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• how to use guardianproject's android ffmpeg library ?

  21 octobre 2013, par Blaze Tama

  First, this is my first time "playing" with ffmpeg, so please bear with me.

  Generally, i dont understand ffmpeg even a little bit. So i did lot, lot of researches (and also trial & error) and i finally found this project and its library

  So i was successfully created the ffmpeg and sox binary file, and i put it in the raw folder at the library project (from the link i shared).

  Now, i want to use the library for my project, but i still cant do it. I tried to use some methods in the FfmpegController like combineAudioAndVideo and more but its not working (yet).

  I dont post the error here since i still do my trial&errors (and the error change regularly) but im getting tired now.

  EDIT

  This is what i did :

  private FfmpegController ffController;
  
  
  
      @Override
  
      protected void onCreate(Bundle savedInstanceState) {
  
          super.onCreate(savedInstanceState);
  
          setContentView(R.layout.activity_main);
  
  
  
          File file = new File(Uri.parse("android.resource://com.my.package/" + R.raw.test).getPath());
  
          try {
  
              ffController = new FfmpegController(this, file);
  
          } catch (FileNotFoundException e) {
  
              // TODO Auto-generated catch block
  
              e.printStackTrace();
  
          } catch (IOException e) {
  
              // TODO Auto-generated catch block
  
              e.printStackTrace();
  
          }
  
  
  
          MediaDesc desc = ffController.combineAudioAndVideo(R.raw.test, R.raw.musictest, "test.mp4", null);
  
      }

  The combineAudioAndVideo always error because wrong parameters. It needs MediaDesc but i dont know how to do it.

  I will be very happy if you can share your working code if you have done the ffmpeg processing with this library.

• FFMpeg(Android) av_read_frame or avcodec_decode_video2 returning same colour

  5 décembre 2012, par Cehm

  I've been experimenting FFMpeg for the past 2 weeks and I'm having a bit of trouble...
  First I've been working with a Galaxy S3, which worked super fine, gave me the best pictures ever but I recently switched to a Galaxy NEXUS which gave me a bunch of problems...

  What I'm doing : I just extract frame from a video

  How I'm doing :

  while(av_read_frame(gFormatCtx, &packet)>=0)
  
          {
  
              // Is this a packet from the video stream?
  
              if(packet.stream_index==videoStream)
  
              {
  
                  // Decode video frame
  
                  avcodec_decode_video2(gVideoCodecCtx, pFrame, &frameFinished, &packet);
  
                  // Did we get a video frame?
  
                  if(frameFinished)
  
                  {//and so on... But our problem is already here...

  Ok, now pFrame is holding a YUV representation of my frame... So, in order to check what I'm getting from the avcodec_decode_video2(...) function I'm just writing pFrame to a file so I can see it with any YUV reader on the web.

  char yuvFileName[100];
  
  sprintf(yuvFileName,"/storage/sdcard0/yuv%d.yuv",index);
  
  FILE* fp = fopen(yuvFileName, "wb");
  
  int y;
  
  // Write pixel data
  
  for(y=0; yheight; y++)
  
  {
  
      fwrite(pFrame->data[0]+y*pFrame->linesize[0], 1, gVideoCodecCtx->width, fp);    
  
  }
  
  for(y=0; yheight/2; y++)
  
  {
  
      fwrite(pFrame->data[1]+y*pFrame->linesize[1], 1, gVideoCodecCtx->width/2, fp);
  
  }
  
  for(y=0; yheight/2; y++)
  
  {
  
      fwrite(pFrame->data[2]+y*pFrame->linesize[2], 1, gVideoCodecCtx->width/2, fp);
  
  }
  
  fclose(fp);

  Ok so Here I now have my result on a file store @ /storage/sdcard0/blabla.YUV on my Galaxy Nexus root memory.

  But If I open the file with (for example XnView, which is meant to display YUV type properly) I only see Dark green on the picture.

  What bothers me is that everything worked properly on Galaxy S3 but something failed on GNexus...

  So here's my question : Why doesn't it work on Galaxy Nexus ?

  Compatibility problem between Gnexus and armeabiv7 ?

  I don't know !

  Regards,
  Cehm

• FFMPEG h.264 stream to VLC from raw YUV444 produces black screen

  30 novembre 2018, par GerbGerb

  Not sure if this fits better here or over on Super User, so please redirect if here is the wrong place.

  I am piping raw YUV444 640x480 frames to ffmpeg from inside a C++ program using stdout. ffmpeg encodes them using h.264 and streams the video via UDP to an IP of my choice.

  When I am not streaming and saving the video as -mp4 file, everything works - But when I stream over the network and try to receive in VLC, the stream is received and the playing timer under the video screen runs, but the image is black, none of the video is displayed. Also I have some crackling sounds on my audio output.

  My FFMPEG settings are as follows :

  ffmpeg -y -loglevel info -f rawvideo -r 25 -c:v rawvideo -pix_fmt yuv444p -s 640x480 -i - -c:v libx264 -preset superfast -framerate 25 -f mpegts udp://192.168.150.1:20001

  in VLC, I just use "open network stream" with udp ://@:20001. The port is open, I tested it with a simple dummy sender/receiver.
  Almost the same cli arguments for the video recording lead to a perfectly playable video when writing to a file and downloading it :

  ffmpeg -y -loglevel info -f rawvideo -r 25 -c:v rawvideo -pix_fmt yuv444p -s 640x480 -i - -c:v libx264 -preset superfast -framerate 25 video.mp4

  If I try to stream the same video using

  ffmpeg -i video.mp4 -v 0 -vcodec mpeg4 -f mpegts udp://192.168.150:20001

  the screen remains black.

  VLC debug output changes between different runs, because other modules are selected, so I assume stream type recognition goes haywire. But why ?

  What am I doing wrong ?

  Here the ffmpeg log
  and the VLC log