Recherche avancée

Sur d’autres sites (9767)

• FFMPEG : Transmux mpegts to mp4 gives error : muxer does not support non seekable output

  20 décembre 2019, par Kr0e

  When piping mpegts to ffmpeg, which should convert it to mp4 and pipe to stdout, ffmpeg says : "muxer does not support non seekable output".

  After a lot of research I came to the conclusion that mp4 is a bad choice for doing those kinds of on-the-fly transcoding due to seeking. So in essence : MP4 cannot be piped through ffmpeg, which kind of makes sense.

  But I do not have a contiguous mpegts stream, I have chunks of 5 seconds.
  So it’s really just like :

  • Here is my 1 mb *.ts file
  • Please read it from pipe until you hit EOF
  • Please transmux it to mp4 (if you really have to seek, well use a buffer)
  • Please pipe the complete internal mp4 buffer to stdout

  I need these mp4 chunks for a HTML5 MediaSource, the fragmentation is no problem, I use mp4box.js, which works like a charm.

  Questions :

  • Can FFMPEG do this kind of internal buffering ?
  • Is there any better option to consider ?

  In essence : Can I (somehow) interact with ffmpeg without using files ? My current solutions works with files and polling for new chunks, which is ugly.

  If you are interested in my ffmpeg command, just let me know.

• FFMPEG : Transmux mpegts to mp4 gives error : muxer does not support non seekable output

  7 décembre 2015, par Kr0e

  When piping mpegts to ffmpeg, which should convert it to mp4 and pipe to stdout, ffmpeg says : "muxer does not support non seekable output".

  After a lot of research I came to the conclusion that mp4 is a bad choice for doing those kinds of on-the-fly transcoding due to seeking. So in essence : MP4 cannot be piped through ffmpeg, which kind of makes sense.

  But I do not have a contiguous mpegts stream, I have chunks of 5 seconds.
  So it’s really just like :

  • Here is my 1 mb *.ts file
  • Please read it from pipe until you hit EOF
  • Please transmux it to mp4 (if you really have to seek, well use a buffer)
  • Please pipe the complete internal mp4 buffer to stdout

  I need these mp4 chunks for a HTML5 MediaSource, the fragmentation is no problem, I use mp4box.js, which works like a charm.

  Questions :

  • Can FFMPEG do this kind of internal buffering ?
  • Is there any better option to consider ?

  In essence : Can I (somehow) interact with ffmpeg without using files ? My current solutions works with files and polling for new chunks, which is ugly.

  If you are interested in my ffmpeg command, just let me know.

• The proper way to limit framerate when recording screen on macOS

  5 juillet 2024, par jsx

  macOS 14.5, FFmpeg 7.0.1. To record the screen, if I use the code from Wiki, that is,

  


  ffmpeg -f avfoundation -i 1 output.mp4


  


  the frame rate seems to be so high that when I press q to stop recording, the following message persists until my MacBook Pro starts to noise by its cooler : "[q] command received. Exiting."

  


  My current solution is to add -r after -i :

  


  ffmpeg -f avfoundation -i 1 -r 24 output.mp4


  


  But I heard that a more correct solution is to replace -r with -framerate and to put it before instead of after -i :

  


  


  ffmpeg -f avfoundation -framerate 24 -i 1 output.mp4


  


  Note that I used -framerate as an input option instead of -r 24 as an output option, so I'm telling avfoundation to record at 24fps instead of recording at the default fps and then forcing FFmpeg to drop or duplicate frames to give you the desired 24.

  


  


  This doesn't work for me currently, and appears to be the same as I don't use -r at all.

  


  And so, what is the proper way to fix the "too high framerate" issue when recording the screen on macOS ? Do we need -r or instead -framerate, and where to put it, before or after -i ?

  


  Just in case, here is the log of ffmpeg -f avfoundation -i 1 output.mp4 -v verbose :

  


  https://github.com/jsx97/test/blob/main/ffmpeg.log