refactor(app): 重构应用架构并优化设置管理

- 将 MainActivity 中的 UI 组件提取到独立的 PosefitApp Composable 函数中
- 创建 StreamSettings 和 StreamSettingsStore 类以统一管理流媒体设置
- 移除 MainActivity 中大量的内联 Composable 函数和状态管理代码
- 更新 PosefitStreamingService 以使用新的设置存储机制
- 简化服务启动逻辑并将 StreamSettings 对象作为参数传递
- 迁移所有设置相关的 SharedPreferences 操作到专门的设置存储类中

app/src/main/AndroidManifest.xml

@@ -4,6 +4,9 @@
 
     <!-- 摄像头权限 -->
     <uses-permission android:name="android.permission.CAMERA" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE" />
+    <uses-permission android:name="android.permission.FOREGROUND_SERVICE_CAMERA" />
+    <uses-permission android:name="android.permission.POST_NOTIFICATIONS" />
 
     <!-- 网络权限：WebRTC / WebSocket / 信令服务器需要 -->
     <uses-permission android:name="android.permission.INTERNET" />
@@ -28,7 +31,8 @@
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/Theme.Posefit">
+        android:theme="@style/Theme.Posefit"
+        android:usesCleartextTraffic="true">
 
         <activity
             android:name=".MainActivity"
@@ -39,6 +43,11 @@
             </intent-filter>
         </activity>
 
+        <service
+            android:name=".PosefitStreamingService"
+            android:exported="false"
+            android:foregroundServiceType="camera" />
+
     </application>
 
 </manifest>

app/src/main/kotlin/com/kimgo/posefit/MainActivity.kt

@@ -1,123 +1,111 @@
 package com.kimgo.posefit
 
 import android.Manifest
-import android.content.Context
+import android.os.Build
 import android.os.Bundle
+import android.view.WindowManager
 import androidx.activity.ComponentActivity
 import androidx.activity.compose.setContent
 import androidx.activity.result.contract.ActivityResultContracts
-import androidx.compose.foundation.layout.*
+import androidx.compose.foundation.layout.fillMaxSize
-import androidx.compose.material3.*
+import androidx.compose.material3.MaterialTheme
-import androidx.compose.runtime.*
+import androidx.compose.material3.Surface
-import androidx.compose.ui.Alignment
 import androidx.compose.ui.Modifier
-import androidx.compose.ui.unit.dp
+import com.kimgo.posefit.sender.StreamOrientation
-import com.kimgo.posefit.sender.WebRtcSenderClient
+import com.kimgo.posefit.settings.StreamSettings
+import com.kimgo.posefit.settings.StreamSettingsStore
+import com.kimgo.posefit.ui.PosefitApp
 import timber.log.Timber
 
 class MainActivity : ComponentActivity() {
 
-    private var webRtcClient: WebRtcSenderClient? = null
+    private lateinit var settingsStore: StreamSettingsStore
+    private var permissionResultHandler: ((Boolean) -> Unit)? = null
 
     private val requestPermission =
-        registerForActivityResult(ActivityResultContracts.RequestPermission()) { granted ->
+        registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { grants ->
-            if (granted) {
+            val cameraGranted = grants[Manifest.permission.CAMERA] == true
-                val url = getSavedSignalingUrl()
+            if (cameraGranted) {
-                startWebRtc(url)
+                startWebRtc(settingsStore.get())
             } else {
                 Timber.w("Camera permission denied")
             }
+            permissionResultHandler?.invoke(cameraGranted)
+            permissionResultHandler = null
         }
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         Timber.d("MainActivity onCreate")
 
+        settingsStore = StreamSettingsStore(this)
+        applyStreamOrientation(settingsStore.get().orientation)
+        window.addFlags(WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
+
         setContent {
             MaterialTheme {
                 Surface(
                     modifier = Modifier.fillMaxSize(),
-                    color = MaterialTheme.colorScheme.background
+                    color = MaterialTheme.colorScheme.background,
                 ) {
-                    ConfigScreen()
+                    PosefitApp(
+                        context = this,
+                        initialSettings = settingsStore.get(),
+                        isInitiallyStreaming = PosefitStreamingService.isRunning,
+                        onStartStreaming = { _, onPermissionResult ->
+                            permissionResultHandler = onPermissionResult
+                            requestPermission.launch(requiredPermissions())
+                        },
+                        onStopStreaming = ::stopWebRtc,
+                        onSaveSettings = settingsStore::save,
+                        onApplyOrientation = { applyStreamOrientation(it.orientation) },
+                    )
                 }
             }
         }
     }
 
-    @Composable
+    private fun applyStreamOrientation(orientation: StreamOrientation) {
-    fun ConfigScreen() {
+        requestedOrientation = orientation.activityOrientation
-        var url by remember { mutableStateOf(getSavedSignalingUrl()) }
-        var isStreaming by remember { mutableStateOf(false) }
-
-        Column(
-            modifier = Modifier
-                .fillMaxSize()
-                .padding(24.dp),
-            verticalArrangement = Arrangement.Center,
-            horizontalAlignment = Alignment.CenterHorizontally
-        ) {
-            Text(
-                text = "PoseFit 配置",
-                style = MaterialTheme.typography.headlineMedium,
-                color = MaterialTheme.colorScheme.primary
-            )
-            Spacer(modifier = Modifier.height(32.dp))
-            TextField(
-                value = url,
-                onValueChange = { url = it },
-                label = { Text("服务器地址 (ws://...)") },
-                modifier = Modifier.fillMaxWidth(),
-                enabled = !isStreaming
-            )
-            Spacer(modifier = Modifier.height(16.dp))
-            Button(
-                onClick = {
-                    if (isStreaming) {
-                        stopWebRtc()
-                        isStreaming = false
-                    } else {
-                        saveSignalingUrl(url)
-                        requestPermission.launch(Manifest.permission.CAMERA)
-                        isStreaming = true
-                    }
-                },
-                modifier = Modifier.fillMaxWidth()
-            ) {
-                Text(if (isStreaming) "停止推流" else "开始推流")
-            }
-        }
     }
 
-    private fun getSavedSignalingUrl(): String {
+    private fun startWebRtc(settings: StreamSettings) {
-        val prefs = getSharedPreferences("posefit_prefs", Context.MODE_PRIVATE)
+        Timber.i(
-        return prefs.getString("signaling_url", "ws://192.168.2.10:8765") ?: "ws://192.168.2.10:8765"
+            "startWebRtc: %s, cameraFacing=%s, cameraName=%s, resolution=%s, orientation=%s",
-    }
+            settings.signalingUrl,
-
+            settings.cameraFacing,
-    private fun saveSignalingUrl(url: String) {
+            settings.cameraName,
-        val prefs = getSharedPreferences("posefit_prefs", Context.MODE_PRIVATE)
+            settings.resolution.label,
-        prefs.edit().putString("signaling_url", url).apply()
+            settings.orientation,
-    }
-
-    private fun startWebRtc(url: String) {
-        Timber.i("startWebRtc: %s", url)
-        webRtcClient?.release()
-        webRtcClient = WebRtcSenderClient(
-            context = this,
-            signalingUrl = url
         )
-        webRtcClient?.start()
+        applyStreamOrientation(settings.orientation)
+        val intent = PosefitStreamingService.startIntent(
+            context = this,
+            settings = settings,
+        )
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            startForegroundService(intent)
+        } else {
+            startService(intent)
+        }
     }
 
     private fun stopWebRtc() {
         Timber.i("stopWebRtc")
-        webRtcClient?.release()
+        startService(PosefitStreamingService.stopIntent(this))
-        webRtcClient = null
+    }
+
+    private fun requiredPermissions(): Array<String> {
+        return buildList {
+            add(Manifest.permission.CAMERA)
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.TIRAMISU) {
+                add(Manifest.permission.POST_NOTIFICATIONS)
+            }
+        }.toTypedArray()
     }
 
     override fun onDestroy() {
         super.onDestroy()
-        stopWebRtc()
         Timber.d("MainActivity onDestroy")
     }
 }

app/src/main/kotlin/com/kimgo/posefit/PosefitStreamingService.kt

@@ -0,0 +1,190 @@
+package com.kimgo.posefit
+
+import android.app.Notification
+import android.app.NotificationChannel
+import android.app.NotificationManager
+import android.app.Service
+import android.content.Context
+import android.content.Intent
+import android.content.pm.ServiceInfo
+import android.os.Build
+import android.os.IBinder
+import com.kimgo.posefit.sender.CameraFacing
+import com.kimgo.posefit.sender.StreamOrientation
+import com.kimgo.posefit.sender.StreamResolution
+import com.kimgo.posefit.sender.WebRtcSenderClient
+import com.kimgo.posefit.settings.StreamSettings
+import com.kimgo.posefit.settings.StreamSettingsStore
+import timber.log.Timber
+
+class PosefitStreamingService : Service() {
+
+    private var webRtcClient: WebRtcSenderClient? = null
+
+    override fun onCreate() {
+        super.onCreate()
+        createNotificationChannel()
+    }
+
+    override fun onStartCommand(intent: Intent?, flags: Int, startId: Int): Int {
+        when (intent?.action) {
+            ACTION_STOP -> {
+                stopStreaming()
+                stopSelf()
+                return START_NOT_STICKY
+            }
+
+            ACTION_START -> {
+                val settings = StreamSettings(
+                    signalingUrl = intent.getStringExtra(EXTRA_SIGNALING_URL)
+                        ?: StreamSettingsStore.DEFAULT_SIGNALING_URL,
+                    cameraFacing = intent.getStringExtra(EXTRA_CAMERA_FACING)
+                        ?.let { runCatching { CameraFacing.valueOf(it) }.getOrNull() }
+                        ?: CameraFacing.BACK,
+                    cameraName = intent.getStringExtra(EXTRA_CAMERA_NAME),
+                    resolution = StreamResolution.from(
+                        intent.getIntExtra(EXTRA_VIDEO_WIDTH, StreamResolution.DEFAULT.width),
+                        intent.getIntExtra(EXTRA_VIDEO_HEIGHT, StreamResolution.DEFAULT.height),
+                    ),
+                    orientation = intent.getStringExtra(EXTRA_STREAM_ORIENTATION)
+                        ?.let { runCatching { StreamOrientation.valueOf(it) }.getOrNull() }
+                        ?: StreamOrientation.DEFAULT,
+                )
+                startForegroundNotification(settings)
+                startStreaming(settings)
+                return START_STICKY
+            }
+
+            else -> {
+                val settings = StreamSettingsStore(this).get()
+                startForegroundNotification(settings)
+                startStreaming(settings)
+                return START_STICKY
+            }
+        }
+    }
+
+    override fun onBind(intent: Intent?): IBinder? = null
+
+    override fun onDestroy() {
+        stopStreaming()
+        super.onDestroy()
+    }
+
+    private fun startStreaming(settings: StreamSettings) {
+        Timber.i(
+            "Streaming service start: %s, cameraFacing=%s, preferredCameraName=%s, resolution=%s, orientation=%s",
+            settings.signalingUrl,
+            settings.cameraFacing,
+            settings.cameraName,
+            settings.resolution.label,
+            settings.orientation,
+        )
+        webRtcClient?.release()
+        webRtcClient = WebRtcSenderClient(
+            context = applicationContext,
+            signalingUrl = settings.signalingUrl,
+            cameraFacing = settings.cameraFacing,
+            preferredCameraName = settings.cameraName,
+            videoWidth = settings.resolution.width,
+            videoHeight = settings.resolution.height,
+            streamOrientation = settings.orientation,
+        ).also { it.start() }
+        isRunning = true
+    }
+
+    private fun stopStreaming() {
+        Timber.i("Streaming service stop")
+        webRtcClient?.release()
+        webRtcClient = null
+        isRunning = false
+    }
+
+    private fun startForegroundNotification(settings: StreamSettings) {
+        val notification = buildNotification(settings)
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.Q) {
+            startForeground(NOTIFICATION_ID, notification, ServiceInfo.FOREGROUND_SERVICE_TYPE_CAMERA)
+        } else {
+            startForeground(NOTIFICATION_ID, notification)
+        }
+    }
+
+    private fun buildNotification(settings: StreamSettings): Notification {
+        val cameraText = when (settings.cameraFacing) {
+            CameraFacing.FRONT -> "前置摄像头"
+            CameraFacing.BACK -> "后置摄像头"
+        }
+        val cameraModeText = settings.cameraName
+            ?.let { "$cameraText $it" }
+            ?: "$cameraText 自动最广角"
+        val streamText = "${settings.resolution.label} ${settings.orientation.label}"
+
+        return if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+            Notification.Builder(this, CHANNEL_ID)
+                .setContentTitle("PoseFit 正在推流")
+                .setContentText("$cameraModeText $streamText -> ${settings.signalingUrl}")
+                .setSmallIcon(R.mipmap.ic_launcher)
+                .setOngoing(true)
+                .build()
+        } else {
+            Notification.Builder(this)
+                .setContentTitle("PoseFit 正在推流")
+                .setContentText("$cameraModeText $streamText -> ${settings.signalingUrl}")
+                .setSmallIcon(R.mipmap.ic_launcher)
+                .setOngoing(true)
+                .build()
+        }
+    }
+
+    private fun createNotificationChannel() {
+        if (Build.VERSION.SDK_INT < Build.VERSION_CODES.O) {
+            return
+        }
+
+        val channel = NotificationChannel(
+            CHANNEL_ID,
+            "PoseFit 推流",
+            NotificationManager.IMPORTANCE_LOW,
+        )
+        val manager = getSystemService(NotificationManager::class.java)
+        manager.createNotificationChannel(channel)
+    }
+
+    companion object {
+        private const val CHANNEL_ID = "posefit_streaming"
+        private const val NOTIFICATION_ID = 1001
+        private const val ACTION_START = "com.kimgo.posefit.action.START_STREAMING"
+        private const val ACTION_STOP = "com.kimgo.posefit.action.STOP_STREAMING"
+        private const val EXTRA_SIGNALING_URL = "extra_signaling_url"
+        private const val EXTRA_CAMERA_FACING = "extra_camera_facing"
+        private const val EXTRA_CAMERA_NAME = "extra_camera_name"
+        private const val EXTRA_VIDEO_WIDTH = "extra_video_width"
+        private const val EXTRA_VIDEO_HEIGHT = "extra_video_height"
+        private const val EXTRA_STREAM_ORIENTATION = "extra_stream_orientation"
+
+        @Volatile
+        var isRunning: Boolean = false
+            private set
+
+        fun startIntent(
+            context: Context,
+            settings: StreamSettings,
+        ): Intent {
+            return Intent(context, PosefitStreamingService::class.java).apply {
+                action = ACTION_START
+                putExtra(EXTRA_SIGNALING_URL, settings.signalingUrl)
+                putExtra(EXTRA_CAMERA_FACING, settings.cameraFacing.name)
+                putExtra(EXTRA_CAMERA_NAME, settings.cameraName)
+                putExtra(EXTRA_VIDEO_WIDTH, settings.resolution.width)
+                putExtra(EXTRA_VIDEO_HEIGHT, settings.resolution.height)
+                putExtra(EXTRA_STREAM_ORIENTATION, settings.orientation.name)
+            }
+        }
+
+        fun stopIntent(context: Context): Intent {
+            return Intent(context, PosefitStreamingService::class.java).apply {
+                action = ACTION_STOP
+            }
+        }
+    }
+}

app/src/main/kotlin/com/kimgo/posefit/sender/CameraCatalog.kt

@@ -0,0 +1,50 @@
+package com.kimgo.posefit.sender
+
+import android.content.Context
+import android.hardware.camera2.CameraCharacteristics
+import android.hardware.camera2.CameraManager
+import org.webrtc.Camera2Enumerator
+
+object CameraCatalog {
+    fun listOptions(context: Context): List<CameraOption> {
+        val enumerator = Camera2Enumerator(context)
+        val cameraManager = context.getSystemService(Context.CAMERA_SERVICE) as CameraManager
+
+        return enumerator.deviceNames.mapNotNull { cameraName ->
+            val facing = when {
+                enumerator.isFrontFacing(cameraName) -> CameraFacing.FRONT
+                enumerator.isBackFacing(cameraName) -> CameraFacing.BACK
+                else -> return@mapNotNull null
+            }
+            val focalLengths = runCatching {
+                cameraManager.getCameraCharacteristics(cameraName)
+                    .get(CameraCharacteristics.LENS_INFO_AVAILABLE_FOCAL_LENGTHS)
+                    ?.toList()
+                    .orEmpty()
+            }.getOrDefault(emptyList())
+            val supportedResolutions = enumerator.getSupportedFormats(cameraName)
+                ?.map { StreamResolution(it.width, it.height) }
+                ?.distinct()
+                ?.sortedWith(compareBy<StreamResolution> { it.width * it.height }.thenBy { it.width })
+                .orEmpty()
+
+            CameraOption(
+                name = cameraName,
+                facing = facing,
+                focalLengths = focalLengths,
+                supportedResolutions = supportedResolutions,
+            )
+        }.sortedWith(
+            compareBy<CameraOption> { it.facing != CameraFacing.BACK }
+                .thenBy { it.minFocalLength ?: Float.MAX_VALUE }
+                .thenBy { it.name }
+        )
+    }
+
+    fun widestBackCameraName(context: Context): String? {
+        return listOptions(context)
+            .filter { it.facing == CameraFacing.BACK }
+            .minByOrNull { it.minFocalLength ?: Float.MAX_VALUE }
+            ?.name
+    }
+}

app/src/main/kotlin/com/kimgo/posefit/sender/CameraFacing.kt

@@ -0,0 +1,6 @@
+package com.kimgo.posefit.sender
+
+enum class CameraFacing {
+    FRONT,
+    BACK
+}

app/src/main/kotlin/com/kimgo/posefit/sender/CameraOption.kt

@@ -0,0 +1,21 @@
+package com.kimgo.posefit.sender
+
+data class CameraOption(
+    val name: String,
+    val facing: CameraFacing,
+    val focalLengths: List<Float>,
+    val supportedResolutions: List<StreamResolution>,
+) {
+    val minFocalLength: Float?
+        get() = focalLengths.minOrNull()
+
+    val label: String
+        get() {
+            val facingText = when (facing) {
+                CameraFacing.FRONT -> "前置"
+                CameraFacing.BACK -> "后置"
+            }
+            val focalText = minFocalLength?.let { "%.2fmm".format(it) } ?: "未知焦距"
+            return "$facingText $focalText ($name)"
+        }
+}

app/src/main/kotlin/com/kimgo/posefit/sender/StreamOrientation.kt

@@ -0,0 +1,24 @@
+package com.kimgo.posefit.sender
+
+import android.content.pm.ActivityInfo
+
+enum class StreamOrientation(
+    val label: String,
+    val activityOrientation: Int,
+) {
+    LANDSCAPE("横屏", ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE),
+    REVERSE_LANDSCAPE("反向横屏", ActivityInfo.SCREEN_ORIENTATION_REVERSE_LANDSCAPE),
+    PORTRAIT("竖屏", ActivityInfo.SCREEN_ORIENTATION_PORTRAIT);
+
+    fun next(): StreamOrientation {
+        return when (this) {
+            LANDSCAPE -> REVERSE_LANDSCAPE
+            REVERSE_LANDSCAPE -> PORTRAIT
+            PORTRAIT -> LANDSCAPE
+        }
+    }
+
+    companion object {
+        val DEFAULT = LANDSCAPE
+    }
+}

app/src/main/kotlin/com/kimgo/posefit/sender/StreamResolution.kt

@@ -0,0 +1,26 @@
+package com.kimgo.posefit.sender
+
+data class StreamResolution(
+    val width: Int,
+    val height: Int,
+) {
+    val label: String
+        get() = "${width}x$height"
+
+    companion object {
+        val DEFAULT = StreamResolution(1280, 720)
+
+        val PRESETS = listOf(
+            StreamResolution(640, 480),
+            StreamResolution(960, 720),
+            StreamResolution(1280, 720),
+            StreamResolution(1280, 960),
+            StreamResolution(1920, 1080),
+        )
+
+        fun from(width: Int, height: Int): StreamResolution {
+            return PRESETS.firstOrNull { it.width == width && it.height == height }
+                ?: StreamResolution(width, height)
+        }
+    }
+}

app/src/main/kotlin/com/kimgo/posefit/sender/WebRtcSenderClient.kt

@@ -8,9 +8,20 @@ import timber.log.Timber
 
 class WebRtcSenderClient(
     private val context: Context,
-    private val signalingUrl: String
+    private val signalingUrl: String,
+    private val cameraFacing: CameraFacing = CameraFacing.BACK,
+    private val preferredCameraName: String? = null,
+    private val videoWidth: Int = StreamResolution.DEFAULT.width,
+    private val videoHeight: Int = StreamResolution.DEFAULT.height,
+    private val streamOrientation: StreamOrientation = StreamOrientation.DEFAULT,
 ) {
 
+    private companion object {
+        const val VIDEO_FPS = 30
+        const val VIDEO_MIN_BITRATE_BPS = 3_000_000
+        const val VIDEO_MAX_BITRATE_BPS = 6_000_000
+    }
+
     private val eglBase = EglBase.create()
     private val okHttpClient = OkHttpClient()
 
@@ -21,10 +32,21 @@ class WebRtcSenderClient(
     private var videoCapturer: CameraVideoCapturer? = null
     private var videoSource: VideoSource? = null
     private var videoTrack: VideoTrack? = null
+    private var videoSender: RtpSender? = null
     private var surfaceTextureHelper: SurfaceTextureHelper? = null
+    private var capturedFrameCount = 0L
+    private var lastFrameSignature: String? = null
 
     fun start() {
-        Timber.i("WebRTC starting, signalingUrl=%s", signalingUrl)
+        Timber.i(
+            "WebRTC starting, signalingUrl=%s, cameraFacing=%s, preferredCameraName=%s, resolution=%dx%d, orientation=%s",
+            signalingUrl,
+            cameraFacing,
+            preferredCameraName,
+            videoWidth,
+            videoHeight,
+            streamOrientation,
+        )
         initPeerConnectionFactory()
         connectSignaling()
     }
@@ -129,9 +151,7 @@ class WebRtcSenderClient(
     private fun startCamera() {
         val enumerator = Camera2Enumerator(context)
 
-        val cameraName = enumerator.deviceNames.firstOrNull {
+        val cameraName = selectCamera(enumerator)
-            enumerator.isFrontFacing(it)
-        } ?: enumerator.deviceNames.first()
 
         videoCapturer = enumerator.createCapturer(cameraName, null)
 
@@ -141,23 +161,167 @@ class WebRtcSenderClient(
         )
 
         videoSource = factory.createVideoSource(false)
+        capturedFrameCount = 0L
+        lastFrameSignature = null
+        val capturerObserver = videoSource?.capturerObserver
+            ?.let { createLoggingCapturerObserver(it) }
 
         videoCapturer?.initialize(
             surfaceTextureHelper,
             context,
-            videoSource?.capturerObserver
+            capturerObserver
         )
 
-        videoCapturer?.startCapture(1280, 720, 30)
+        Timber.i(
+            "Starting camera capture: camera=%s, requested=%dx%d@%dfps",
+            cameraName,
+            videoWidth,
+            videoHeight,
+            VIDEO_FPS,
+        )
+        videoCapturer?.startCapture(videoWidth, videoHeight, VIDEO_FPS)
 
         videoTrack = factory.createVideoTrack("video_track", videoSource)
 
-        peerConnection?.addTrack(
+        videoSender = peerConnection?.addTrack(
             videoTrack,
             listOf("posefit_stream")
         )
+        videoSender?.let { configureVideoSender(it) }
 
-        Timber.d("Camera started: %s, resolution=1280x720@30fps", cameraName)
+        Timber.d("Camera started: %s, resolution=%dx%d@%dfps", cameraName, videoWidth, videoHeight, VIDEO_FPS)
+    }
+
+    private fun configureVideoSender(sender: RtpSender) {
+        val parameters = sender.parameters ?: run {
+            Timber.w("Video sender parameters unavailable")
+            return
+        }
+
+        parameters.degradationPreference = RtpParameters.DegradationPreference.MAINTAIN_RESOLUTION
+        parameters.encodings.forEach { encoding ->
+            encoding.active = true
+            encoding.scaleResolutionDownBy = 1.0
+            encoding.maxFramerate = VIDEO_FPS
+            encoding.minBitrateBps = VIDEO_MIN_BITRATE_BPS
+            encoding.maxBitrateBps = VIDEO_MAX_BITRATE_BPS
+        }
+
+        val applied = sender.setParameters(parameters)
+        Timber.d(
+            "Video sender configured: applied=%s, resolution=%dx%d@%dfps, bitrate=%d-%d",
+            applied,
+            videoWidth,
+            videoHeight,
+            VIDEO_FPS,
+            VIDEO_MIN_BITRATE_BPS,
+            VIDEO_MAX_BITRATE_BPS,
+        )
+    }
+
+    private fun selectCamera(enumerator: Camera2Enumerator): String {
+        logAvailableCameras(enumerator)
+
+        if (!preferredCameraName.isNullOrBlank() && preferredCameraName in enumerator.deviceNames) {
+            Timber.i("Selected explicit camera: %s", preferredCameraName)
+            return preferredCameraName
+        }
+
+        val preferredCamera = when (cameraFacing) {
+            CameraFacing.FRONT -> enumerator.deviceNames.firstOrNull { enumerator.isFrontFacing(it) }
+            CameraFacing.BACK -> selectWidestBackCamera(enumerator)
+        }
+
+        if (preferredCamera != null) {
+            return preferredCamera
+        }
+
+        Timber.w("Preferred camera not found: %s, falling back to first available camera", cameraFacing)
+        return enumerator.deviceNames.first()
+    }
+
+    private fun selectWidestBackCamera(enumerator: Camera2Enumerator): String? {
+        val backCameras = enumerator.deviceNames.filter { enumerator.isBackFacing(it) }
+        if (backCameras.isEmpty()) {
+            return null
+        }
+
+        val widestCamera = CameraCatalog.widestBackCameraName(context)
+
+        Timber.i("Selected widest back camera: %s", widestCamera)
+        return widestCamera ?: backCameras.first()
+    }
+
+    private fun logAvailableCameras(enumerator: Camera2Enumerator) {
+        val knownOptions = CameraCatalog.listOptions(context).associateBy { it.name }
+        Timber.i("Available WebRTC cameras: count=%d", enumerator.deviceNames.size)
+        enumerator.deviceNames.forEach { cameraName ->
+            val option = knownOptions[cameraName]
+            val formats = enumerator.getSupportedFormats(cameraName) ?: emptyList()
+            Timber.i(
+                "Camera available: name=%s, facing=%s, focalLengths=%s, supportedFormats=%d",
+                cameraName,
+                option?.facing ?: "unknown",
+                option?.focalLengths,
+                formats.size,
+            )
+
+            formats
+                .sortedWith(
+                    compareBy<CameraEnumerationAndroid.CaptureFormat> { it.width * it.height }
+                        .thenBy { it.framerate.max }
+                )
+                .forEach { format ->
+                    Timber.i(
+                        "Camera format: name=%s, size=%dx%d, fps=%.1f-%.1f",
+                        cameraName,
+                        format.width,
+                        format.height,
+                        format.framerate.min / 1000.0,
+                        format.framerate.max / 1000.0,
+                    )
+                }
+        }
+    }
+
+    private fun createLoggingCapturerObserver(delegate: CapturerObserver): CapturerObserver {
+        return object : CapturerObserver {
+            override fun onCapturerStarted(success: Boolean) {
+                Timber.i("Camera capturer started: success=%s", success)
+                delegate.onCapturerStarted(success)
+            }
+
+            override fun onCapturerStopped() {
+                Timber.i("Camera capturer stopped")
+                delegate.onCapturerStopped()
+            }
+
+            override fun onFrameCaptured(frame: VideoFrame) {
+                capturedFrameCount += 1
+
+                val buffer = frame.buffer
+                val signature = "${buffer.width}x${buffer.height}, rotation=${frame.rotation}"
+                if (
+                    signature != lastFrameSignature ||
+                    capturedFrameCount == 1L ||
+                    capturedFrameCount % 100L == 0L
+                ) {
+                    Timber.i(
+                        "Camera frame captured: frame=%d, buffer=%dx%d, rotated=%dx%d, rotation=%d, timestampNs=%d",
+                        capturedFrameCount,
+                        buffer.width,
+                        buffer.height,
+                        frame.rotatedWidth,
+                        frame.rotatedHeight,
+                        frame.rotation,
+                        frame.timestampNs,
+                    )
+                    lastFrameSignature = signature
+                }
+
+                delegate.onFrameCaptured(frame)
+            }
+        }
     }
 
     private fun createOffer() {
@@ -173,11 +337,16 @@ class WebRtcSenderClient(
         peerConnection?.createOffer(object : SdpObserver {
 
             override fun onCreateSuccess(desc: SessionDescription) {
+                val fixedVideoDesc = SessionDescription(
+                    desc.type,
+                    forceVideoBandwidth(desc.description)
+                )
+
                 peerConnection?.setLocalDescription(object : SdpObserver {
                     override fun onSetSuccess() {
                         val json = JSONObject().apply {
-                            put("type", desc.type.canonicalForm())
+                            put("type", fixedVideoDesc.type.canonicalForm())
-                            put("sdp", desc.description)
+                            put("sdp", fixedVideoDesc.description)
                         }
 
                         webSocket.send(json.toString())
@@ -192,7 +361,7 @@ class WebRtcSenderClient(
                     override fun onCreateFailure(error: String) {
                         Timber.e("createOffer failed: %s", error)
                     }
-                }, desc)
+                }, fixedVideoDesc)
             }
 
             override fun onSetSuccess() {}
@@ -206,6 +375,35 @@ class WebRtcSenderClient(
         }, constraints)
     }
 
+    private fun forceVideoBandwidth(sdp: String): String {
+        val lines = sdp.split("\r\n").toMutableList()
+        val videoStart = lines.indexOfFirst { it.startsWith("m=video") }
+        if (videoStart == -1) {
+            return sdp
+        }
+
+        val videoEnd = lines.drop(videoStart + 1)
+            .indexOfFirst { it.startsWith("m=") }
+            .let { if (it == -1) lines.size else videoStart + 1 + it }
+
+        val bandwidthLine = "b=AS:${VIDEO_MAX_BITRATE_BPS / 1000}"
+        val existingBandwidth = (videoStart until videoEnd).firstOrNull { index ->
+            lines[index].startsWith("b=AS:") || lines[index].startsWith("b=TIAS:")
+        }
+
+        if (existingBandwidth != null) {
+            lines[existingBandwidth] = bandwidthLine
+        } else {
+            val insertAt = (videoStart + 1 until videoEnd).firstOrNull { index ->
+                lines[index].startsWith("a=")
+            } ?: videoEnd
+            lines.add(insertAt, bandwidthLine)
+        }
+
+        Timber.d("Forced video SDP bandwidth: %s", bandwidthLine)
+        return lines.joinToString("\r\n")
+    }
+
     private fun handleSignalingMessage(text: String) {
         val json = JSONObject(text)
 
@@ -246,12 +444,17 @@ class WebRtcSenderClient(
         videoCapturer?.dispose()
         videoSource?.dispose()
         videoTrack?.dispose()
+        videoSender = null
         surfaceTextureHelper?.dispose()
         peerConnection?.close()
         peerConnection?.dispose()
-        factory.dispose()
+        if (::factory.isInitialized) {
+            factory.dispose()
+        }
         eglBase.release()
-        webSocket.close(1000, "close")
+        if (::webSocket.isInitialized) {
+            webSocket.close(1000, "close")
+        }
         okHttpClient.dispatcher.executorService.shutdown()
 
         Timber.d("WebRTC released")

app/src/main/kotlin/com/kimgo/posefit/settings/StreamSettings.kt

@@ -0,0 +1,13 @@
+package com.kimgo.posefit.settings
+
+import com.kimgo.posefit.sender.CameraFacing
+import com.kimgo.posefit.sender.StreamOrientation
+import com.kimgo.posefit.sender.StreamResolution
+
+data class StreamSettings(
+    val signalingUrl: String,
+    val cameraFacing: CameraFacing,
+    val cameraName: String?,
+    val resolution: StreamResolution,
+    val orientation: StreamOrientation,
+)

app/src/main/kotlin/com/kimgo/posefit/settings/StreamSettingsStore.kt

@@ -0,0 +1,51 @@
+package com.kimgo.posefit.settings
+
+import android.content.Context
+import com.kimgo.posefit.sender.CameraFacing
+import com.kimgo.posefit.sender.StreamOrientation
+import com.kimgo.posefit.sender.StreamResolution
+
+class StreamSettingsStore(private val context: Context) {
+
+    private val prefs = context.getSharedPreferences(PREFS_NAME, Context.MODE_PRIVATE)
+
+    fun get(): StreamSettings {
+        val cameraFacingValue = prefs.getString(KEY_CAMERA_FACING, CameraFacing.BACK.name)
+        val orientationValue = prefs.getString(KEY_STREAM_ORIENTATION, StreamOrientation.DEFAULT.name)
+
+        return StreamSettings(
+            signalingUrl = prefs.getString(KEY_SIGNALING_URL, DEFAULT_SIGNALING_URL) ?: DEFAULT_SIGNALING_URL,
+            cameraFacing = runCatching { CameraFacing.valueOf(cameraFacingValue ?: CameraFacing.BACK.name) }
+                .getOrDefault(CameraFacing.BACK),
+            cameraName = prefs.getString(KEY_CAMERA_NAME, null)?.takeIf { it.isNotBlank() },
+            resolution = StreamResolution.from(
+                prefs.getInt(KEY_VIDEO_WIDTH, StreamResolution.DEFAULT.width),
+                prefs.getInt(KEY_VIDEO_HEIGHT, StreamResolution.DEFAULT.height),
+            ),
+            orientation = runCatching { StreamOrientation.valueOf(orientationValue ?: StreamOrientation.DEFAULT.name) }
+                .getOrDefault(StreamOrientation.DEFAULT),
+        )
+    }
+
+    fun save(settings: StreamSettings) {
+        prefs.edit()
+            .putString(KEY_SIGNALING_URL, settings.signalingUrl)
+            .putString(KEY_CAMERA_FACING, settings.cameraFacing.name)
+            .putString(KEY_CAMERA_NAME, settings.cameraName)
+            .putInt(KEY_VIDEO_WIDTH, settings.resolution.width)
+            .putInt(KEY_VIDEO_HEIGHT, settings.resolution.height)
+            .putString(KEY_STREAM_ORIENTATION, settings.orientation.name)
+            .apply()
+    }
+
+    companion object {
+        const val PREFS_NAME = "posefit_prefs"
+        const val KEY_SIGNALING_URL = "signaling_url"
+        const val KEY_CAMERA_FACING = "camera_facing"
+        const val KEY_CAMERA_NAME = "camera_name"
+        const val KEY_VIDEO_WIDTH = "video_width"
+        const val KEY_VIDEO_HEIGHT = "video_height"
+        const val KEY_STREAM_ORIENTATION = "stream_orientation"
+        const val DEFAULT_SIGNALING_URL = "ws://192.168.2.6:8765"
+    }
+}

app/src/main/kotlin/com/kimgo/posefit/ui/PosefitApp.kt

@@ -0,0 +1,376 @@
+package com.kimgo.posefit.ui
+
+import android.content.Context
+import androidx.compose.foundation.layout.Arrangement
+import androidx.compose.foundation.layout.Box
+import androidx.compose.foundation.layout.Column
+import androidx.compose.foundation.layout.ColumnScope
+import androidx.compose.foundation.layout.Row
+import androidx.compose.foundation.layout.Spacer
+import androidx.compose.foundation.layout.fillMaxSize
+import androidx.compose.foundation.layout.fillMaxWidth
+import androidx.compose.foundation.layout.height
+import androidx.compose.foundation.layout.padding
+import androidx.compose.foundation.rememberScrollState
+import androidx.compose.foundation.verticalScroll
+import androidx.compose.material3.Button
+import androidx.compose.material3.DropdownMenu
+import androidx.compose.material3.DropdownMenuItem
+import androidx.compose.material3.MaterialTheme
+import androidx.compose.material3.OutlinedButton
+import androidx.compose.material3.Text
+import androidx.compose.material3.TextButton
+import androidx.compose.material3.TextField
+import androidx.compose.runtime.Composable
+import androidx.compose.runtime.getValue
+import androidx.compose.runtime.mutableStateOf
+import androidx.compose.runtime.remember
+import androidx.compose.runtime.setValue
+import androidx.compose.ui.Alignment
+import androidx.compose.ui.Modifier
+import androidx.compose.ui.text.font.FontWeight
+import androidx.compose.ui.unit.dp
+import com.kimgo.posefit.sender.CameraCatalog
+import com.kimgo.posefit.sender.CameraFacing
+import com.kimgo.posefit.sender.CameraOption
+import com.kimgo.posefit.sender.StreamResolution
+import com.kimgo.posefit.settings.StreamSettings
+
+@Composable
+fun PosefitApp(
+    context: Context,
+    initialSettings: StreamSettings,
+    isInitiallyStreaming: Boolean,
+    onStartStreaming: (StreamSettings, (Boolean) -> Unit) -> Unit,
+    onStopStreaming: () -> Unit,
+    onSaveSettings: (StreamSettings) -> Unit,
+    onApplyOrientation: (StreamSettings) -> Unit,
+) {
+    var screen by remember { mutableStateOf(AppScreen.HOME) }
+    var isStreaming by remember { mutableStateOf(isInitiallyStreaming) }
+    var settings by remember { mutableStateOf(initialSettings) }
+
+    when (screen) {
+        AppScreen.HOME -> HomeScreen(
+            isStreaming = isStreaming,
+            settings = settings,
+            onToggleStreaming = {
+                if (isStreaming) {
+                    onStopStreaming()
+                    isStreaming = false
+                } else {
+                    onSaveSettings(settings)
+                    onApplyOrientation(settings)
+                    onStartStreaming(settings) { granted ->
+                        isStreaming = granted
+                    }
+                }
+            },
+            onOpenSettings = { screen = AppScreen.SETTINGS },
+            onRotate = {
+                val updated = settings.copy(orientation = settings.orientation.next())
+                settings = updated
+                onSaveSettings(updated)
+                onApplyOrientation(updated)
+            },
+        )
+
+        AppScreen.SETTINGS -> SettingsScreen(
+            context = context,
+            initialSettings = settings,
+            isStreaming = isStreaming,
+            onSave = { updated ->
+                settings = updated
+                onSaveSettings(updated)
+                screen = AppScreen.HOME
+            },
+            onBack = { screen = AppScreen.HOME },
+        )
+    }
+}
+
+@Composable
+private fun HomeScreen(
+    isStreaming: Boolean,
+    settings: StreamSettings,
+    onToggleStreaming: () -> Unit,
+    onOpenSettings: () -> Unit,
+    onRotate: () -> Unit,
+) {
+    Box(
+        modifier = Modifier
+            .fillMaxSize()
+            .padding(24.dp),
+    ) {
+        Row(
+            modifier = Modifier.align(Alignment.TopEnd),
+            horizontalArrangement = Arrangement.spacedBy(8.dp),
+        ) {
+            TextButton(onClick = onRotate) {
+                Text("旋转")
+            }
+            TextButton(
+                onClick = onOpenSettings,
+                enabled = !isStreaming,
+            ) {
+                Text("设置")
+            }
+        }
+
+        Column(
+            modifier = Modifier
+                .fillMaxSize()
+                .padding(horizontal = 24.dp),
+            verticalArrangement = Arrangement.Center,
+            horizontalAlignment = Alignment.CenterHorizontally,
+        ) {
+            Text(
+                text = "PoseFit",
+                style = MaterialTheme.typography.headlineLarge,
+                fontWeight = FontWeight.Bold,
+                color = MaterialTheme.colorScheme.primary,
+            )
+            Spacer(modifier = Modifier.height(12.dp))
+            Text(
+                text = if (isStreaming) {
+                    "正在推流：${settings.resolution.label} ${settings.orientation.label}"
+                } else {
+                    "未推流：${settings.resolution.label} ${settings.orientation.label}"
+                },
+                style = MaterialTheme.typography.titleMedium,
+                color = if (isStreaming) {
+                    MaterialTheme.colorScheme.primary
+                } else {
+                    MaterialTheme.colorScheme.onSurfaceVariant
+                },
+            )
+            Spacer(modifier = Modifier.height(24.dp))
+            Button(
+                onClick = onToggleStreaming,
+                modifier = Modifier
+                    .fillMaxWidth(0.72f)
+                    .height(56.dp),
+            ) {
+                Text(if (isStreaming) "停止推流" else "开始推流")
+            }
+        }
+    }
+}
+
+@Composable
+private fun SettingsScreen(
+    context: Context,
+    initialSettings: StreamSettings,
+    isStreaming: Boolean,
+    onSave: (StreamSettings) -> Unit,
+    onBack: () -> Unit,
+) {
+    var url by remember { mutableStateOf(initialSettings.signalingUrl) }
+    var cameraFacing by remember { mutableStateOf(initialSettings.cameraFacing) }
+    var selectedCameraName by remember { mutableStateOf(initialSettings.cameraName) }
+    var selectedResolution by remember { mutableStateOf(initialSettings.resolution) }
+    var cameraMenuExpanded by remember { mutableStateOf(false) }
+    var resolutionMenuExpanded by remember { mutableStateOf(false) }
+    val cameraOptions = remember { runCatching { CameraCatalog.listOptions(context) }.getOrDefault(emptyList()) }
+    val selectedCameraOption = remember(selectedCameraName, cameraOptions) {
+        resolveSelectedCameraOption(cameraOptions, selectedCameraName)
+    }
+    val availableResolutions = remember(selectedCameraOption) {
+        selectedCameraOption?.supportedResolutions
+            ?.takeIf { it.isNotEmpty() }
+            ?: StreamResolution.PRESETS
+    }
+    val effectiveResolution = remember(availableResolutions, selectedResolution) {
+        chooseResolution(availableResolutions, selectedResolution)
+    }
+    val selectedCameraLabel = remember(selectedCameraName, selectedCameraOption) {
+        if (selectedCameraName.isNullOrBlank()) {
+            "自动选择后置最广角"
+        } else {
+            selectedCameraOption?.label ?: "自动选择后置最广角"
+        }
+    }
+
+    Column(
+        modifier = Modifier
+            .fillMaxSize()
+            .verticalScroll(rememberScrollState())
+            .padding(horizontal = 28.dp, vertical = 20.dp),
+        verticalArrangement = Arrangement.spacedBy(16.dp),
+    ) {
+        Row(
+            modifier = Modifier.fillMaxWidth(),
+            horizontalArrangement = Arrangement.SpaceBetween,
+            verticalAlignment = Alignment.CenterVertically,
+        ) {
+            Text(
+                text = "设置",
+                style = MaterialTheme.typography.headlineSmall,
+                fontWeight = FontWeight.Bold,
+            )
+            TextButton(onClick = onBack) {
+                Text("返回")
+            }
+        }
+
+        TextField(
+            value = url,
+            onValueChange = { url = it },
+            label = { Text("WS 服务器地址") },
+            modifier = Modifier.fillMaxWidth(),
+            singleLine = true,
+            enabled = !isStreaming,
+        )
+
+        SettingGroup(title = "摄像头") {
+            Box(modifier = Modifier.fillMaxWidth()) {
+                OutlinedButton(
+                    onClick = { cameraMenuExpanded = true },
+                    enabled = !isStreaming,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .height(48.dp),
+                ) {
+                    Text(selectedCameraLabel, maxLines = 1)
+                }
+                DropdownMenu(
+                    expanded = cameraMenuExpanded,
+                    onDismissRequest = { cameraMenuExpanded = false },
+                ) {
+                    DropdownMenuItem(
+                        text = { Text("自动选择后置最广角") },
+                        onClick = {
+                            cameraFacing = CameraFacing.BACK
+                            selectedCameraName = null
+                            selectedResolution = chooseResolution(
+                                resolveSelectedCameraOption(cameraOptions, null)
+                                    ?.supportedResolutions
+                                    ?.takeIf { it.isNotEmpty() }
+                                    ?: StreamResolution.PRESETS,
+                                selectedResolution,
+                            )
+                            cameraMenuExpanded = false
+                        },
+                    )
+                    cameraOptions.forEach { option ->
+                        DropdownMenuItem(
+                            text = { Text(option.label) },
+                            onClick = {
+                                cameraFacing = option.facing
+                                selectedCameraName = option.name
+                                selectedResolution = chooseResolution(
+                                    option.supportedResolutions.takeIf { it.isNotEmpty() }
+                                        ?: StreamResolution.PRESETS,
+                                    selectedResolution,
+                                )
+                                cameraMenuExpanded = false
+                            },
+                        )
+                    }
+                }
+            }
+        }
+
+        SettingGroup(title = "推流分辨率") {
+            Box(modifier = Modifier.fillMaxWidth()) {
+                OutlinedButton(
+                    onClick = { resolutionMenuExpanded = true },
+                    enabled = !isStreaming,
+                    modifier = Modifier
+                        .fillMaxWidth()
+                        .height(48.dp),
+                ) {
+                    Text(effectiveResolution.label, maxLines = 1)
+                }
+                DropdownMenu(
+                    expanded = resolutionMenuExpanded,
+                    onDismissRequest = { resolutionMenuExpanded = false },
+                ) {
+                    availableResolutions.forEach { resolution ->
+                        DropdownMenuItem(
+                            text = { Text(resolution.label) },
+                            onClick = {
+                                selectedResolution = resolution
+                                resolutionMenuExpanded = false
+                            },
+                        )
+                    }
+                }
+            }
+        }
+
+        Button(
+            onClick = {
+                onSave(
+                    StreamSettings(
+                        signalingUrl = url.trim(),
+                        cameraFacing = cameraFacing,
+                        cameraName = selectedCameraName,
+                        resolution = effectiveResolution,
+                        orientation = initialSettings.orientation,
+                    )
+                )
+            },
+            modifier = Modifier
+                .fillMaxWidth()
+                .height(52.dp),
+        ) {
+            Text("保存设置")
+        }
+    }
+}
+
+@Composable
+private fun SettingGroup(
+    title: String,
+    content: @Composable ColumnScope.() -> Unit,
+) {
+    Column(
+        modifier = Modifier.fillMaxWidth(),
+        verticalArrangement = Arrangement.spacedBy(8.dp),
+    ) {
+        Text(
+            text = title,
+            style = MaterialTheme.typography.titleSmall,
+            color = MaterialTheme.colorScheme.onSurfaceVariant,
+        )
+        content()
+    }
+}
+
+private fun resolveSelectedCameraOption(
+    cameraOptions: List<CameraOption>,
+    selectedCameraName: String?,
+): CameraOption? {
+    if (!selectedCameraName.isNullOrBlank()) {
+        return cameraOptions.firstOrNull { it.name == selectedCameraName }
+    }
+
+    return cameraOptions
+        .filter { it.facing == CameraFacing.BACK }
+        .minByOrNull { it.minFocalLength ?: Float.MAX_VALUE }
+        ?: cameraOptions.firstOrNull()
+}
+
+private fun chooseResolution(
+    availableResolutions: List<StreamResolution>,
+    currentResolution: StreamResolution,
+): StreamResolution {
+    if (availableResolutions.isEmpty()) {
+        return StreamResolution.DEFAULT
+    }
+    if (currentResolution in availableResolutions) {
+        return currentResolution
+    }
+    if (StreamResolution.DEFAULT in availableResolutions) {
+        return StreamResolution.DEFAULT
+    }
+    return availableResolutions.minByOrNull {
+        kotlin.math.abs((it.width * it.height) - (StreamResolution.DEFAULT.width * StreamResolution.DEFAULT.height))
+    } ?: availableResolutions.first()
+}
+
+private enum class AppScreen {
+    HOME,
+    SETTINGS,
+}