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• ffmpeg : md5 of m3u8 playlists generated from same input video with different segment durations (after applying video filter) don't match

  15 juillet 2020, par Saurabh P Bhandari

  Here are a few commands I am using to convert and transize a video in mp4 format to a m3u8 playlist.

  


  For a given input video (mp4 format), generate multiple video only segments with segment duration 30s

  


  ffmpeg -loglevel error -i input.mp4 -dn -sn -an -c:v copy -bsf:v h264_mp4toannexb -copyts -start_at_zero -f segment -segment_time 30 30%03d.mp4 -dn -sn -vn -c:a copy audio.aac


  


  Apply video filter (in this case scaling) on each segment and convert it to a m3u8 format

  


  ls 30*.mp4 | parallel 'ffmpeg -loglevel error -i {} -vf scale=-2:144 -hls_list_size 0 {}.m3u8'


  


  Store the list of m3u8 files generated in list.txt in this format file 'segment-name.m3u8'

  


  for f in 30*.m3u8; do echo "file '$f'" >> list.txt; done


  


  Using concat demuxer, combine all segment files (which are in m3u8 format) and the audio to get one final m3u8 playlist pointing to segments with duration of 10s.

  


  ffmpeg -loglevel error -f concat -i list.txt -i audio.aac -c copy -hls_list_size 0 -hls_time 10 output_30.m3u8


  


  ---

  


  I can change the segment duration in the first step from 30s to 60s, and compare the md5 of the final m3u8 playlist generated in both the cases using this command

  


  ffmpeg -loglevel error -i <input m3u8="m3u8" playlist="playlist" /> -f md5 - &#xA;

  


  The md5 of the output files differ i.e video streams of output_30.m3u8 and output_60.m3u8 are not the same.

  


  Can anyone elaborate on this ?

  


  (I expected the md5 to be the same)

  


• Streaming through FFMpeg stdout

  30 juin 2014, par SandyEmerald

  I need to stream my generating images using ffmpeg througth stdout. Is it possible ? If yes, could you give me some ffmpeg examples like commands or general conceptions ?

  The final task is to create streaming video server through RTP, so i could connect to it via VLC or other client. And i need to do it without using diskspace - only through streams.

  Now i have Qt program which generates images. I know that i can give them to stdout using QDataStream.

• How to convert mp4 to mp3 in Android Java ?

  16 août 2023, par Akshit

  I have the mp4 link of a video but don't have a link for the mp3 version of that mp4 video. So is there any way that I can convert that mp4 video to mp3 in Android ? I saw some resources but nothing works for me. I have two ways in which I believe this can be achieved

  


  

  1. Convert the mp4 link to mp3 directly. (Not Sure if this is achievable)

  


  2. Download the mp4 on the device with the help of a link and then use some code to convert that mp4 to mp3.

  


  


  I also tried some solutions which are available online

  


  https://github.com/tanersener/mobile-ffmpeg

  


  I tried the above library to achieve the final goal. But got : Async command execution failed with returnCode=1.

  


  This error in the code I am using is :

  


  private class Mp4ToMp3ConverterTask extends AsyncTask {
    @Override
    protected String doInBackground(String... params) {
        String mp4FilePath = params[0];
        String mp3OutputPath = Environment.getExternalStorageDirectory().getAbsolutePath() + "/output.mp3";

        String[] ffmpegCommand = {"-i", mp4FilePath, "-vn", "-ar", "44100", "-ac", "2", "-b:a", "192k", mp3OutputPath};


        Config.enableStatisticsCallback(new StatisticsCallback() {
            public void apply(Statistics newStatistics) {
                Log.d("Dekh", String.format("frame: %d, time: %d", newStatistics.getVideoFrameNumber(), newStatistics.getTime()));
            }
        });

        long executionIdd = FFmpeg.executeAsync(ffmpegCommand, new ExecuteCallback() {
            @Override
            public void apply(final long executionId, final int returnCode) {
                if (returnCode == RETURN_CODE_SUCCESS) {
                    Log.i("Dekh", "Async command execution completed successfully.");
                } else if (returnCode == RETURN_CODE_CANCEL) {
                    Log.i("Dekh", "Async command execution cancelled by user.");
                } else {
                    Log.i("Dekh", String.format("Async command execution failed with returnCode=%d.", returnCode));
                }
            }
        });

        FFmpeg.cancel(executionIdd);

        return mp3OutputPath;
    }
}


  


  Solution number 2 which I used is :

  


  https://androidprogrammatically425516919.wordpress.com/2020/04/21/how-to-convert-video-to-audio-in-android-programmatically/

  


  But I got an error here also : Failed to instantiate extractor.
  
And another error is : java.io.FileNotFoundException: open failed: EISDIR (Is a directory)

  


  I tried the online available solution to solve these errors but nothing worked. Such as granting write permission. Providing a valid location to save the output.

  


  But nothing works so far. Please help me on this. Thank you.