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• Error to encode audio though out the video in FFmpegFrameRecorder

  28 mars 2016, par Ragghwendra Suryawanshi

  Hello Stack World,

  I am trying to crate video from images in android using FFMpeg and
  javacv. I am able to crate video from images with out audio, when i try
  the same thing with audio video is crated but audio is just for 1
  sec of the video

          FFmpegFrameRecorder myFFmpegFrameRecorder = new FFmpegFrameRecorder(new StringBuilder(String.valueOf(strPath)).append("/").append(this.FileName).toString(), 640, 480, frameGrabber.getAudioChannels());
  
          myFFmpegFrameRecorder.setVideoCodec(13);
  
          myFFmpegFrameRecorder.setFormat("mp4");
  
          myFFmpegFrameRecorder.setPixelFormat(0);
  
          myFFmpegFrameRecorder.setSampleFormat(frameGrabber.getSampleFormat());
  
          myFFmpegFrameRecorder.setSampleRate(44100);
  
          myFFmpegFrameRecorder.setFrameRate(1.0d);
  
          myFFmpegFrameRecorder.setVideoBitrate(AccessibilityEventCompat.TYPE_TOUCH_INTERACTION_START);
  
          myFFmpegFrameRecorder.setAudioCodec(avcodec.AV_CODEC_ID_MP3);
  
          boolean isAudioFinish = false;
  
          try {
  
              frameGrabber.start();
  
              IplImage iplimage = new IplImage();
  
              myFFmpegFrameRecorder.start();
  
              for (int i = 0; i <= imgname - 1; i++) {
  
                  for (int j = 0; j <= 6; j++) {
  
                      Frame frame = frameGrabber.grabFrame();
  
                      if (frame != null) {
  
                          myFFmpegFrameRecorder.record(frame);
  
                      }
  
                      long l1 = 1000L * (System.currentTimeMillis() - l);
  
                      if (l1 < myFFmpegFrameRecorder.getTimestamp()) {
  
                          l1 = 1000L + myFFmpegFrameRecorder.getTimestamp();
  
                      }
  
                      myFFmpegFrameRecorder.setTimestamp(l1);
  
                  }
  
  
  
                  iplimage = opencv_highgui.cvLoadImage(myObjects.get(i).toString());
  
                  myFFmpegFrameRecorder.record(iplimage);
  
                  opencv_core.cvReleaseImage(iplimage);
  
              }
  
              myFFmpegFrameRecorder.stop();
  
              frameGrabber.stop();
  
          } catch (Exception e) {
  
              e.printStackTrace();
  
          }

  Please help me to solve it. I am missing something due to which it not working out here. I have read doc of the FFmpegFrameRecorder but unable to find my error.

• Parsing avconv/ffmpeg rawvideo output ?

  23 avril 2013, par DigitalMan

  I'm about to begin a project that will involve working with the output of avconv/ffmpeg, pixel-by-pixel, in rgb32 format. I intend to work with a raw byte stream, such as from the pipe protocol. Basic pointer arithmetic (C/C++) will be used to iterate over these pixels, and modify them in arbitrary manners in real-time.

  I've created a very small file using rawvideo format and codec, and opened it up in a hex editor. As expected, it's just a series of pixels, read right to left, top to bottom. No distinguishing between lines - no problem, if you know how wide the video is beforehand. No distinguishing between frames - no problem, if you also know how tall the video is. No file header for frame rate, or even what the encoding (rgb32, rgb24, yuv, etc.) is - again, as long as you already know, it can be worked with.

  The problem occurs when - for one reason or another - some bytes are missing. Maybe the stream isn't being examined from the beginning, which is likely be the case in my project, or maybe something just got lost. All the pre-existing knowledge in the world (besides maybe a byte count of what's been missed, not gonna happen) won't prevent it from happily chugging along, with an incorrect offset of line and frame.

  So, what I'm looking for is an option for rawvideo, or possibly some other format/codec, that will allow me to work with the resulting stream at the pixel level, in RGB, yet still have a clear definition of where a new frame begins, even if it happens to start "looking" in the middle of a frame. (Width, height, and framerate will indeed be known.)

• Encoded images into H264 video are skipped and/or missing ?

  25 juillet 2013, par Jona

  I'm trying to encode images into an H264 MP4 video. The issues I'm having is that some of the images are skipped or at the end of the video simply missing. I need the video to play every single image I encode since it is an animation.

  Any help setting the encoder properly would be greatly appreciated !

  Encoder settings :

  AVCodecContext *c;
  
  ...
  
  c->codec_id = AV_CODEC_ID_H264;
  
  c->bit_rate = mOutputWidth*mOutputHeight*4;//400000;
  
  /* Resolution must be a multiple of two. */
  
  c->width    = mOutputWidth;
  
  c->height   = mOutputHeight;
  
      /* timebase: This is the fundamental unit of time (in seconds) in terms
  
       * of which frame timestamps are represented. For fixed-fps content,
  
       * timebase should be 1/framerate and timestamp increments should be
  
       * identical to 1. */
  
  c->time_base.den = mFps;
  
  c->time_base.num = 1;
  
  c->gop_size      = 12; /* emit one intra frame every twelve frames at most */
  
  c->pix_fmt       = AV_PIX_FMT_YUV420P;
  
  ...
  
  av_dict_set(&pOptions, "preset", "medium", 0);
  
  av_dict_set(&pOptions, "tune", "animation", 0);
  
  
  
  /* open the codec */
  
  ret = avcodec_open2(c, codec, &pOptions);
  
  if (ret < 0) {
  
      LOGE("Could not open video codec: %s", av_err2str(ret));
  
      return -1;
  
  }

  Update 07/24/13 :
  I was able to achieve a better video by setting the gop_size=FPS and writing the last video frame repeatedly FPS+1 times seemed to resolve all issues. To me it seems odd to do that but might be something standard in the video encoding world ? Any tips feedback about this ?