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• FFMPEG Video conversion

  29 avril 2023, par Saurabh Sharma

  Working on a project which requires conversion from video of quicktime to mp4 format
Using the javacv maven library

  


   <dependency>&#xA;        <groupid>org.bytedeco</groupid>&#xA;        <artifactid>javacv-platform</artifactid>&#xA;        <version>1.5.8</version>&#xA; </dependency>&#xA;&#xA;

  


  Here is the code format using MPEG4 codec

  


   public static ByteArrayOutputStream convertToMp4(String videoId, byte[] file) {
        classLogger.trace("request is received to convert video: " + videoId + " to mp4");
        FFmpegLogCallback.set();
        InputStream stream = new ByteArrayInputStream(file);
        Frame captured_frame = null;
        FFmpegFrameRecorder recorder = null;
        FFmpegFrameGrabber grabber = new FFmpegFrameGrabber(stream);
        SeekableByteArrayOutputStream outputStream = new SeekableByteArrayOutputStream();
        try {
            grabber.start();
            System.out.println("grabber frame rate " + grabber.getFrameRate()); //value is 29.85882710114861
            recorder = new FFmpegFrameRecorder(outputStream, grabber.getImageWidth(), grabber.getImageHeight(), grabber.getAudioChannels());
            recorder.setVideoCodec(avcodec.AV_CODEC_ID_MPEG4);
            System.out.println("recorder frame rate b4 " + recorder.getFrameRate()); //value is 30.0
            recorder.setFormat("mp4");
            recorder.setFrameRate(grabber.getFrameRate());
            recorder.setAudioMetadata(grabber.getAudioMetadata());
            recorder.setAudioOption("crf", "0");
            recorder.setAudioQuality(0);
            recorder.setVideoBitrate(grabber.getVideoBitrate());
            recorder.setAudioBitrate(grabber.getAudioBitrate());
            recorder.setSampleRate(grabber.getSampleRate());
            recorder.setVideoMetadata(grabber.getVideoMetadata());
            recorder.start();
            while ((captured_frame = grabber.grabFrame()) != null) {
                try {
                    recorder.setTimestamp(grabber.getTimestamp());
                    recorder.record(captured_frame);
                } catch (Exception e) {
                    classLogger.error(e.getMessage());
                }
            }
            recorder.stop();
            recorder.release();
            grabber.stop();
            grabber.release();
        } catch (Exception e) {
            e.printStackTrace();
        }
        return outputStream;
    }



  


  The following code fails with the error

  


  Error: [mpeg4 @ 0x7f61043a6e40] timebase 19763/590100 not supported by MPEG 4 standard, the maximum admitted value for the timebase denominator is 65535

org.bytedeco.javacv.FFmpegFrameRecorder$Exception: avcodec_open2() error -22: Could not open video codec. (For more details, make sure FFmpegLogCallback.set() has been called.)



  


  I tried changing frame rate to alter the value of timebase but was of no help

  


  I also tried changing the codec to H264 and here the video was converted successfully but there was a significant loss in frames and the video quality was distorted.
Even though the video was converted successfully there was the following error log during the conversion

  


  Error: [mp4 @ 0x7fc2486d9b80] Application provided invalid, non monotonically increasing dts to muxer in stream 0: 2094878 >= 2094878
av_interleaved_write_frame() error -22 while writing interleaved video packet. (For more details, make sure FFmpegLogCallback.set() has been called.)


  


  Any help will be highty appreciated, Thanks

  


• FFmpeg playback on iOS out of sync after conversion

  26 novembre 2013, par YYZ

  So I've got a mov file, and I'm converting it to .mp4 and then playing it back on both iOS and Android. There are no sync problems on Android, but iOS videos are always slightly out of sync.

  Here is my ffmpeg command :

  ffmpeg -i original.mov -threads 4 -c:a aac -cutoff 15000 -ab 96k -ar 22050 -c:v libx264 -s 638x360 -profile:v baseline -r 25 -movflags faststart -map_metadata:s:v -1:g -strict experimental -y out.mp4

  Is there anything obvious that stands out as wrong ?

• Video conversion with php ffmpeg not playable on browser

  7 octobre 2016, par Guille Terrasa

  I’m using the PHP FFMPEG Library https://github.com/PHP-FFMpeg/PHP-FFMpeg on a web application to convert some videos uploaded by the users in different formats to MP4 H264 video format, playable on most browsers.

  I have a problem with some MP4 videos with an specific codec, this videos are being converted succesfully with PHP FFMPEG but are not playable on the browser.

  • Type : Vídeo
  • Codec : H264 - MPEG-4 AVC (part 10) (H264)
  • Resolution : 320x258
  • Screen Resolution : 320x240
  • Framerate : 30.000300
  • Decoded Format : Planar 4:2:2 YUV full scale

  On other similar videos with a different version of the codec, the uploading and conversion process is working and the result is playable on the browser :

  • Type : Vídeo
  • Codec : H264 - MPEG-4 AVC (part 10) (avc1)
  • Resolution : 320x258
  • Screen Resolution : 320x240
  • Framerate : 30
  • Decoded Format : Planar 4:2:2 YUV

  The code used to convert the video server side with PHP FFMPEG is this :

  $video = $ffmpeg->open($path . '/' . $filename);
  
  $video->filters()
  
           ->resize(new \FFMpeg\Coordinate\Dimension($destWidth, $destHeight))
  
           ->synchronize();
  
  $video->save(new \FFMpeg\Format\Video\X264('libmp3lame'), $dest);

  And on the browser is loaded with a video tag :

  <video src="http://route/to/video.mp4" width="100%" height="auto" controls=""></video>

  Thanks