Stabilize Android secondary low-latency video playback

app/videostreaming/android/lowlagdecoder.cpp

@@ -59,36 +59,45 @@ LowLagDecoder::LowLagDecoder(JNIEnv* env, bool verboseLogging, std::string logTa
 
 void LowLagDecoder::setOutputSurface(JNIEnv* env,jobject surface){
     USE_SW_DECODER_INSTEAD=false;
-    if(surface==nullptr){
-        //MLOGD<<"Set output surface to null";
-        //assert(decoder.window!=nullptr);
-        if(decoder.window== nullptr){
-            //MLOGD<<"Decoder window is already null";
-            return;
-        }
+
+    auto releaseDecoderResources = [this]() {
         std::lock_guard<std::mutex> lock(mMutexInputPipe);
         inputPipeClosed=true;
         if(decoder.configured){
-            AMediaCodec_stop(decoder.codec);
-            AMediaCodec_delete(decoder.codec);
-            decoder.codec=nullptr;
+            if (decoder.codec) {
+                AMediaCodec_stop(decoder.codec);
+                AMediaCodec_delete(decoder.codec);
+                decoder.codec=nullptr;
+            }
             mKeyFrameFinder.reset();
             decoder.configured=false;
-            if(mCheckOutputThread->joinable()){
+            if(mCheckOutputThread && mCheckOutputThread->joinable()){
                 mCheckOutputThread->join();
-                mCheckOutputThread.reset();
             }
+            mCheckOutputThread.reset();
+        }
+        if (decoder.window) {
+            ANativeWindow_release(decoder.window);
+            decoder.window=nullptr;
         }
-        ANativeWindow_release(decoder.window);
-        decoder.window=nullptr;
         resetStatistics();
-    }else{
-        // Throw warning if the surface is set without clearing it first
-        assert(decoder.window==nullptr);
-        decoder.window=ANativeWindow_fromSurface(env,surface);
-        // open the input pipe - now the decoder will start as soon as enough data is available
-        inputPipeClosed=false;
+    };
+
+    if(surface==nullptr){
+        if(decoder.window== nullptr){
+            return;
+        }
+        releaseDecoderResources();
+        return;
     }
+
+    if(decoder.window!=nullptr){
+        releaseDecoderResources();
+    }
+
+    decoder.window=ANativeWindow_fromSurface(env,surface);
+    // open the input pipe - now the decoder will start as soon as enough data is available
+    inputPipeClosed=false;
 }
 
 void LowLagDecoder::registerOnDecoderRatioChangedCallback(DECODER_RATIO_CHANGED decoderRatioChangedC) {
@@ -167,6 +176,12 @@ void LowLagDecoder::configureStartDecoder(){
         //MLOGD<<"Created decoder "<<std::string(name);
         //AMediaCodec_releaseName(decoder.codec,name);
     }
+    if (decoder.codec== nullptr) {
+        MLOGD<<"Cannot create decoder";
+        //set csd-0 and csd-1 back to 0, maybe they were just faulty but we have better luck with the next ones
+        mKeyFrameFinder.reset();
+        return;
+    }
     AMediaFormat* format=AMediaFormat_new();
     AMediaFormat_setString(format,AMEDIAFORMAT_KEY_MIME,MIME.c_str());
     if(IS_H265){

app/videostreaming/android/qandroidsecondarymediaplayer.cpp

@@ -33,15 +33,18 @@ void QAndroidSecondaryMediaPlayer::setVideoOut(QSurfaceTexture *videoOut)
     if (m_videoOut == videoOut)
         return;
 
-    if (m_videoOut)
+    if (m_videoOut) {
         m_videoOut->disconnect(this);
+        stopPlayback();
+    }
 
     m_videoOut = videoOut;
 
     if (!m_videoOut) {
         stopPlayback();
     } else {
         connect(m_videoOut.data(), &QSurfaceTexture::surfaceTextureChanged, this, [this] {
+            stopPlayback();
             m_pendingPlayback = true;
             tryStartPlayback();
         });
@@ -90,6 +93,16 @@ void QAndroidSecondaryMediaPlayer::tryStartPlayback()
     if (!m_videoOut)
         return;
 
+    if (m_playbackRunning) {
+        m_pendingPlayback = false;
+        return;
+    }
+
+    const auto streamConfig = resolveStreamConfig();
+    if (!streamConfig) {
+        return;
+    }
+
     const auto streamConfig = resolveStreamConfig();
     if (!streamConfig) {
         return;
@@ -170,6 +183,7 @@ void QAndroidSecondaryMediaPlayer::startPlaybackOnAndroidThread(const QAndroidJn
     });
 
     m_pendingPlayback = false;
+    m_playbackRunning = true;
 }
 
 void QAndroidSecondaryMediaPlayer::stopPlayback()
@@ -188,4 +202,5 @@ void QAndroidSecondaryMediaPlayer::stopPlayback()
 
     m_activeConfig.reset();
     m_pendingPlayback = false;
+    m_playbackRunning = false;
 }

app/videostreaming/android/qandroidsecondarymediaplayer.h

@@ -41,6 +41,7 @@ class QAndroidSecondaryMediaPlayer : public QObject
 
     QPointer<QSurfaceTexture> m_videoOut;
     bool m_pendingPlayback = false;
+    bool m_playbackRunning = false;
     std::optional<QOpenHDVideoHelper::VideoStreamConfigXX> m_activeConfig;
     std::unique_ptr<LowLagDecoder> m_lowLagDecoder;
     std::unique_ptr<GstRtpReceiver> m_receiver;