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• FFmpeg and types of samples

  23 juillet 2015, par Kyborg2011

  Decoded audio using FFmpeg (function avcodec_decode_audio3) and try to reproduce it through Audiotrack in Android. When playing I hear some growling. No music. On the forums advised that the problem with the samples. Question : how to solve this problem, if it is associated with a mismatch of types of samples ? Code decoding :

          while (av_read_frame(pFormatCtx, &packet)>= 0) {
  
              if (aCodecCtx->codec_type == AVMEDIA_TYPE_AUDIO) {
  
                          int data_size = AVCODEC_MAX_AUDIO_FRAME_SIZE * 2;
  
                          int size=packet.size;
  
   int decoded = 0;
  
                          while(size > 0) {
  
                                  int len = avcodec_decode_audio3(aCodecCtx, (uint16_t *) pAudioBuffer, &data_size, &packet);
  
  
  
  
  
                                  jbyte *bytes = (*env)->GetByteArrayElements(env, array, NULL);
  
                                  memcpy(bytes + decoded, (uint16_t *) pAudioBuffer, len);
  
                                  (*env)->ReleaseByteArrayElements(env, array, bytes, 0);
  
  
  
                                  (*env)->CallStaticVoidMethod(env, cls, mid, array);
  
  
  
  
  
                                  size -= len;
  
                                  decoded += len;
  
                                  }
  
              }
  
  
  
       }

  Java code :

      protected void onCreate(Bundle savedInstanceState) {
  
          super.onCreate(savedInstanceState);
  
          setContentView(R.layout.main);
  
  
  
           int bufSize = AudioTrack.getMinBufferSize(44100,                                AudioFormat.CHANNEL_CONFIGURATION_MONO, 
  
                          AudioFormat.ENCODING_PCM_16BIT);
  
          track = new AudioTrack(AudioManager.STREAM_MUSIC, 44100, AudioFormat.CHANNEL_CONFIGURATION_MONO, 
  
                      AudioFormat.ENCODING_PCM_16BIT, bufSize, AudioTrack.MODE_STREAM);
  
          track.play();
  
  
  
              bytes = new byte[bufSize];
  
              int res = main(2, "/sdcard/muzika_iz_reklami_bmw_5_series_-_bmw_5_series.mp3", bytes);
  
  
  
  
  
              System.out.println(res);
  
      }
  
      private static void play(byte[] play) {
  
  
  
          track.write(play, 0, play.length);
  
      }

  How to solve this problem ?
  P.S. The file itself is checked - the standard player plays. Format : mp3.

• Streaming jpegs live to iphone app

  14 février 2012, par Raven

  Im progressing through taking the depth camera feed from my kinect and streaming it to my iphone app. I have got to stage of being able save jpegs for every frame created from the kinect depth image (30 fps) and save them to the local disk. I have than been able to convert this to mpeg with ffmpeg.

  My question is now how can I view this live on my iphone ? Basically I want to view it live on the iphone as you are seeing it coming from the kinect.

  Should I use http live streaming and use the segmenter to use apples HttpLiveStreaming functionality ? Or can I stream the raw jpeg image files up in some way as they are saved to disk and than just cycle the images on the phone as they go ?

  Im wondering how video conferencing is achieved on the iphone (facetime/skype etc) ? because I'd prefer that it wasnt played inside the video player, just want to display live content on the screen as it happens.

  Any ideas ? Thanks in advance

• Recording application output to video using FFmpeg (or similar)

  15 décembre 2011, par John

  We have a requirement to lets users record a video of our 3D application. I can already grab the individual rendered frames so this question is specifically about how to write frames into a video file.

  I don't think writing each frame as a separate file and post-processing is a workable option.

  I can look at options to record to a simple video file for later optimising/encoding, or writing directly to a sensibly encoded format.

  FFmpeg was suggested in another post but it looks a bit daunting to me. Is it the best option, if not what can be suggested ? We can work with LGPL but not full GPL.

  We're working on Windows (Win32 not MFC) in C++. Sample/pseudo code with your recommended library is very much appreciated... basically after how to do 3 functions :

  • startRecording() does whatever initialization is needed
  • recordFrame() takes pointer to frame data and encodes it, ideally with timing data
  • endRecording() finalizes the video file, shuts down video system, etc