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• how do i create a stereo mp3 file with latest version of ffmpeg ?

  17 juin 2016, par Sean

  I’m updating my code from the older version of ffmpeg (53) to the newer (54/55). Code that did work has now been deprecated or removed so i’m having problems updating it.

  Previously I could create a stereo MP3 file using a sample format called :

  SAMPLE_FMT_S16

  That matched up perfectly with my source stream. This has now been replace with

  AV_SAMPLE_FMT_S16

  Which works fine for mono recordings but when I try to create a stereo MP3 file it bugs out at avcodec_open2 with :

  "Specified sample_fmt is not supported."

  Through trial and error I’ve found that using

  AV_SAMPLE_FMT_S16P

  ...is accepted by avcodec_open2 but when I get through and create the MP3 file the sound is very distorted - it sounds about 2 octaves lower than usual with a massive hum in the background - here’s an example recording :

  http://hosting.ispyconnect.com/example.mp3

  I’ve been told by the ffmpeg guys that this is because I now need to manually deinterleave my byte stream before calling :

  avcodec_fill_audio_frame

  How do I do that ? I’ve tried using the swrescale library without success and i’ve tried manually feeding in L/R data into avcodec_fill_audio_frame but the results i’m getting are sounding exactly the same as without interleaving.

  Here is my code for encoding :

  void add_audio_sample( AudioWriterPrivateData^ data, BYTE* soundBuffer, int soundBufferSize)
  
  {
  
      libffmpeg::AVCodecContext* c = data->AudioStream->codec;
  
      memcpy(data->AudioBuffer + data->AudioBufferSizeCurrent,  soundBuffer, soundBufferSize);
  
      data->AudioBufferSizeCurrent += soundBufferSize;
  
      uint8_t* pSoundBuffer = (uint8_t *)data->AudioBuffer;
  
      DWORD nCurrentSize    = data->AudioBufferSizeCurrent;
  
  
  
      libffmpeg::AVFrame *frame;
  
  
  
      int got_packet;
  
      int ret;
  
      int size = libffmpeg::av_samples_get_buffer_size(NULL, c->channels,
  
                                                data->AudioInputSampleSize,
  
                                                c->sample_fmt, 1);
  
  
  
      while( nCurrentSize >= size)    {
  
  
  
          frame=libffmpeg::avcodec_alloc_frame();
  
          libffmpeg::avcodec_get_frame_defaults(frame);
  
  
  
          frame->nb_samples = data->AudioInputSampleSize;
  
  
  
          ret = libffmpeg::avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt, pSoundBuffer, size, 1);
  
          if (ret<0)
  
          {
  
              throw gcnew System::IO::IOException("error filling audio");
  
          }
  
          //audio_pts = (double)audio_st->pts.val * audio_st->time_base.num / audio_st->time_base.den;
  
  
  
          libffmpeg::AVPacket pkt = { 0 };
  
          libffmpeg::av_init_packet(&pkt);
  
  
  
          ret = libffmpeg::avcodec_encode_audio2(c, &pkt, frame, &got_packet);
  
  
  
          if (ret<0)
  
                  throw gcnew System::IO::IOException("error encoding audio");
  
          if (got_packet) {
  
              pkt.stream_index = data->AudioStream->index;
  
  
  
              if (pkt.pts != AV_NOPTS_VALUE)
  
                  pkt.pts = libffmpeg::av_rescale_q(pkt.pts, c->time_base, c->time_base);
  
              if (pkt.duration > 0)
  
                  pkt.duration = av_rescale_q(pkt.duration, c->time_base, c->time_base);
  
  
  
              pkt.flags |= AV_PKT_FLAG_KEY;
  
  
  
              if (libffmpeg::av_interleaved_write_frame(data->FormatContext, &pkt) != 0)
  
                      throw gcnew System::IO::IOException("unable to write audio frame.");
  
  
  
  
  
          }
  
          nCurrentSize -= size;  
  
          pSoundBuffer += size;   
  
      }
  
      memcpy(data->AudioBuffer, data->AudioBuffer + data->AudioBufferSizeCurrent - nCurrentSize, nCurrentSize);
  
      data->AudioBufferSizeCurrent = nCurrentSize; 
  
  
  
  }

  Would love to hear any ideas - I’ve been trying to get this working for 3 days now :(

• JavaCV FFMpegRecorder streams video not displayed properly

  20 août 2015, par Mo Adel

  I have been in loop for 5 days trying to implement JavaCV with FFmpegRecorder, Having figured out that i have to use OpenCvFrameConverter to conert IplImage to frame, I finally managed to see some video over the stream. but now the problem seems to be that the audio works perfect and clearly, but video is not displayed properly.

  

  Beside that there is a massive delay on the stream, well over 40sec, when i thought RTMP had 2-4sec delay,

  Here is some code :

  FFmpegFrameRecorder Initialization

  recorder = new FFmpegFrameRecorder(ffmpeg_link, screenWidth, screenHeight, 1);
  
      recorder.setFormat("flv");
  
      recorder.setSampleRate(44100);
  
      recorder.setAudioCodec(avcodec.AV_CODEC_ID_AAC);
  
      recorder.setVideoCodec(avcodec.AV_CODEC_ID_FLV1);// AV_CODEC_ID_FLV1
  
      recorder.setVideoOption("preset", "ultrafast"); 
  
      recorder.setFrameRate(30);

  And here is my SurfaceChanged and PreviewFrame Methods

   public void surfaceChanged(SurfaceHolder holder, int format, int width, int height) {
  
  
  
          Camera.Parameters camParams = mCamera.getParameters();
  
          List sizes = camParams.getSupportedPreviewSizes();         
  
  
  
          android.hardware.Camera.Size z = getOptimalPreviewSize(sizes, screenWidth, screenHeight);
  
          int imageWidth = z.width;
  
          int imageHeight = z.height;
  
          camParams.setPreviewSize(imageWidth, imageHeight);
  
          mCamera.setParameters(camParams);
  
  
  
          for(int[] arr : camParams.getSupportedPreviewFpsRange()){
  
              Log.e(LOG_TAG, "Supported range: " + arr[0] + " - " + arr[1]);
  
          }
  
  
  
          Camera.Parameters framerateAttempts = mCamera.getParameters();
  
          camParams.setPreviewFrameRate(frameRate);
  
          Log.v(LOG_TAG,"Preview Framerate: " + camParams.getPreviewFrameRate());
  
          Display display = ((WindowManager)getSystemService(WINDOW_SERVICE)).getDefaultDisplay();
  
  
  
          if(display.getRotation() == Surface.ROTATION_0)
  
          {
  
              mCamera.setDisplayOrientation(90);
  
          }
  
  
  
          if(display.getRotation() == Surface.ROTATION_90)
  
          {
  
          }
  
  
  
          if(display.getRotation() == Surface.ROTATION_180)
  
          {
  
          }
  
  
  
          if(display.getRotation() == Surface.ROTATION_270)
  
          {
  
              mCamera.setDisplayOrientation(180);
  
          }
  
          camParams.setFocusMode(Parameters.FOCUS_MODE_CONTINUOUS_PICTURE);
  
          mCamera.setParameters(framerateAttempts);
  
  
  
          startPreview();
  
      }
  
  
  
   @Override
  
      public void onPreviewFrame(byte[] data, Camera camera) {
  
          /* get video data */
  
          if (yuvIplimage != null && recording) {
  
              yuvIplimage.getByteBuffer().put(data);
  
  
  
              Log.v(LOG_TAG,"Writing Frame");
  
              try {
  
                  long t = 1000 * (System.currentTimeMillis() - startTime);
  
                  if (t > recorder.getTimestamp()) {
  
                      recorder.setTimestamp(t);
  
                  }
  
  
  
                  OpenCVFrameConverter.ToIplImage converterToMat = new OpenCVFrameConverter.ToIplImage();
  
                  Frame f = converterToMat.convert(yuvIplimage);
  
                  recorder.record(f);
  
              } catch (FFmpegFrameRecorder.Exception e) {
  
                  Log.v(LOG_TAG,e.getMessage());
  
                  e.printStackTrace();
  
              }
  
          }
  
      }

• Merge three media files (Video and image) into one

  8 avril 2019, par Munshi Arif Rashid

  I have total three separated media files. The first file is 1600X900 .mp4 file which will be placed at the left side of the screen (Height size will be full screen and width will cover two-thirds of the screen). The second file is 640X480 .png file which will be placed at the upper right of the screen (Height size will be half of the screen and width will cover one-third of the screen). The third file is 640X480 .webm file which will be placed at the lower right of the screen (Height size will be half of screen and width will cover one-thirds of the screen). I want to merge these three files in a single screen as mentioned above. Can anyone help me ? Thanks