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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.

• poster adjustment after getting it from video

  30 juin 2016, par Jass

  I am capturing poster from this video https://www.youtube.com/watch?v=wg-kEWsL6Xc using following code. Video can be any, I am just giving example.

  shell_exec('ffmpeg -y  -itsoffset -4  -i "'.base_path().'/assets/videos/'.$file_name.'.mp4" -vcodec mjpeg -vframes 1 -an -f rawvideo -filter:v scale=1170:ih*1170/iw "'.base_path().'/assets/videos/thumbnail/'.$file_name.'.jpg"')

  Width = 1170px,

  Height= 300px (as it is background image so it does not matter)

  But I am facing adjustment problem. Following are my current views

  First : Head is cutting, here I am using css property background : url(’completepath’) center no-repeat ;
  

  Second : Showing black portion on top of head. This is the original image that I am getting from ffmpeg code.

  

  My Question : But I need image like in you tube, you can notice that in all videos we can see top portion of humans without being cutting even black portion is well adjusted.

  Currently I am downloading and testing with youtube videos but in actual job seekers will make their own videos using android/iphone or any camera and will upload on our site.

  so how i can overcome this issue means show image with proper human face and body ?

  thanks in advance.

• 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.)