "Socket connected")
                socket.emit("join", currentRoom)
                Log.d(TAG, "Joined room: $currentRoom")
                initiateCall()
            }

            socket.on(Socket.EVENT_CONNECT_ERROR) { args ->
                if (args.isNotEmpty()) {
                    val error = args[0]
                    Log.e(TAG, "Socket connection error: $error")
                }
            }

            socket.on(Socket.EVENT_DISCONNECT) { args ->
                if (args.isNotEmpty()) {
                    val reason = args[0]
                    Log.d(TAG, "Socket disconnected: $reason")
                }
            }

            socket.on("signal") { args ->
                Log.d(TAG, "Received signaling: ${args[0]}")
                if (args.isNotEmpty() && args[0] is JSONObject) {
                    val data = args[0] as JSONObject
                    handleSignalingData(data)
                }
            }

            socket.connect()
            Log.d(TAG, "Connecting to Socket: $socketUrl...")
        } catch (e: Exception) {
            Log.e(TAG, "Error connecting to Socket: ${e.message}")
        }
    }

    private fun requestPermissionsIfNeeded() {
        // Implementation for requesting permissions
        // Example:
        val permissions = arrayOf(
            Manifest.permission.CAMERA,
            Manifest.permission.RECORD_AUDIO
        )
        requestPermissionsLauncher.launch(permissions)
    }

    private fun onPermissionsChecked() {
        Toast.makeText(requireContext(), "所有必要的权限已授予", Toast.LENGTH_SHORT).show()
        // Proceed with initializing video or other components
    }

    private fun createPeerConnection(
        context: Context,
        peerConnectionFactory: PeerConnectionFactory,
        remoteView: SurfaceViewRenderer,
        onLocalPeerCreated: (PeerConnection) -> Unit
    ) {
        // Implementation for creating peer connection
    }

    private fun initiateCall() {
        // Implementation to initiate call, e.g., create offer
    }

    private fun handleSignalingData(data: JSONObject) {
        Log.d(TAG, "Handling signaling data: $data")
        when (data.getString("type")) {

            "answer" -> {
                Log.d(TAG, "Received answer")
                val sdp = SessionDescription(
                    SessionDescription.Type.ANSWER,
                    data.getJSONObject("sdp").getString("sdp")
                )

                localPeer?.setRemoteDescription(object : SdpObserver {
                    override fun onSetSuccess() {
                        pendingIceCandidates.forEach { candidate ->
                            localPeer?.addIceCandidate(candidate)
                        }

                        pendingIceCandidates.clear()

                        Log.d(TAG, "Set remote description (answer) success")
                    }

                    override fun onSetFailure(error: String?) {
                        Log.e(TAG, "Set remote description error: $error")
                    }

                    override fun onCreateSuccess(p0: SessionDescription?) {}
                    override fun onCreateFailure(p0: String?) {}
                }, sdp)
            }

            "ice" -> {
                Log.d(TAG, "Received ICE candidate")
                val candidateData = data.getJSONObject("candidate")
                val candidate = IceCandidate(
                    candidateData.getString("sdpMid"),
                    candidateData.getInt("sdpMLineIndex"),
                    candidateData.getString("candidate")
                )

                if (localPeer?.remoteDescription != null) {
                    localPeer?.addIceCandidate(candidate)
                } else {
                    pendingIceCandidates.add(candidate)
                }
            }

            "time_sync_request" -> {
                val t1 = data.getLong("t1")
                val t2 = System.currentTimeMillis()
                val t3 = System.currentTimeMillis()
                val syncResponse = JSONObject().apply {
                    put("type", "time_sync_response")
                    put("t1", t1)
                    put("t2", t2)
                    put("t3", t3)
                    put("room", currentRoom)
                }
                socket.emit("signal", syncResponse)
                Log.d(TAG, "Replied to time_sync_request: t1=$t1, t2=$t2, t3=$t3")

                // Calculate OWD
                val owd = t2 - t1
                Log.d(TAG, "Time Sync: OWD=$owd ms")

                viewLifecycleOwner.lifecycleScope.launch {
                    // Update OWD state
                    owdState.longValue = owd

                    // Update OWD history
                    owdHistory.add(owd)
                    if (owdHistory.size > 60) {
                        owdHistory.removeAt(0)
                    }

                    // Calculate max, min, and average OWD
                    val maxOwd = owdHistory.maxOrNull() ?: 0L
                    val minOwd = owdHistory.minOrNull() ?: 0L
                    val averageOwd = if (owdHistory.isNotEmpty()) {
                        owdHistory.average().toLong()
                    } else {
                        0L
                    }

                    Log.d(TAG, "OWD - Latest: $owd ms, Max: $maxOwd ms, Min: $minOwd ms, Average: $averageOwd ms")
                }
            }

            else -> {
                Log.e(TAG, "Unknown signaling type: ${data.getString("type")}")
            }
        }
    }

    private fun startStatsCollection() {
        Log.d(TAG, "Starting stats collection...")
        statsJob = viewLifecycleOwner.lifecycleScope.launch {
            while (isActive) {
                delay(1000) // Collect stats every second
                Log.d(TAG, "Collecting stats...")
                localPeer?.getStats { report ->
                    Log.d(TAG, "Stats report obtained.")
                    parseStatsReport(report)
                } ?: Log.e(TAG, "Failed to get stats: localPeer is null.")
            }
        }
    }

    private fun parseStatsReport(report: RTCStatsReport) {
        Log.d(TAG, "Received RTCStatsReport: $report")
        for (stats in report.statsMap.values) {
            if (stats.type == "inbound-rtp") {
                val kind = stats.members["kind"] as? String
                if (kind == "video") {
                    val framesDecoded = (stats.members["framesDecoded"] as? Number)?.toDouble() ?: 0.0
                    val framesReceived = (stats.members["framesReceived"] as? Number)?.toDouble() ?: 0.0
                    val framesDropped = (stats.members["framesDropped"] as? Number)?.toDouble() ?: 0.0
                    val bytesReceived = (stats.members["bytesReceived"] as? Number)?.toDouble() ?: 0.0
                    val packetsLost = (stats.members["packetsLost"] as? Number)?.toDouble() ?: 0.0
                    val packetsReceived = (stats.members["packetsReceived"] as? Number)?.toDouble() ?: 1.0 // Avoid division by zero
                    val packetLossFraction = packetsLost / (packetsLost + packetsReceived)
                    val timestamp = stats.timestampUs / 1_000_000.0 // Convert to seconds

                    Log.d(
                        TAG,
                        "Stats - Frames Decoded: $framesDecoded, Frames Received: $framesReceived, Frames Dropped: $framesDropped, Bytes Received: $bytesReceived, Packet Loss Fraction: $packetLossFraction, Timestamp: $timestamp"
                    )

                    if (prevTimestamp != 0.0) {
                        val timeElapsed = timestamp - prevTimestamp
                        val framesDelta = framesDecoded - prevFramesDecoded
                        val bytesDelta = bytesReceived - prevBytesReceived
                        val framesReceivedDelta = framesReceived - prevFramesReceived
                        val framesDroppedDelta = framesDropped - prevFramesDropped

                        val frameRate = if (timeElapsed > 0) framesDelta / timeElapsed else 0.0
                        val bitrate = if (timeElapsed > 0) (bytesDelta * 8) / timeElapsed else 0.0 // bits per second
                        val packetLoss = packetLossFraction * 100 // Convert to percentage

                        Log.d(TAG, "Calculated Frame Rate: $frameRate fps, Bitrate: $bitrate bps, Packet Loss: $packetLoss%")

                        // Determine stuttering based on thresholds
                        val isStuttering = frameRate < 24 || packetLoss > 5.0 // Thresholds can be adjusted

                        // Update states
                        viewLifecycleOwner.lifecycleScope.launch {
                            frameRateState.doubleValue = frameRate
                            bitrateState.longValue = bitrate.toLong()
                            // Update stuttering state
                            stutteringState.value = isStuttering
                            // Update specific stuttering causes
                            frameRateLowState.value = frameRate < 24
                            packetLossHighState.value = packetLoss > 5.0
                            packetLossState.doubleValue = packetLoss

                            // Update history
                            frameRateHistory.add(frameRate.toFloat())
                            if (frameRateHistory.size > 60) {
                                frameRateHistory.removeAt(0)
                            }

                            bitrateHistory.add(bitrate.toLong())
                            if (bitrateHistory.size > 60) {
                                bitrateHistory.removeAt(0)
                            }

                            Log.d(
                                TAG,
                                "Updated Frame Rate: ${frameRateState.doubleValue} fps, Bitrate: ${bitrateState.longValue / 1000} kbps, Stuttering: $isStuttering"
                            )
                        }
                    }

                    // Update previous values
                    prevFramesDecoded = framesDecoded
                    prevBytesReceived = bytesReceived
                    prevFramesReceived = framesReceived
                    prevFramesDropped = framesDropped
                    prevTimestamp = timestamp
                }
            }
        }
    }

    override fun onDestroyView() {
        super.onDestroyView()
        statsJob?.cancel()
        socket.disconnect()
        localPeer?.dispose()
        remoteView?.release()
        remoteEglBase?.release()
        timeSyncJob?.cancel()
    }
}

Explanation of Changes:

Removed OWD Tracking from Initiator:
- Variables Removed:
  - private val owdState = mutableLongStateOf(0L)
  - private val owdHistory = mutableStateListOf<Long>()
- UI Adjustments:
  - Removed the display of OWD in the initiator's UI.
  - Added display for RTT metrics: latest, max, min, and average.
- Signaling Data Handling:
  - In handleSignalingData, under "time_sync_response", only RTT is calculated and tracked.
Added OWD Tracking to Receiver:
- Variables Added:
  - private val owdState = mutableLongStateOf(0L)
  - private val owdHistory = mutableStateListOf<Long>()
- Removed RTT Tracking:
  - Removed variables related to RTT (rttState and rttHistory) as they are not needed in the receiver.
- UI Adjustments:
  - Added display for OWD metrics: latest, max, min, and average.
- Signaling Data Handling:
  - In handleSignalingData, under "time_sync_request", OWD is calculated as t2 - t1 and tracked.
Unified Time Synchronization:
- Both fragments use a single time synchronization mechanism where:
  - Initiator sends time_sync_request with t1.
  - Receiver responds with time_sync_response containing t1, t2, and t3.
  - Initiator calculates RTT using t1, t2, t3, and t4.
  - Receiver calculates OWD as t2 - t1 upon handling the request.
UI Enhancements:
- Both fragments now display comprehensive metrics for RTT and OWD respectively, including latest, maximum, minimum, and average values.
- This provides users with a clear understanding of the network performance metrics in real-time.
Code Clean-Up:
- Removed unnecessary or redundant state variables to streamline the code.
- Ensured that all UI components are appropriately updated based on the new state variables.
Permissions Handling:
- Implemented a basic permissions request mechanism to ensure that necessary permissions (like camera and microphone) are granted before initializing video components.
Logging Enhancements:
- Added detailed logging statements to help in debugging and monitoring the flow of data and state changes.

Additional Recommendations:

Error Handling: Ensure that all potential exceptions, especially around network communication and media initialization, are properly handled to prevent application crashes.
UI Thread Safety: While using LaunchedEffect and lifecycleScope, ensure that all UI updates are performed on the main thread to prevent unexpected behavior.
Resource Management: Always release or dispose of resources like PeerConnection, SurfaceViewRenderer, and EglBase in the onDestroyView method to prevent memory leaks.
UI Enhancements: Consider adding graphical representations (like charts) for RTT and OWD metrics to provide a more intuitive visualization for users.

By implementing these changes, your application will effectively calculate and display both RTT and OWD using a unified time synchronization request, providing users with valuable insights into the network performance during video communication sessions.

سؤال

用中文回答

الفكرة

连接服务器和管理延迟

正在考虑使用Socket.IO连接信令服务器，管理WebRTC PeerConnections以收集RTT和OWD统计数据。发起端和接收端显示不同的延迟值。

الإجابة

当然可以！以下是修改后的 VideoInitiatorFragment 和 VideoReceiverFragment 类代码。这些修改确保使用同一个时间同步请求来计算单向时延（OWD）和往返时延（RTT），并在界面上展示相应的统计数据。发起端（VideoInitiatorFragment）将显示 RTT 的最新值、最大值、最小值和平均值；接收端（VideoReceiverFragment）将显示 OWD 的最新值、最大值、最小值和平均值。

主要修改点：

统一时间同步：两个片段使用同一个时间同步请求来计算 RTT 和 OWD。
指标跟踪：
- 发起端跟踪 RTT 指标。
- 接收端跟踪 OWD 指标。
UI 更新：
- 发起端展示 RTT（最新、最大、最小和平均）。
- 接收端展示 OWD（最新、最大、最小和平均）。

修改后的 `VideoInitiatorFragment`：

class VideoInitiatorFragment : Fragment() {

    // 类成员变量
    private lateinit var socket: Socket
    private var localPeer: PeerConnection? = null
    private var localView: SurfaceViewRenderer? = null
    private var localEglBase: EglBase? = null
    private val pendingIceCandidates = mutableListOf<IceCandidate>()
    private var currentRoom: String? = null
    private lateinit var signalingServerUrl: String
    private lateinit var stunUrl: String
    private lateinit var turnUrl: String
    private lateinit var turnUsername: String
    private lateinit var turnPassword: String

    private val TAG: String = "WebRTC-Initiator"

    // RTT 的状态变量
    private val rttState = mutableLongStateOf(0L)
    private val rttHistory = mutableStateListOf<Long>()

    // 统计任务
    private var statsJob: Job? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // 从参数中获取数据
        currentRoom = arguments?.getString("room") ?: "default-room"
        signalingServerUrl = arguments?.getString("signalingServerUrl") ?: "https://wstszx.us.kg"
        stunUrl = arguments?.getString("stunUrl") ?: "stun:stun.wstszx.us.kg:3478"
        turnUrl = arguments?.getString("turnUrl") ?: "turn:turn.wstszx.us.kg:5349"
        turnUsername = arguments?.getString("turnUsername") ?: "wstszx"
        turnPassword = arguments?.getString("turnPassword") ?: "930379"

        Log.d(
            TAG,
            "onCreate: Role = Initiator, Room = $currentRoom, Signaling Server = $signalingServerUrl, STUN URL = $stunUrl, TURN URL = $turnUrl"
        )
    }

    private val requestPermissionsLauncher =
        registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
            permissions.entries.forEach { (permission, isGranted) ->
                if (isGranted) {
                    Toast.makeText(requireContext(), "$permission 权限已授予", Toast.LENGTH_SHORT).show()
                } else {
                    Toast.makeText(requireContext(), "$permission 权限被拒绝", Toast.LENGTH_SHORT).show()
                }
            }
            onPermissionsChecked()
        }

    override fun onCreateView(
        inflater: android.view.LayoutInflater,
        container: android.view.ViewGroup?,
        savedInstanceState: Bundle?
    ): android.view.View {
        return ComposeView(requireContext()).apply {
            setContent {
                WebRTCComposeLayout()
            }
        }
    }

    @Composable
    fun WebRTCComposeLayout() {
        val context = LocalContext.current
        lateinit var peerConnectionFactory: PeerConnectionFactory
        var localVideoTrack: VideoTrack? by remember { mutableStateOf(null) }

        Surface(color = Color.Black) {
            Column(modifier = Modifier.fillMaxSize()) {

                // 可以在这里添加其他 UI 组件

                Spacer(modifier = Modifier.height(8.dp))

                // 展示 RTT 指标
                Column(modifier = Modifier.padding(horizontal = 16.dp)) {
                    Text(
                        text = "往返时延 (RTT) 最新: ${rttState.longValue} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "RTT 最大: ${rttHistory.maxOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "RTT 最小: ${rttHistory.minOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    val averageRtt = if (rttHistory.isNotEmpty()) rttHistory.average().toLong() else 0L
                    Text(
                        text = "RTT 平均: $averageRtt ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 8.dp)
                    )
                }

                // 可以在这里添加其他 UI 组件

            }

            LaunchedEffect(Unit) {
                val options = PeerConnectionFactory.InitializationOptions.builder(context)
                    .createInitializationOptions()
                PeerConnectionFactory.initialize(options)

                val encoderFactory = DefaultVideoEncoderFactory(
                    localEglBase!!.eglBaseContext, true, true
                )

                val decoderFactory = DefaultVideoDecoderFactory(localEglBase!!.eglBaseContext)

                peerConnectionFactory = PeerConnectionFactory.builder()
                    .setVideoEncoderFactory(encoderFactory)
                    .setVideoDecoderFactory(decoderFactory)
                    .createPeerConnectionFactory()

                initLocalVideo(context, localView, peerConnectionFactory, localEglBase!!) {
                    localVideoTrack = it
                }

                createPeerConnection(
                    context,
                    peerConnectionFactory,
                    localVideoTrack
                ) {
                    localPeer = it
                    startStatsCollection() // 开始收集统计数据
                }

                initializeSocketIO()

                requestPermissionsIfNeeded()
                startTimeSync()
            }
        }
    }

    private fun startTimeSync(intervalMs: Long = 5000L) {
        viewLifecycleOwner.lifecycleScope.launch {
            while (isActive) {
                delay(intervalMs) // 每 5 秒同步一次
                requestTimeSync()
            }
        }
    }

    private fun startStatsCollection() {
        statsJob = viewLifecycleOwner.lifecycleScope.launch {
            while (isActive) {
                delay(1000) // 每秒收集一次统计数据
                localPeer?.getStats { report ->
                    parseStatsReport(report)
                } ?: Log.e(TAG, "获取统计数据失败: localPeer 为 null.")
            }
        }
    }

    private fun parseStatsReport(report: RTCStatsReport) {
        // 如果需要，可以在这里实现统计数据的解析
    }

    private fun initializeSocketIO() {
        val protocol = if (signalingServerUrl.startsWith("https")) "https" else "http"
        val socketUrl = signalingServerUrl

        val options = IO.Options().apply {
            transports = arrayOf("websocket")
            secure = protocol == "https"
            path = "/socket.io/"
        }

        try {
            socket = IO.socket(socketUrl, options)

            socket.on(Socket.EVENT_CONNECT) {
                Log.d(TAG, "Socket 已连接")
                socket.emit("join", currentRoom)
                Log.d(TAG, "加入房间: $currentRoom")
            }

            socket.on(Socket.EVENT_CONNECT_ERROR) { args ->
                if (args.isNotEmpty()) {
                    val error = args[0]
                    Log.e(TAG, "Socket 连接错误: $error")
                }
            }

            socket.on(Socket.EVENT_DISCONNECT) { args ->
                if (args.isNotEmpty()) {
                    val reason = args[0]
                    Log.d(TAG, "Socket 已断开: $reason")
                }
            }

            socket.on("signal") { args ->
                Log.d(TAG, "接收到信令: ${args[0]}")
                if (args.isNotEmpty() && args[0] is JSONObject) {
                    val data = args[0] as JSONObject
                    handleSignalingData(data)
                }
            }

            socket.connect()
            Log.d(TAG, "正在连接到 Socket: $socketUrl...")
        } catch (e: Exception) {
            Log.e(TAG, "连接 Socket 时出错: ${e.message}")
        }
    }

    private fun requestPermissionsIfNeeded() {
        // 请求必要的权限
        val permissions = arrayOf(
            Manifest.permission.CAMERA,
            Manifest.permission.RECORD_AUDIO
        )
        requestPermissionsLauncher.launch(permissions)
    }

    private fun onPermissionsChecked() {
        Toast.makeText(requireContext(), "所有必要权限已被授予", Toast.LENGTH_SHORT).show()
        // 继续初始化视频或其他组件
    }

    private fun initLocalVideo(
        context: Context,
        localView: SurfaceViewRenderer?,
        peerConnectionFactory: PeerConnectionFactory,
        eglBase: EglBase,
        onLocalVideoTrack: (VideoTrack) -> Unit
    ) {
        // 初始化本地视频的实现
    }

    private fun createCameraCapturer(context: Context): CameraVideoCapturer {
        // 创建摄像头捕获器的实现
        val cameraEnumerator = Camera2Enumerator(context)
        val deviceNames = cameraEnumerator.deviceNames
        for (deviceName in deviceNames) {
            if (cameraEnumerator.isFrontFacing(deviceName)) {
                return cameraEnumerator.createCapturer(deviceName, null)!!
            }
        }
        throw RuntimeException("未找到前置摄像头。")
    }

    private fun createPeerConnection(
        context: Context,
        peerConnectionFactory: PeerConnectionFactory,
        localVideoTrack: VideoTrack?,
        onLocalPeerCreated: (PeerConnection) -> Unit
    ) {
        // 创建 PeerConnection 的实现
    }

    private fun createAnswer(peerConnection: PeerConnection, onAnswerCreated: (String) -> Unit) {
        Log.d(TAG, "正在创建应答...")
        // 创建应答的实现
    }

    private fun handleSignalingData(data: JSONObject) {
        Log.d(TAG, "处理信令数据: $data")
        when (data.getString("type")) {
            "offer" -> {
                Log.d(TAG, "接收到 offer")
                val sdp = SessionDescription(
                    SessionDescription.Type.OFFER,
                    data.getJSONObject("sdp").getString("sdp")
                )
                localPeer?.setRemoteDescription(object : SdpObserver {
                    override fun onSetSuccess() {
                        Log.d(TAG, "设置远程描述（offer）成功")
                        createAnswer(localPeer!!) { answer ->
                            val signalData = JSONObject().apply {
                                put("type", "answer")
                                put("sdp", JSONObject().put("sdp", answer))
                                put("room", currentRoom)
                            }

                            socket.emit("signal", signalData)
                            Log.d(TAG, "发送应答 SDP。")

                            pendingIceCandidates.forEach { candidate ->
                                localPeer?.addIceCandidate(candidate)
                            }
                            pendingIceCandidates.clear()
                        }
                    }

                    override fun onSetFailure(error: String?) {
                        Log.e(TAG, "设置远程描述（offer）错误: $error")
                    }

                    override fun onCreateSuccess(p0: SessionDescription?) {}
                    override fun onCreateFailure(p0: String?) {}
                }, sdp)
            }

            "answer" -> {
                Log.d(TAG, "接收到 answer")
                val sdp = SessionDescription(
                    SessionDescription.Type.ANSWER,
                    data.getJSONObject("sdp").getString("sdp")
                )
                localPeer?.setRemoteDescription(object : SdpObserver {
                    override fun onSetSuccess() {
                        pendingIceCandidates.forEach { candidate ->
                            localPeer?.addIceCandidate(candidate)
                        }
                        pendingIceCandidates.clear()
                        Log.d(TAG, "设置远程描述（answer）成功")
                    }

                    override fun onSetFailure(error: String?) {
                        Log.e(TAG, "设置远程描述（answer）错误: $error")
                    }

                    override fun onCreateSuccess(p0: SessionDescription?) {}
                    override fun onCreateFailure(p0: String?) {}
                }, sdp)
            }

            "ice" -> {
                Log.d(TAG, "接收到 ICE candidate")
                val candidateData = data.getJSONObject("candidate")
                val candidate = IceCandidate(
                    candidateData.getString("sdpMid"),
                    candidateData.getInt("sdpMLineIndex"),
                    candidateData.getString("candidate")
                )

                if (localPeer?.remoteDescription != null) {
                    localPeer?.addIceCandidate(candidate)
                } else {
                    pendingIceCandidates.add(candidate)
                }
            }

            "time_sync_response" -> {
                Log.d(TAG, "接收到 time_sync_response")
                val t1 = data.getLong("t1")
                val t2 = data.getLong("t2")
                val t3 = data.getLong("t3")
                val t4 = System.currentTimeMillis()

                // 计算 RTT
                val rtt = t4 - t1 - (t3 - t2)

                Log.d(TAG, "时间同步: RTT=$rtt ms")

                viewLifecycleOwner.lifecycleScope.launch {
                    // 更新 RTT 状态
                    rttState.longValue = rtt

                    // 更新 RTT 历史记录
                    rttHistory.add(rtt)
                    if (rttHistory.size > 60) {
                        rttHistory.removeAt(0)
                    }

                    // 计算 RTT 的最大、最小和平均值
                    val maxRtt = rttHistory.maxOrNull() ?: 0L
                    val minRtt = rttHistory.minOrNull() ?: 0L
                    val averageRtt = if (rttHistory.isNotEmpty()) {
                        rttHistory.average().toLong()
                    } else {
                        0L
                    }

                    Log.d(TAG, "RTT - 最新: $rtt ms, 最大: $maxRtt ms, 最小: $minRtt ms, 平均: $averageRtt ms")
                }
            }

            else -> {
                Log.e(TAG, "未知的信令类型: ${data.getString("type")}")
            }
        }
    }

    private fun requestTimeSync() {
        val t1 = System.currentTimeMillis()
        val syncRequest = JSONObject().apply {
            put("type", "time_sync_request")
            put("room", currentRoom)
            put("t1", t1)
        }
        socket.emit("signal", syncRequest)
        Log.d(TAG, "发送时间同步请求，t1: $t1")
    }

    override fun onDestroyView() {
        super.onDestroyView()
        statsJob?.cancel()
        socket.disconnect()
        localPeer?.dispose()
        localView?.release()
        localEglBase?.release()
    }
}

修改后的 `VideoReceiverFragment`：

class VideoReceiverFragment : Fragment() {

    companion object {
        fun newInstance(
            room: String,
            stunUrl: String,
            turnUrl: String,
            turnUsername: String,
            turnPassword: String,
            signalingServerUrl: String
        ): VideoReceiverFragment {
            val fragment = VideoReceiverFragment()
            val args = Bundle().apply {
                putString("room", room)
                putString("stunUrl", stunUrl)
                putString("turnUrl", turnUrl)
                putString("turnUsername", turnUsername)
                putString("turnPassword", turnPassword)
                putString("signalingServerUrl", signalingServerUrl)
            }
            fragment.arguments = args
            return fragment
        }
    }

    // 类成员变量
    private lateinit var socket: Socket
    private var localPeer: PeerConnection? = null
    private var remoteView: SurfaceViewRenderer? = null
    private var remoteEglBase: EglBase? = null
    private val pendingIceCandidates = mutableListOf<IceCandidate>()
    private var currentRoom: String? = null
    private lateinit var signalingServerUrl: String
    private lateinit var stunUrl: String
    private lateinit var turnUrl: String
    private lateinit var turnUsername: String
    private lateinit var turnPassword: String
    private val TAG: String = "WebRTC-Receiver"

    // OWD 的状态变量
    private val owdState = mutableLongStateOf(0L)
    private val owdHistory = mutableStateListOf<Long>()

    private val frameRateState = mutableDoubleStateOf(0.0)
    private val bitrateState = mutableLongStateOf(0L)
    private val stutteringState = mutableStateOf(false)

    private val frameRateLowState = mutableStateOf(false)
    private val packetLossHighState = mutableStateOf(false)
    private val packetLossState = mutableDoubleStateOf(0.0)

    private val frameRateHistory = mutableStateListOf<Float>()
    private val bitrateHistory = mutableStateListOf<Long>()
    private var timeSyncJob: Job? = null

    // 历史变量
    private var prevFramesDecoded = 0.0
    private var prevBytesReceived = 0.0
    private var prevFramesReceived = 0.0
    private var prevFramesDropped = 0.0
    private var prevTimestamp = 0.0
    private var timeOffset: Long = 0
    private var t1: Long = 0

    private var statsJob: Job? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // 从参数中获取数据
        currentRoom = arguments?.getString("room") ?: "default-room"
        signalingServerUrl = arguments?.getString("signalingServerUrl") ?: "https://wstszx.us.kg"
        stunUrl = arguments?.getString("stunUrl") ?: "stun:stun.wstszx.us.kg:3478"
        turnUrl = arguments?.getString("turnUrl") ?: "turn:turn.wstszx.us.kg:5349"
        turnUsername = arguments?.getString("turnUsername") ?: "wstszx"
        turnPassword = arguments?.getString("turnPassword") ?: "930379"

        Log.d(
            TAG,
            "onCreate: Role = Receiver, Room = $currentRoom, Signaling Server = $signalingServerUrl, STUN URL = $stunUrl, TURN URL = $turnUrl"
        )
    }

    private val requestPermissionsLauncher =
        registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
            permissions.entries.forEach { (permission, isGranted) ->
                if (isGranted) {
                    Toast.makeText(requireContext(), "$permission 权限已授予", Toast.LENGTH_SHORT).show()
                } else {
                    Toast.makeText(requireContext(), "$permission 权限被拒绝", Toast.LENGTH_SHORT).show()
                }
            }
            onPermissionsChecked()
        }

    override fun onCreateView(
        inflater: android.view.LayoutInflater,
        container: android.view.ViewGroup?,
        savedInstanceState: Bundle?
    ): android.view.View {
        return ComposeView(requireContext()).apply {
            setContent {
                WebRTCComposeLayout()
            }
        }
    }

    @Composable
    fun WebRTCComposeLayout() {
        val context = LocalContext.current
        lateinit var peerConnectionFactory: PeerConnectionFactory

        Surface(color = Color.Black) {
            Column(modifier = Modifier.fillMaxSize()) {

                // 远程视频视图可以在这里添加

                Spacer(modifier = Modifier.height(8.dp))

                // 展示 OWD 指标
                Column(modifier = Modifier.padding(horizontal = 16.dp)) {
                    Text(
                        text = "单向时延 (OWD) 最新: ${owdState.longValue} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "OWD 最大: ${owdHistory.maxOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "OWD 最小: ${owdHistory.minOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    val averageOwd = if (owdHistory.isNotEmpty()) owdHistory.average().toLong() else 0L
                    Text(
                        text = "OWD 平均: $averageOwd ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 8.dp)
                    )
                }

                // 现有的帧率、码率等 UI 组件

                Spacer(modifier = Modifier.height(8.dp))

                // 帧率部分
                Column(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 8.dp)
                ) {
                    // 中文的帧率文本
                    Text(
                        text = "帧率: ${frameRateState.doubleValue.roundToInt()} fps",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Log.d(
                        TAG,
                        "UI - 帧率: ${frameRateState.doubleValue} fps, 码率: ${bitrateState.longValue / 1000} kbps"
                    )

                    // 帧率的折线图
                    LineChart(
                        data = frameRateHistory,
                        modifier = Modifier
                            .height(200.dp)
                            .fillMaxWidth()
                            .padding(vertical = 8.dp),
                        lineColor = Color.Green,
                        backgroundColor = Color.Black,
                        yAxisLabel = "帧率 (fps)",
                        xAxisLabel = "时间 (秒)"
                    )
                }

                Spacer(modifier = Modifier.height(8.dp))

                // 码率部分
                Column(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 16.dp)
                ) {
                    // 中文的码率文本
                    Text(
                        text = "码率: ${bitrateState.longValue / 1000} kbps",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )

                    // 码率的折线图
                    LineChart(
                        data = bitrateHistory.map { it / 1000f }, // 转换为 kbps
                        modifier = Modifier
                            .height(200.dp)
                            .fillMaxWidth()
                            .padding(vertical = 8.dp),
                        lineColor = Color.Blue,
                        backgroundColor = Color.Black,
                        yAxisLabel = "码率 (kbps)",
                        xAxisLabel = "时间 (秒)"
                    )
                }

                Spacer(modifier = Modifier.height(16.dp))

                // 卡顿指示器
                Row(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 16.dp),
                    verticalAlignment = Alignment.CenterVertically
                ) {
                    if (stutteringState.value) {
                        Icon(
                            imageVector = Icons.Default.Warning,
                            contentDescription = "卡顿警告",
                            tint = Color.Red,
                            modifier = Modifier.size(24.dp)
                        )
                        Spacer(modifier = Modifier.width(8.dp))
                        Column {
                            Text(
                                text = "视频播放出现卡顿",
                                color = Color.Red,
                                style = MaterialTheme.typography.bodyMedium
                            )
                            // 显示具体的异常指标
                            if (frameRateLowState.value) {
                                Text(
                                    text = "帧率过低: ${frameRateState.doubleValue.roundToInt()} fps",
                                    color = Color.Red,
                                    style = MaterialTheme.typography.bodySmall
                                )
                            }
                            if (packetLossHighState.value) {
                                Text(
                                    text = "包丢失率过高: ${packetLossState.doubleValue.roundToInt()}%",
                                    color = Color.Red,
                                    style = MaterialTheme.typography.bodySmall
                                )
                            }
                        }
                    } else {
                        Icon(
                            imageVector = Icons.Default.CheckCircle,
                            contentDescription = "正常",
                            tint = Color.Green,
                            modifier = Modifier.size(24.dp)
                        )
                        Spacer(modifier = Modifier.width(8.dp))
                        Text(
                            text = "视频播放正常",
                            color = Color.Green,
                            style = MaterialTheme.typography.bodyMedium
                        )
                    }
                }
            }

            LaunchedEffect(Unit) {
                val options = PeerConnectionFactory.InitializationOptions.builder(context)
                    .createInitializationOptions()
                PeerConnectionFactory.initialize(options)

                val encoderFactory = DefaultVideoEncoderFactory(
                    localEglBase!!.eglBaseContext, true, true
                )

                val decoderFactory = DefaultVideoDecoderFactory(remoteEglBase!!.eglBaseContext)

                peerConnectionFactory = PeerConnectionFactory.builder()
                    .setVideoEncoderFactory(encoderFactory)
                    .setVideoDecoderFactory(decoderFactory)
                    .createPeerConnectionFactory()

                createPeerConnection(
                    context,
                    peerConnectionFactory,
                    remoteView!!
                ) {
                    localPeer = it
                }

                initializeSocketIO()

                requestPermissionsIfNeeded()
            }
        }
    }

    /**
     * 增强的折线图 Composable，带坐标轴和标签
     * 使用直线连接每个点
     */
    @Composable
    fun LineChart(
        data: List<Float>,
        modifier: Modifier = Modifier,
        lineColor: Color = Color.Green,
        backgroundColor: Color = Color.Black,
        yAxisLabel: String = "",
        xAxisLabel: String = "",
        minYValue: Float? = null,
        maxYValue: Float? = null
    ) {
        // 使用 Canvas 绘制折线图，或使用任何兼容 Compose 的图表库
    }

    private fun initializeSocketIO() {
        val protocol = if (signalingServerUrl.startsWith("https")) "https" else "http"
        val socketUrl = signalingServerUrl

        val options = IO.Options().apply {
            transports = arrayOf("websocket")
            secure = protocol == "https"
            path = "/socket.io/"
        }

        try {
            socket = IO.socket(socketUrl, options)

            socket.on(Socket.EVENT_CONNECT) {
                Log.d(TAG, "Socket 已连接")
                socket.emit("join", currentRoom)
                Log.d(TAG, "加入房间: $currentRoom")
                initiateCall()
            }

            socket.on(Socket.EVENT_CONNECT_ERROR) { args ->
                if (args.isNotEmpty()) {
                    val error = args[0]
                    Log.e(TAG, "Socket 连接错误: $error")
                }
            }

            socket.on(Socket.EVENT_DISCONNECT) { args ->
                if (args.isNotEmpty()) {
                    val reason = args[0]
                    Log.d(TAG, "Socket 已断开: $reason")
                }
            }

            socket.on("signal") { args ->
                Log.d(TAG, "接收到信令: ${args[0]}")
                if (args.isNotEmpty() && args[0] is JSONObject) {
                    val data = args[0] as JSONObject
                    handleSignalingData(data)
                }
            }

            socket.connect()
            Log.d(TAG, "正在连接到 Socket: $socketUrl...")
        } catch (e: Exception) {
            Log.e(TAG, "连接 Socket 时出错: ${e.message}")
        }
    }

    private fun requestPermissionsIfNeeded() {
        // 请求必要的权限
        val permissions = arrayOf(
            Manifest.permission.CAMERA,
            Manifest.permission.RECORD_AUDIO
        )
        requestPermissionsLauncher.launch(permissions)
    }

    private fun onPermissionsChecked() {
        Toast.makeText(requireContext(), "所有必要的权限已被授予", Toast.LENGTH_SHORT).show()
        // 继续初始化视频或其他组件
    }

    private fun createPeerConnection(
        context: Context,
        peerConnectionFactory: PeerConnectionFactory,
        remoteView: SurfaceViewRenderer,
        onLocalPeerCreated: (PeerConnection) -> Unit
    ) {
        // 创建 PeerConnection 的实现
    }

    private fun initiateCall() {
        // 发起呼叫的实现，例如创建 offer
    }

    private fun handleSignalingData(data: JSONObject) {
        Log.d(TAG, "处理信令数据: $data")
        when (data.getString("type")) {

            "answer" -> {
                Log.d(TAG, "接收到 answer")
                val sdp = SessionDescription(
                    SessionDescription.Type.ANSWER,
                    data.getJSONObject("sdp").getString("sdp")
                )

                localPeer?.setRemoteDescription(object : SdpObserver {
                    override fun onSetSuccess() {
                        pendingIceCandidates.forEach { candidate ->
                            localPeer?.addIceCandidate(candidate)
                        }

                        pendingIceCandidates.clear()

                        Log.d(TAG, "设置远程描述（answer）成功")
                    }

                    override fun onSetFailure(error: String?) {
                        Log.e(TAG, "设置远程描述（answer）错误: $error")
                    }

                    override fun onCreateSuccess(p0: SessionDescription?) {}
                    override fun onCreateFailure(p0: String?) {}
                }, sdp)
            }

            "ice" -> {
                Log.d(TAG, "接收到 ICE candidate")
                val candidateData = data.getJSONObject("candidate")
                val candidate = IceCandidate(
                    candidateData.getString("sdpMid"),
                    candidateData.getInt("sdpMLineIndex"),
                    candidateData.getString("candidate")
                )

                if (localPeer?.remoteDescription != null) {
                    localPeer?.addIceCandidate(candidate)
                } else {
                    pendingIceCandidates.add(candidate)
                }
            }

            "time_sync_request" -> {
                val t1 = data.getLong("t1")
                val t2 = System.currentTimeMillis()
                val t3 = System.currentTimeMillis()
                val syncResponse = JSONObject().apply {
                    put("type", "time_sync_response")
                    put("t1", t1)
                    put("t2", t2)
                    put("t3", t3)
                    put("room", currentRoom)
                }
                socket.emit("signal", syncResponse)
                Log.d(TAG, "回复 time_sync_request: t1=$t1, t2=$t2, t3=$t3")

                // 计算 OWD
                val owd = t2 - t1
                Log.d(TAG, "时间同步: OWD=$owd ms")

                viewLifecycleOwner.lifecycleScope.launch {
                    // 更新 OWD 状态
                    owdState.longValue = owd

                    // 更新 OWD 历史记录
                    owdHistory.add(owd)
                    if (owdHistory.size > 60) {
                        owdHistory.removeAt(0)
                    }

                    // 计算 OWD 的最大、最小和平均值
                    val maxOwd = owdHistory.maxOrNull() ?: 0L
                    val minOwd = owdHistory.minOrNull() ?: 0L
                    val averageOwd = if (owdHistory.isNotEmpty()) {
                        owdHistory.average().toLong()
                    } else {
                        0L
                    }

                    Log.d(TAG, "OWD - 最新: $owd ms, 最大: $maxOwd ms, 最小: $minOwd ms, 平均: $averageOwd ms")
                }
            }

            else -> {
                Log.e(TAG, "未知的信令类型: ${data.getString("type")}")
            }
        }
    }

    private fun startStatsCollection() {
        Log.d(TAG, "开始收集统计数据...")
        statsJob = viewLifecycleOwner.lifecycleScope.launch {
            while (isActive) {
                delay(1000) // 每秒收集一次统计数据
                Log.d(TAG, "收集统计数据...")
                localPeer?.getStats { report ->
                    Log.d(TAG, "已获取统计报告。")
                    parseStatsReport(report)
                } ?: Log.e(TAG, "获取统计数据失败: localPeer 为 null.")
            }
        }
    }

    private fun parseStatsReport(report: RTCStatsReport) {
        Log.d(TAG, "接收到 RTCStatsReport: $report")
        for (stats in report.statsMap.values) {
            if (stats.type == "inbound-rtp") {
                val kind = stats.members["kind"] as? String
                if (kind == "video") {
                    val framesDecoded = (stats.members["framesDecoded"] as? Number)?.toDouble() ?: 0.0
                    val framesReceived = (stats.members["framesReceived"] as? Number)?.toDouble() ?: 0.0
                    val framesDropped = (stats.members["framesDropped"] as? Number)?.toDouble() ?: 0.0
                    val bytesReceived = (stats.members["bytesReceived"] as? Number)?.toDouble() ?: 0.0
                    val packetsLost = (stats.members["packetsLost"] as? Number)?.toDouble() ?: 0.0
                    val packetsReceived = (stats.members["packetsReceived"] as? Number)?.toDouble() ?: 1.0 // 避免除零
                    val packetLossFraction = packetsLost / (packetsLost + packetsReceived)
                    val timestamp = stats.timestampUs / 1_000_000.0 // 转换为秒

                    Log.d(
                        TAG,
                        "统计数据 - 解码帧数: $framesDecoded, 接收帧数: $framesReceived, 丢弃帧数: $framesDropped, 接收字节数: $bytesReceived, 丢包率: $packetLossFraction, 时间戳: $timestamp"
                    )

                    if (prevTimestamp != 0.0) {
                        val timeElapsed = timestamp - prevTimestamp
                        val framesDelta = framesDecoded - prevFramesDecoded
                        val bytesDelta = bytesReceived - prevBytesReceived
                        val framesReceivedDelta = framesReceived - prevFramesReceived
                        val framesDroppedDelta = framesDropped - prevFramesDropped

                        val frameRate = if (timeElapsed > 0) framesDelta / timeElapsed else 0.0
                        val bitrate = if (timeElapsed > 0) (bytesDelta * 8) / timeElapsed else 0.0 // 比特每秒
                        val packetLoss = packetLossFraction * 100 // 转换为百分比

                        Log.d(TAG, "计算的帧率: $frameRate fps, 码率: $bitrate bps, 丢包率: $packetLoss%")

                        // 根据阈值判断是否卡顿
                        val isStuttering = frameRate < 24 || packetLoss > 5.0 // 阈值可调整

                        // 更新状态
                        viewLifecycleOwner.lifecycleScope.launch {
                            frameRateState.doubleValue = frameRate
                            bitrateState.longValue = bitrate.toLong()
                            // 更新卡顿状态
                            stutteringState.value = isStuttering
                            // 更新具体卡顿原因
                            frameRateLowState.value = frameRate < 24
                            packetLossHighState.value = packetLoss > 5.0
                            packetLossState.doubleValue = packetLoss

                            // 更新历史记录
                            frameRateHistory.add(frameRate.toFloat())
                            if (frameRateHistory.size > 60) {
                                frameRateHistory.removeAt(0)
                            }

                            bitrateHistory.add(bitrate.toLong())
                            if (bitrateHistory.size > 60) {
                                bitrateHistory.removeAt(0)
                            }

                            Log.d(
                                TAG,
                                "更新的帧率: ${frameRateState.doubleValue} fps, 码率: ${bitrateState.longValue / 1000} kbps, 卡顿: $isStuttering"
                            )
                        }
                    }

                    // 更新之前的值
                    prevFramesDecoded = framesDecoded
                    prevBytesReceived = bytesReceived
                    prevFramesReceived = framesReceived
                    prevFramesDropped = framesDropped
                    prevTimestamp = timestamp
                }
            }
        }
    }

    override fun onDestroyView() {
        super.onDestroyView()
        statsJob?.cancel()
        socket.disconnect()
        localPeer?.dispose()
        remoteView?.release()
        remoteEglBase?.release()
        timeSyncJob?.cancel()
    }
}

说明：

移除发起端的 OWD 跟踪：
- 移除变量：
  - private val owdState = mutableLongStateOf(0L)
  - private val owdHistory = mutableStateListOf<Long>()
- UI 调整：
  - 从发起端的 UI 中移除了 OWD 的展示。
  - 添加了 RTT 指标的展示，包括最新值、最大值、最小值和平均值。
- 信令数据处理：
  - 在 handleSignalingData 方法中，针对 "time_sync_response" 类型，仅计算和跟踪 RTT。
接收端添加 OWD 跟踪：
- 添加变量：
  - private val owdState = mutableLongStateOf(0L)
  - private val owdHistory = mutableStateListOf<Long>()
- 移除 RTT 跟踪：
  - 移除了与 RTT 相关的变量（如 rttState 和 rttHistory），因为接收端只需要跟踪 OWD。
- UI 调整：
  - 添加了 OWD 指标的展示，包括最新值、最大值、最小值和平均值。
- 信令数据处理：
  - 在 handleSignalingData 方法中，针对 "time_sync_request" 类型，计算 OWD 为 t2 - t1 并进行跟踪。
统一时间同步：
- 两个片段使用同一个时间同步机制：
  - 发起端发送 time_sync_request，包含 t1。
  - 接收端响应 time_sync_response，包含 t1、t2 和 t3。
  - 发起端利用 t1、t2、t3 和 t4（当前时间）计算 RTT。
  - 接收端在处理请求时计算 OWD 为 t2 - t1。
UI 增强：
- 两个片段现在都展示了 RTT 和 OWD 的综合指标，包括最新值、最大值、最小值和平均值。
- 这为用户提供了实时的网络性能洞察。
代码清理：
- 移除了不必要或冗余的状态变量，使代码更加简洁。
- 确保所有 UI 组件根据新的状态变量进行适当更新。
权限处理：
- 实现了基本的权限请求机制，确保在初始化视频组件之前授予必要的权限（如摄像头和麦克风权限）。
日志增强：
- 添加了详细的日志语句，帮助调试和监控数据流和状态变化。

其他建议：

错误处理：确保所有潜在的异常，尤其是网络通信和媒体初始化相关的异常，得到适当处理，以防止应用崩溃。
UI 线程安全：在使用 LaunchedEffect 和 lifecycleScope 时，确保所有 UI 更新都在主线程上执行，以防止出现意外行为。
资源管理：在 onDestroyView 方法中始终释放或处理资源，如 PeerConnection、SurfaceViewRenderer 和 EglBase，以防止内存泄漏。
UI 增强：考虑为 RTT 和 OWD 指标添加图形化表示（如图表），以提供更直观的可视化效果。

通过实施这些修改，您的应用将有效地使用统一的时间同步请求来计算和展示 RTT 和 OWD，向用户提供宝贵的网络性能见解，从而优化视频通信体验。

سؤال

目前单向时延的值是负数，这是什么原因，给我修复这个问题

الفكرة

解决负值问题

我正在调试一个使用WebRTC的Kotlin(Android)视频通信应用。我发现OWD（单向延迟）计算出负值，正在查找原因并提出修复建议。

分析时间同步

捕捉时间戳并计算往返时间。使用RTT和OWD衡量延迟，考虑钟差影响。

考虑时钟同步问题

要准确测量OWD，需要确保时钟同步。没有时钟同步，基础时间戳的OWD计算会不准确。

调整计算方法

我在思考如何通过调整计算OWD的方法，例如改为(t3 - t1) / 2或确保时钟同步，来改进性能。

探讨时序问题

通过RTT估算OWD，假设对称延迟。记录差异计算时钟偏移量，确保准确性。这样做的目的是确保精确估算。

调整影响

为了修正负Owd问题，需要避免使用绝对时间戳，考虑在发起方计算或在接收方修改计算。

测量时偏差

可以通过调整计算方法，确保正值的计算，进而推测时钟偏差。_北京赛车pk

使用接收器本地时间，发送响应时增加时延，初始时间接收方收到时间同步响应后计算RTT和Offset，避免负OWD。

调整OBD计算

为了处理负的ODD，需要调整OBD计算方式。我会计算时钟偏移量，然后发送给接收方，让对方通过计算实时调整时延。这样，系统会变得更精准。

الإجابة

出现单向时延（OWD）为负数的主要原因是发起端（Initiator）和接收端（Receiver）之间的时钟不同步。由于两端设备的系统时间可能存在差异，直接使用绝对时间戳进行计算会导致不准确甚至负数的结果。

原因分析

在当前实现中，接收端计算 OWD 的方式是 owd = t2 - t1，其中：

t1 是发起端发送 time_sync_request 的时间。
t2 是接收端接收到 time_sync_request 的时间。

由于发起端和接收端的系统时钟不同步，t2 - t1 可能会出现负数或不准确的结果。这是因为 t1 和 t2 分别基于各自独立的系统时钟，无法直接进行比较。

解决方案

为了准确计算 OWD，需要先同步发起端和接收端的时钟，或者通过计算时钟偏移量来调整时间戳。以下是实现时钟同步并正确计算 OWD 的步骤：

计算时钟偏移量：使用类似于 NTP（网络时间协议）的方法，通过交换时间戳来估算发起端和接收端的时钟偏移量。
调整 OWD 计算：使用计算出的时钟偏移量来调整接收端的时间戳，从而得到准确的 OWD。

实现步骤

1. 修改时间同步协议

在发起端和接收端之间交换更多的时间戳信息，以便计算时钟偏移量。

发起端（Initiator）发送 time_sync_request：

private fun requestTimeSync() {
    val t1 = System.currentTimeMillis()
    val syncRequest = JSONObject().apply {
        put("type", "time_sync_request")
        put("room", currentRoom)
        put("t1", t1)
    }
    socket.emit("signal", syncRequest)
    Log.d(TAG, "发送时间同步请求，t1: $t1")
}

接收端（Receiver）处理 time_sync_request 并发送 time_sync_response：

"时间同步请求" -> {
    val t1 = data.getLong("t1")
    val t2 = System.currentTimeMillis()
    val t3 = t2 // 假设处理时间为零，如果有处理延迟，可以记录实际处理完成时间
    val syncResponse = JSONObject().apply {
        put("type", "time_sync_response")
        put("t1", t1)
        put("t2", t2)
        put("t3", t3)
        put("room", currentRoom)
    }
    socket.emit("signal", syncResponse)
    Log.d(TAG, "回复 time_sync_request: t1=$t1, t2=$t2, t3=$t3")
}

发起端（Initiator）接收 time_sync_response 并计算 RTT 和时钟偏移量：

"time_sync_response" -> {
    val t1 = data.getLong("t1")
    val t2 = data.getLong("t2")
    val t3 = data.getLong("t3")
    val t4 = System.currentTimeMillis()

    // 计算 RTT
    val rtt = t4 - t1 - (t3 - t2)

    // 计算时钟偏移量
    val offset = ((t2 - t1) + (t3 - t4)) / 2

    Log.d(TAG, "时间同步: RTT=$rtt ms, 时钟偏移量=$offset ms")

    viewLifecycleOwner.lifecycleScope.launch {
        // 更新 RTT 状态
        rttState.longValue = rtt

        // 更新 RTT 历史记录
        rttHistory.add(rtt)
        if (rttHistory.size > 60) {
            rttHistory.removeAt(0)
        }

        // 计算 RTT 的最大、最小和平均值
        val maxRtt = rttHistory.maxOrNull() ?: 0L
        val minRtt = rttHistory.minOrNull() ?: 0L
        val averageRtt = if (rttHistory.isNotEmpty()) {
            rttHistory.average().toLong()
        } else {
            0L
        }

        Log.d(TAG, "RTT - 最新: $rtt ms, 最大: $maxRtt ms, 最小: $minRtt ms, 平均: $averageRtt ms")

        // 将时钟偏移量存储或发送给接收端以调整 OWD
        // 这里可以通过 socket.emit 发送偏移量给接收端，或使用其他机制
        sendClockOffset(offset)
    }
}

2. 发送时钟偏移量给接收端

发起端发送时钟偏移量：

在计算出时钟偏移量后，将其发送给接收端，以便接收端调整自己的时间戳。

private fun sendClockOffset(offset: Long) {
    val offsetData = JSONObject().apply {
        put("type", "clock_offset")
        put("offset", offset)
        put("room", currentRoom)
    }
    socket.emit("signal", offsetData)
    Log.d(TAG, "发送时钟偏移量: offset=$offset ms")
}

接收端接收并存储时钟偏移量：

在接收端，接收并存储时钟偏移量，用于调整 OWD 计算。

// 在 VideoReceiverFragment 中添加一个变量来存储时钟偏移量
private var clockOffset: Long = 0L

// 在 handleSignalingData 方法中处理 clock_offset
"clock_offset" -> {
    clockOffset = data.getLong("offset")
    Log.d(TAG, "接收到时钟偏移量: offset=$clockOffset ms")
}

3. 调整 OWD 的计算

使用存储的时钟偏移量来调整接收端的时间戳，从而得到准确的 OWD。

接收端计算 OWD：

修改接收端计算 OWD 的方式，考虑时钟偏移量。

"time_sync_request" -> {
    val t1 = data.getLong("t1")
    val t2 = System.currentTimeMillis()
    val t3 = t2 // 假设处理时间为零，如果有处理延迟，可以记录实际处理完成时间
    val syncResponse = JSONObject().apply {
        put("type", "time_sync_response")
        put("t1", t1)
        put("t2", t2)
        put("t3", t3)
        put("room", currentRoom)
    }
    socket.emit("signal", syncResponse)
    Log.d(TAG, "回复 time_sync_request: t1=$t1, t2=$t2, t3=$t3")

    // 计算 OWD，考虑时钟偏移量
    val adjustedT2 = t2 - clockOffset
    val owd = adjustedT2 - t1
    if (owd >= 0) {
        Log.d(TAG, "时间同步: OWD=$owd ms")
    } else {
        Log.e(TAG, "计算的 OWD 为负数: OWD=$owd ms，可能由于时钟偏移未同步或计算错误。")
    }

    viewLifecycleOwner.lifecycleScope.launch {
        // 更新 OWD 状态
        owdState.longValue = owd

        // 更新 OWD 历史记录
        owdHistory.add(owd)
        if (owdHistory.size > 60) {
            owdHistory.removeAt(0)
        }

        // 计算 OWD 的最大、最小和平均值
        val maxOwd = owdHistory.maxOrNull() ?: 0L
        val minOwd = owdHistory.minOrNull() ?: 0L
        val averageOwd = if (owdHistory.isNotEmpty()) owdHistory.average().toLong() else 0L

        Log.d(TAG, "OWD - 最新: $owd ms, 最大: $maxOwd ms, 最小: $minOwd ms, 平均: $averageOwd ms")
    }
}

完整的代码修正

以下是针对 VideoReceiverFragment 的完整修正代码，包含时钟偏移量的计算和 OWD 的调整：

class VideoReceiverFragment : Fragment() {

    companion object {
        fun newInstance(
            room: String,
            stunUrl: String,
            turnUrl: String,
            turnUsername: String,
            turnPassword: String,
            signalingServerUrl: String
        ): VideoReceiverFragment {
            val fragment = VideoReceiverFragment()
            val args = Bundle().apply {
                putString("room", room)
                putString("stunUrl", stunUrl)
                putString("turnUrl", turnUrl)
                putString("turnUsername", turnUsername)
                putString("turnPassword", turnPassword)
                putString("signalingServerUrl", signalingServerUrl)
            }
            fragment.arguments = args
            return fragment
        }
    }

    // 类成员变量
    private lateinit var socket: Socket
    private var localPeer: PeerConnection? = null
    private var remoteView: SurfaceViewRenderer? = null
    private var remoteEglBase: EglBase? = null
    private val pendingIceCandidates = mutableListOf<IceCandidate>()
    private var currentRoom: String? = null
    private lateinit var signalingServerUrl: String
    private lateinit var stunUrl: String
    private lateinit var turnUrl: String
    private lateinit var turnUsername: String
    private lateinit var turnPassword: String
    private val TAG: String = "WebRTC-Receiver"

    // OWD 的状态变量
    private val owdState = mutableLongStateOf(0L)
    private val owdHistory = mutableStateListOf<Long>()

    private val frameRateState = mutableDoubleStateOf(0.0)
    private val bitrateState = mutableLongStateOf(0L)
    private val stutteringState = mutableStateOf(false)

    private val frameRateLowState = mutableStateOf(false)
    private val packetLossHighState = mutableStateOf(false)
    private val packetLossState = mutableDoubleStateOf(0.0)

    private val frameRateHistory = mutableStateListOf<Float>()
    private val bitrateHistory = mutableStateListOf<Long>()
    private var timeSyncJob: Job? = null

    // 历史变量
    private var prevFramesDecoded = 0.0
    private var prevBytesReceived = 0.0
    private var prevFramesReceived = 0.0
    private var prevFramesDropped = 0.0
    private var prevTimestamp = 0.0
    private var timeOffset: Long = 0
    private var t1: Long = 0

    private var statsJob: Job? = null

    // 存储时钟偏移量
    private var clockOffset: Long = 0L

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // 从参数中获取数据
        currentRoom = arguments?.getString("room") ?: "default-room"
        signalingServerUrl = arguments?.getString("signalingServerUrl") ?: "https://wstszx.us.kg"
        stunUrl = arguments?.getString("stunUrl") ?: "stun:stun.wstszx.us.kg:3478"
        turnUrl = arguments?.getString("turnUrl") ?: "turn:turn.wstszx.us.kg:5349"
        turnUsername = arguments?.getString("turnUsername") ?: "wstszx"
        turnPassword = arguments?.getString("turnPassword") ?: "930379"

        Log.d(
            TAG,
            "onCreate: Role = Receiver, Room = $currentRoom, Signaling Server = $signalingServerUrl, STUN URL = $stunUrl, TURN URL = $turnUrl"
        )
    }

    private val requestPermissionsLauncher =
        registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
            permissions.entries.forEach { (permission, isGranted) ->
                if (isGranted) {
                    Toast.makeText(requireContext(), "$permission 权限已授予", Toast.LENGTH_SHORT).show()
                } else {
                    Toast.makeText(requireContext(), "$permission 权限被拒绝", Toast.LENGTH_SHORT).show()
                }
            }
            onPermissionsChecked()
        }

    override fun onCreateView(
        inflater: android.view.LayoutInflater,
        container: android.view.ViewGroup?,
        savedInstanceState: Bundle?
    ): android.view.View {
        return ComposeView(requireContext()).apply {
            setContent {
                WebRTCComposeLayout()
            }
        }
    }

    @Composable
    fun WebRTCComposeLayout() {
        val context = LocalContext.current
        lateinit var peerConnectionFactory: PeerConnectionFactory

        Surface(color = Color.Black) {
            Column(modifier = Modifier.fillMaxSize()) {

                // 远程视频视图可以在这里添加

                Spacer(modifier = Modifier.height(8.dp))

                // 展示 OWD 指标
                Column(modifier = Modifier.padding(horizontal = 16.dp)) {
                    Text(
                        text = "单向时延 (OWD) 最新: ${owdState.longValue} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "OWD 最大: ${owdHistory.maxOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Text(
                        text = "OWD 最小: ${owdHistory.minOrNull() ?: 0} ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    val averageOwd = if (owdHistory.isNotEmpty()) owdHistory.average().toLong() else 0L
                    Text(
                        text = "OWD 平均: $averageOwd ms",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 8.dp)
                    )
                }

                // 现有的帧率、码率等 UI 组件

                Spacer(modifier = Modifier.height(8.dp))

                // 帧率部分
                Column(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 8.dp)
                ) {
                    // 中文的帧率文本
                    Text(
                        text = "帧率: ${frameRateState.doubleValue.roundToInt()} fps",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )
                    Log.d(
                        TAG,
                        "UI - 帧率: ${frameRateState.doubleValue} fps, 码率: ${bitrateState.longValue / 1000} kbps"
                    )

                    // 帧率的折线图
                    LineChart(
                        data = frameRateHistory,
                        modifier = Modifier
                            .height(200.dp)
                            .fillMaxWidth()
                            .padding(vertical = 8.dp),
                        lineColor = Color.Green,
                        backgroundColor = Color.Black,
                        yAxisLabel = "帧率 (fps)",
                        xAxisLabel = "时间 (秒)"
                    )
                }

                Spacer(modifier = Modifier.height(8.dp))

                // 码率部分
                Column(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 16.dp)
                ) {
                    // 中文的码率文本
                    Text(
                        text = "码率: ${bitrateState.longValue / 1000} kbps",
                        color = Color.White,
                        style = MaterialTheme.typography.bodyMedium,
                        modifier = Modifier.padding(bottom = 4.dp)
                    )

                    // 码率的折线图
                    LineChart(
                        data = bitrateHistory.map { it / 1000f }, // 转换为 kbps
                        modifier = Modifier
                            .height(200.dp)
                            .fillMaxWidth()
                            .padding(vertical = 8.dp),
                        lineColor = Color.Blue,
                        backgroundColor = Color.Black,
                        yAxisLabel = "码率 (kbps)",
                        xAxisLabel = "时间 (秒)"
                    )
                }

                Spacer(modifier = Modifier.height(16.dp))

                // 卡顿指示器
                Row(
                    modifier = Modifier
                        .fillMaxWidth()
                        .padding(horizontal = 16.dp),
                    verticalAlignment = Alignment.CenterVertically
                ) {
                    if (stutteringState.value) {
                        Icon(
                            imageVector = Icons.Default.Warning,
                            contentDescription = "卡顿警告",
                            tint = Color.Red,
                            modifier = Modifier.size(24.dp)
                        )
                        Spacer(modifier = Modifier.width(8.dp))
                        Column {
                            Text(
                                text = "视频播放出现卡顿",
                                color = Color.Red,
                                style = MaterialTheme.typography.bodyMedium
                            )
                            // 显示具体的异常指标
                            if (frameRateLowState.value) {
                                Text(
                                    text = "帧率过低: ${frameRateState.doubleValue.roundToInt()} fps",
                                    color = Color.Red,
                                    style = MaterialTheme.typography.bodySmall
                                )
                            }
                            if (packetLossHighState.value) {
                                Text(
                                    text = "包丢失率过高: ${packetLossState.doubleValue.roundToInt()}%",
                                    color = Color.Red,
                                    style = MaterialTheme.typography.bodySmall
                                )
                            }
                        }
                    } else {
                        Icon(
                            imageVector = Icons.Default.CheckCircle,
                            contentDescription = "正常",
                            tint = Color.Green,
                            modifier = Modifier.size(24.dp)
                        )
                        Spacer(modifier = Modifier.width(8.dp))
                        Text(
                            text = "视频播放正常",
                            color = Color.Green,
                            style = MaterialTheme.typography.bodyMedium
                        )
                    }
                }
            }

            LaunchedEffect(Unit) {
                val options = PeerConnectionFactory.InitializationOptions.builder(context)
                    .createInitializationOptions()
                PeerConnectionFactory.initialize(options)

                val encoderFactory = DefaultVideoEncoderFactory(
                    remoteEglBase!!.eglBaseContext, true, true
                )

                val decoderFactory = DefaultVideoDecoderFactory(remoteEglBase!!.eglBaseContext)

                peerConnectionFactory = PeerConnectionFactory.builder()
                    .setVideoEncoderFactory(encoderFactory)
                    .setVideoDecoderFactory(decoderFactory)
                    .createPeerConnectionFactory()

                createPeerConnection(
                    context,
                    peerConnectionFactory,
                    remoteView!!
                ) {
                    localPeer = it
                }

                initializeSocketIO()

                requestPermissionsIfNeeded()
            }
        }

        /**
         * 增强的折线图 Composable，带坐标轴和标签
         * 使用直线连接每个点
         */
        @Composable
        fun LineChart(
            data: List<Float>,
            modifier: Modifier = Modifier,
            lineColor: Color = Color.Green,
            backgroundColor: Color = Color.Black,
            yAxisLabel: String = "",
            xAxisLabel: String = "",
            minYValue: Float? = null,
            maxYValue: Float? = null
        ) {
            // 使用 Canvas 绘制折线图，或使用任何兼容 Compose 的图表库
        }

        private fun initializeSocketIO() {
            val protocol = if (signalingServerUrl.startsWith("https")) "https" else "http"
            val socketUrl = signalingServerUrl

            val options = IO.Options().apply {
                transports = arrayOf("websocket")
                secure = protocol == "https"
                path = "/socket.io/"
            }

            try {
                socket = IO.socket(socketUrl, options)

                socket.on(Socket.EVENT_CONNECT) {
                    Log.d(TAG, "Socket 已连接")
                    socket.emit("join", currentRoom)
                    Log.d(TAG, "加入房间: $currentRoom")
                    initiateCall()
                }

                socket.on(Socket.EVENT_CONNECT_ERROR) { args ->
                    if (args.isNotEmpty()) {
                        val error = args[0]
                        Log.e(TAG, "Socket 连接错误: $error")
                    }
                }

                socket.on(Socket.EVENT_DISCONNECT) { args ->
                    if (args.isNotEmpty()) {
                        val reason = args[0]
                        Log.d(TAG, "Socket 已断开: $reason")
                    }
                }

                socket.on("signal") { args ->
                    Log.d(TAG, "接收到信令: ${args[0]}")
                    if (args.isNotEmpty() && args[0] is JSONObject) {
                        val data = args[0] as JSONObject
                        handleSignalingData(data)
                    }
                }

                socket.connect()
                Log.d(TAG, "正在连接到 Socket: $socketUrl...")
            } catch (e: Exception) {
                Log.e(TAG, "连接 Socket 时出错: ${e.message}")
            }
        }

        private fun requestPermissionsIfNeeded() {
            // 请求必要的权限
            val permissions = arrayOf(
                Manifest.permission.CAMERA,
                Manifest.permission.RECORD_AUDIO
            )
            requestPermissionsLauncher.launch(permissions)
        }

        private fun onPermissionsChecked() {
            Toast.makeText(requireContext(), "所有必要的权限已被授予", Toast.LENGTH_SHORT).show()
            // 继续初始化视频或其他组件
        }

        private fun createPeerConnection(
            context: Context,
            peerConnectionFactory: PeerConnectionFactory,
            remoteView: SurfaceViewRenderer,
            onLocalPeerCreated: (PeerConnection) -> Unit
        ) {
            // 创建 PeerConnection 的实现
        }

        private fun initiateCall() {
            // 发起呼叫的实现，例如创建 offer
        }

        private fun handleSignalingData(data: JSONObject) {
            Log.d(TAG, "处理信令数据: $data")
            when (data.getString("type")) {

                "answer" -> {
                    Log.d(TAG, "接收到 answer")
                    val sdp = SessionDescription(
                        SessionDescription.Type.ANSWER,
                        data.getJSONObject("sdp").getString("sdp")
                    )

                    localPeer?.setRemoteDescription(object : SdpObserver {
                        override fun onSetSuccess() {
                            pendingIceCandidates.forEach { candidate ->
                                localPeer?.addIceCandidate(candidate)
                            }

                            pendingIceCandidates.clear()

                            Log.d(TAG, "设置远程描述（answer）成功")
                        }

                        override fun onSetFailure(error: String?) {
                            Log.e(TAG, "设置远程描述（answer）错误: $error")
                        }

                        override fun onCreateSuccess(p0: SessionDescription?) {}
                        override fun onCreateFailure(p0: String?) {}
                    }, sdp)
                }

                "ice" -> {
                    Log.d(TAG, "接收到 ICE candidate")
                    val candidateData = data.getJSONObject("candidate")
                    val candidate = IceCandidate(
                        candidateData.getString("sdpMid"),
                        candidateData.getInt("sdpMLineIndex"),
                        candidateData.getString("candidate")
                    )

                    if (localPeer?.remoteDescription != null) {
                        localPeer?.addIceCandidate(candidate)
                    } else {
                        pendingIceCandidates.add(candidate)
                    }
                }

                "time_sync_request" -> {
                    val t1 = data.getLong("t1")
                    val t2 = System.currentTimeMillis()
                    val t3 = t2 // 假设处理时间为零，如果有处理延迟，可以记录实际处理完成时间
                    val syncResponse = JSONObject().apply {
                        put("type", "time_sync_response")
                        put("t1", t1)
                        put("t2", t2)
                        put("t3", t3)
                        put("room", currentRoom)
                    }
                    socket.emit("signal", syncResponse)
                    Log.d(TAG, "回复 time_sync_request: t1=$t1, t2=$t2, t3=$t3")

                    // 计算 OWD，考虑时钟偏移量
                    val adjustedT2 = t2 - clockOffset
                    val owd = adjustedT2 - t1
                    if (owd >= 0) {
                        Log.d(TAG, "时间同步: OWD=$owd ms")
                    } else {
                        Log.e(TAG, "计算的 OWD 为负数: OWD=$owd ms，可能由于时钟偏移未同步或计算错误。")
                    }

                    viewLifecycleOwner.lifecycleScope.launch {
                        // 更新 OWD 状态
                        owdState.longValue = owd

                        // 更新 OWD 历史记录
                        owdHistory.add(owd)
                        if (owdHistory.size > 60) {
                            owdHistory.removeAt(0)
                        }

                        // 计算 OWD 的最大、最小和平均值
                        val maxOwd = owdHistory.maxOrNull() ?: 0L
                        val minOwd = owdHistory.minOrNull() ?: 0L
                        val averageOwd = if (owdHistory.isNotEmpty()) owdHistory.average().toLong() else 0L

                        Log.d(TAG, "OWD - 最新: $owd ms, 最大: $maxOwd ms, 最小: $minOwd ms, 平均: $averageOwd ms")
                    }
                }

                "clock_offset" -> {
                    clockOffset = data.getLong("offset")
                    Log.d(TAG, "接收到时钟偏移量: offset=$clockOffset ms")
                }

                else -> {
                    Log.e(TAG, "未知的信令类型: ${data.getString("type")}")
                }
            }
        }

        private fun startStatsCollection() {
            Log.d(TAG, "开始收集统计数据...")
            statsJob = viewLifecycleOwner.lifecycleScope.launch {
                while (isActive) {
                    delay(1000) // 每秒收集一次统计数据
                    Log.d(TAG, "收集统计数据...")
                    localPeer?.getStats { report ->
                        Log.d(TAG, "已获取统计报告。")
                        parseStatsReport(report)
                    } ?: Log.e(TAG, "获取统计数据失败: localPeer 为 null.")
                }
            }
        }

        private fun parseStatsReport(report: RTCStatsReport) {
            Log.d(TAG, "接收到 RTCStatsReport: $report")
            for (stats in report.statsMap.values) {
                if (stats.type == "inbound-rtp") {
                    val kind = stats.members["kind"] as? String
                    if (kind == "video") {
                        val framesDecoded = (stats.members["framesDecoded"] as? Number)?.toDouble() ?: 0.0
                        val framesReceived = (stats.members["framesReceived"] as? Number)?.toDouble() ?: 0.0
                        val framesDropped = (stats.members["framesDropped"] as? Number)?.toDouble() ?: 0.0
                        val bytesReceived = (stats.members["bytesReceived"] as? Number)?.toDouble() ?: 0.0
                        val packetsLost = (stats.members["packetsLost"] as? Number)?.toDouble() ?: 0.0
                        val packetsReceived = (stats.members["packetsReceived"] as? Number)?.toDouble() ?: 1.0 // 避免除零
                        val packetLossFraction = packetsLost / (packetsLost + packetsReceived)
                        val timestamp = stats.timestampUs / 1_000_000.0 // 转换为秒

                        Log.d(
                            TAG,
                            "统计数据 - 解码帧数: $framesDecoded, 接收帧数: $framesReceived, 丢弃帧数: $framesDropped, 接收字节数: $bytesReceived, 丢包率: $packetLossFraction, 时间戳: $timestamp"
                        )

                        if (prevTimestamp != 0.0) {
                            val timeElapsed = timestamp - prevTimestamp
                            val framesDelta = framesDecoded - prevFramesDecoded
                            val bytesDelta = bytesReceived - prevBytesReceived
                            val framesReceivedDelta = framesReceived - prevFramesReceived
                            val framesDroppedDelta = framesDropped - prevFramesDropped

                            val frameRate = if (timeElapsed > 0) framesDelta / timeElapsed else 0.0
                            val bitrate = if (timeElapsed > 0) (bytesDelta * 8) / timeElapsed else 0.0 // 比特每秒
                            val packetLoss = packetLossFraction * 100 // 转换为百分比

                            Log.d(TAG, "计算的帧率: $frameRate fps, 码率: $bitrate bps, 丢包率: $packetLoss%")

                            // 根据阈值判断是否卡顿
                            val isStuttering = frameRate < 24 || packetLoss > 5.0 // 阈值可调整

                            // 更新状态
                            viewLifecycleOwner.lifecycleScope.launch {
                                frameRateState.doubleValue = frameRate
                                bitrateState.longValue = bitrate.toLong()
                                // 更新卡顿状态
                                stutteringState.value = isStuttering
                                // 更新具体卡顿原因
                                frameRateLowState.value = frameRate < 24
                                packetLossHighState.value = packetLoss > 5.0
                                packetLossState.doubleValue = packetLoss

                                // 更新历史记录
                                frameRateHistory.add(frameRate.toFloat())
                                if (frameRateHistory.size > 60) {
                                    frameRateHistory.removeAt(0)
                                }

                                bitrateHistory.add(bitrate.toLong())
                                if (bitrateHistory.size > 60) {
                                    bitrateHistory.removeAt(0)
                                }

                                Log.d(
                                    TAG,
                                    "更新的帧率: ${frameRateState.doubleValue} fps, 码率: ${bitrateState.longValue / 1000} kbps, 卡顿: $isStuttering"
                                )
                            }
                        }

                        // 更新之前的值
                        prevFramesDecoded = framesDecoded
                        prevBytesReceived = bytesReceived
                        prevFramesReceived = framesReceived
                        prevFramesDropped = framesDropped
                        prevTimestamp = timestamp
                    }
                }
            }
        }

        override fun onDestroyView() {
            super.onDestroyView()
            statsJob?.cancel()
            socket.disconnect()
            localPeer?.dispose()
            remoteView?.release()
            remoteEglBase?.release()
            timeSyncJob?.cancel()
        }
    }

关键点说明

时钟偏移量的计算与传递：
- 发起端在接收到 time_sync_response 后，计算 RTT 和时钟偏移量。
- 通过信令通道将时钟偏移量发送给接收端。
接收端调整 OWD 计算：
- 接收端在接收到时钟偏移量后，使用 owd = (t2 - offset) - t1 来计算 OWD。
- 这样可以消除由于时钟不同步带来的负数问题。
确保时钟偏移量在 OWD 计算前已知：
- 接收端需要在处理 time_sync_request 前确保已经接收到并存储了时钟偏移量。如果未接收到偏移量，可以选择不计算 OWD 或等待偏移量的更新。

进一步优化建议

多次时间同步：为了提高时钟偏移量的准确性，可以进行多次时间同步请求，并取平均值或使用其他滤波方法来减少误差。
异常处理：增强异常处理机制，确保在时钟偏移量计算失败或数据异常时，应用能够正确处理，避免 OWD 出现负数。
时钟同步协议：如果需要更高精度的时钟同步，可以考虑集成成熟的时钟同步协议（如 NTP 或 PTP），但这通常需要服务器端的支持。

通过上述修改和优化，应该能够有效解决单向时延（OWD）出现负数的问题，确保 OWD 的计算准确可靠。

سؤال

الفكرة

الإجابة

Key Changes:

Modified VideoInitiatorFragment:

Modified VideoReceiverFragment:

Explanation of Changes:

Additional Recommendations:

سؤال

الفكرة

الإجابة

主要修改点：

修改后的 VideoInitiatorFragment：

修改后的 VideoReceiverFragment：

说明：

其他建议：

سؤال

الفكرة

الإجابة

原因分析

解决方案

实现步骤

1. 修改时间同步协议

2. 发送时钟偏移量给接收端

3. 调整 OWD 的计算

完整的代码修正

关键点说明

进一步优化建议

مشاركة هذا السؤال والجواب

Modified `VideoInitiatorFragment`:

Modified `VideoReceiverFragment`:

修改后的 `VideoInitiatorFragment`：

修改后的 `VideoReceiverFragment`：