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• Can VideoView be detach and reattached without stopping the stream ?

  1er juin 2015, par Thierry-Dimitri Roy

  I’m building an app where the user clicks on a button to show a video full screen. Initially the video is attached to a view inside a ViewPager. To be able to show it fullscreen I detach it from its parent and reattach it to the root view. This works fine, except when the video is switched to fullscreen while playing. When I detach a playing VideoView it just stop and I need to restart it. This is not acceptable since the video starts buffering before resume. Here the part of the code where the detach is done :

      final ViewGroup parent = (ViewGroup) findViewById(R.id.parent);
  
  
  
      final ViewGroup root = (ViewGroup) findViewById(R.id.root);
  
  
  
      Button b = (Button) findViewById(R.id.button);
  
      b.setOnClickListener(new OnClickListener() {
  
  
  
          @Override
  
          public void onClick(View v) {
  
              parent.removeView(mVideoView);
  
  
  
              LayoutParams lp = new FrameLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.MATCH_PARENT);
  
              root.addView(mVideoView, lp);
  
          }
  
      });

  Depending of the device, I have a different log error. Probably because the actual video player is provided by the manufacturer and not the Android SDK. Here are the error logs for a Nexus 7 :

  10-30 20:26:18.618: D/NvOsDebugPrintf(124): NvMMDecTVMRDestroyParser Begin 
  
  10-30 20:26:18.618: D/NvOsDebugPrintf(124): --------- Closing TVMR Frame Delivery Thread -------------
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): ------- NvAvpClose -------
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): NvMMDecTVMRDestroyParser Done 
  
  10-30 20:26:18.678: D/NvOsDebugPrintf(124): NvMMLiteTVMRDecPrivateClose Done 

  I haven’t been able to detach the video without stopping it. I tried using SurfaceView or TextureView without success.

  I also tried finding a third party video player. I found a commercial one (http://www.vitamio.org/) that I can’t really use for business reason. I found an open source one, that hasn’t been updated in the last year (https://code.google.com/p/dolphin-player/).

  I’m currently targeting Android 4.2 or better on tablet only.

  ---

  Note that the ViewPager is not fullscreen. So I can’t use LayoutParams to make the video fullscreen. I need to remove the VideoView from the parent in the ViewPager and add it to the root view to be able to show it fullscreen.

  The URL I’m testing with : http://bellvps1.cpl.delvenetworks.com/media/e1b3e24ecb944abd8f4ed823a0b76ddc/68f78d35296243bfb46d2418f03f2fd0/bande-annonce---the-secret-life-of-walter-mitty-1-9efcc5c6e52ac07a3edf84a1b21967995b7796a2.m3u8

• How do I convert ADPCM to PCM using FFmpeg ?

  26 janvier 2013, par mystafer

  I have a video feed that sends me audio using the ADPCM codec. However, android only supports PCM format. How can I convert the ADPCM audio feed into a PCM audio feed ?

  The answer to this may be similar to the answer to this question.

  I have successfully decoded the frame with this code :

  int len = avcodec_decode_audio4(pAudioCodecCtx, pAudioFrame, &frameFinished, &packet);

  Is the secret here to use a reverse encode function ?

  Here is what I have so far in my audio decode function :

  if(packet_queue_get(env, javaThread, pAudioPacketQueue, &packet, 1) < 0) {
  
      LOGE("audio - after get packet failed");
  
      return;
  
  }
  
  LOGD("Dequeued audio packet");
  
  
  
  // calculate frame size
  
  int frameSize;
  
  if (pPcmAudioCodecCtx->frame_size) {
  
      frameSize = pPcmAudioCodecCtx->frame_size;
  
  } else {
  
      /* if frame_size is not set, the number of samples must be
  
       * calculated from the buffer size */
  
      int64_t nb_samples = (int64_t)AUDIO_PCM_OUTBUFF_SIZE * 8 /
  
              (av_get_bits_per_sample(pPcmAudioCodecCtx->codec_id) *
  
                      pPcmAudioCodecCtx->channels);
  
      frameSize = nb_samples;
  
  }
  
  
  
  int pcmBytesPerSample = av_get_bytes_per_sample(pPcmAudioCodecCtx->sample_fmt);
  
  int pcmFrameBytes = frameSize * pcmBytesPerSample * pPcmAudioCodecCtx->channels;
  
  
  
  uint8_t *pDataStart = packet.data;
  
  while(packet.size > 0) {
  
      int len = avcodec_decode_audio4(pAudioCodecCtx, pAudioFrame, &frameFinished, &packet);
  
      LOGD("Decoded ADPCM frame");
  
  
  
      if (len < 0) {
  
          LOGE("Error while decoding audio");
  
          return;
  
      }
  
  
  
      if (frameFinished) {
  
          // store frame data in FIFO buffer
  
          uint8_t *inputBuffer = pAudioFrame->data[0];
  
          int inputBufferSize = pAudioFrame->linesize[0];
  
          av_fifo_generic_write(fifoBuffer, inputBuffer, inputBufferSize, NULL);
  
          LOGD("Added ADPCM frame to FIFO buffer");
  
  
  
          // check if fifo buffer has enough data for a PCM frame
  
          while (av_fifo_size(fifoBuffer) >= pcmFrameBytes) {
  
              LOGI("PCM frame data in FIFO buffer");
  
  
  
              // read frame's worth of data from FIFO buffer
  
              av_fifo_generic_read(fifoBuffer, pAudioPcmOutBuffer, pcmFrameBytes, NULL);
  
              LOGD("Read data from FIFO buffer into pcm frame");
  
  
  
  
  
              avcodec_get_frame_defaults(pPcmAudioFrame);
  
              LOGD("Got frame defaults");
  
  
  
              pPcmAudioFrame->nb_samples = pcmFrameBytes / (pPcmAudioCodecCtx->channels *
  
                      pcmBytesPerSample);
  
  
  
              avcodec_fill_audio_frame(pPcmAudioFrame, pPcmAudioCodecCtx->channels,
  
                      pPcmAudioCodecCtx->sample_fmt,
  
                      pAudioPcmOutBuffer, pcmFrameBytes, 1);
  
              LOGD("Filled frame audio with data");
  
  
  
              // fill audio play buffer
  
              int dataSize = pPcmAudioFrame->linesize[0];
  
              LOGD("Data to output: %d", dataSize);
  
              jbyteArray audioPlayBuffer = (jbyteArray) env->GetObjectField(ffmpegCtx, env->GetFieldID(cls, "audioPlayBuffer", "[B"));
  
              jbyte *bytes = env->GetByteArrayElements(audioPlayBuffer, NULL);
  
              memcpy(bytes, pPcmAudioFrame->data[0], dataSize);
  
              env->ReleaseByteArrayElements(audioPlayBuffer, bytes, 0);
  
              LOGD("Copied data into Java array");
  
  
  
              env->CallVoidMethod(player, env->GetMethodID(playerCls, "updateAudio", "(I)V"), dataSize);
  
          }

• Decoding video frames and sending them to RabbitMQ using FFmpeg

  28 janvier 2023, par viator

  I've built ffmpeg with AMQP support and tried ffmpeg -i /videos/episode.mp4 -f mpegts amqp://localhost which apparently works. But AFAIK mpegts has some muxing overhead, so I don't really know how it splits stream into messages.

  


  Is it possible to decode all the frames from a video and send them one-by-one in some format (say, JPEG or PNG) to RabbitMQ ?