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• Creating an MP4 video with ffmpeg from timestamped JPEG frames received by pipe

  16 août 2024, par Denis Fevralev

  I need to create a video with following conditions :

  


  

  1. It can only be made from a sequence of JPEG files, each having its timestamp (milliseconds) in the name. The images' durations are not the same, they differ, so i cannot just concat them all and use particular fps

  


  2. There are several tar archives with the images sequences, the archives are kind of huge so I read them from a file storage as an async steam of data and cannot save them on the disk as files. The frames are read and right away put to ffmpeg running process stdin.

  


  3. The images may have different aspect ratios so it's required to make a NxN square and scale the images to fit in with filling the empty space with pads

  


  


  My current solution :

  


  ffmpeg -r $someFpsValue -i - -vf scale=w=$w:h=$h:force_original_aspect_ratio=1,pad=$w:$h:(((ow-iw)/2)):(((oh-ih)/2)) result.mp4


  


  As you can see, it doesn't let me concat the images with correct durations. I know that the concat demuxer can solve the problem of merging images with different durations but seemingly it doesn't work with pipe protocol. I have an idea of evaluating an average fps as (videoFramesCount) / (videoDurationInSeconds) for -r argument, or maybe even counting the fps for each video's second and then getting the avg, but maybe there is a more reliable solution (like some concat demuxer analogue) ?

  


  Thanks in advance :)

  


• FFMPEG/MP4BOX Muxing .mp4 with .h262, .acc x2, and srt

  4 mai 2015, par can

  I’m going to attempt to re-ask this question.

  What I am wanting to do, is create one new mp4 file, which will include, one video file, two audio files and one subtitle file. I am wanting to create a mp4 file that I can playback on my iOS devices and computers.
  The files are as followed :

  • video.h264 23.976 fps
  • audioen.aac 44.1 KHz, 2, English
  • audiojp.aac 48.0 KHz, 5.1, Japanese
  • sub.srt

  Now this srt has been converted from a mks subtitle file from a Matroska file.
  I would like the English track to play by default, the Japanese track to be an option and the subtitle file to be another option.

  I am having a very hard time trying to work both, mp4box and ffmpeg to create this one file, can somebody please help me with the command.

• FFMPEG/MP4BOX Creating .mp4 with .h262, .acc x2, and srt

  2 mai 2015, par can

  I’m going to attempt to re-ask this question.

  What I am wanting to do, is create one new mp4 file, which will include, one video file, two audio files and one subtitle file. I am wanting to create a mp4 file that I can playback on my iOS devices and computers.
  The files are as followed :

  • video.h264 23.976 fps
  • audioen.aac 44.1 KHz, 2, English
  • audiojp.aac 48.0 KHz, 5.1, Japanese
  • sub.srt

  Now this srt has been converted from a mks subtitle file from a Matroska file.
  I would like the English track to play by default, the Japanese track to be an option and the subtitle file to be another option.

  I am having a very hard time trying to work both, mp4box and ffmpeg to create this one file, can somebody please help me with the command.