Recherche avancée

Sur d’autres sites (6901)

• Is it possible to stream MJPEG content over MPEG-DASH ?

  26 juillet 2021, par Eloy Schultz

  I am trying to re-stream an MJPEG stream over dash using ffmpeg.

  


  I have an ESP32 camera module that outputs an MJPEG livestream at 192.168.2.128:81/stream (Arduino code here).
I can open this stream directly in the browser and see the video in realtime, but the camera will only allow for a single client at a time while I am in need of a multi client solution.

  


  What doesn't work

  
A solution I am currently trying to implement is to use a seperate server (Raspberry Pi) running apache and ffmpeg to re-stream the MJPEG content using DASH :


  ffmpeg -re -i http://192.168.2.128:81/stream -strict -2 -an -c:v copy -b:v 2000k -f dash -window_size 4 -extra_window_size 0 -min_seg_duration 2000000 -remove_at_exit 1 /var/www/html/out.mpd


  


  I get no errors when executing this command on the server.
I then use this ffmpeg-dash.html to display the video in the browser.
This code unfortunately fails, in Firefox the console reports the error :

  


  [72][Stream] No streams to play.


  


  followed by :

  


  Cannot play media. No decoders for requested formats: video/mp4;codecs="mp4v.6c";width="640";height="480"


  


  What does work

  
What is puzzling me is that the above code works fine if I replace the MJPEG livestream url with a sample .mkv file, so if I use


  ffmpeg -re -i /var/www/html/video.mkv -strict -2 -an -c:v copy -b:v 2000k -f dash -window_size 4 -extra_window_size 0 -min_seg_duration 2000000 -remove_at_exit 1 /var/www/html/out.mpd


  


  I can view the livestreamed sample video (video.mkv) without problems using the previously mentioned ffmpeg-dash.html file.
Furthermore, it seems that ffmpeg can read the MJPEG livestream without problems, since

  


  ffmpeg -t 10 -i http://192.168.2.128:81/stream -filter:v fps=15 -c:v flv test.flv


  


  returns a 10 second clip of the livestream succesfully.

  


  So to me it seems that the problem lies in how I combine the two. What am I missing ? Is it even possible to stream MJPEG content over MPEG-DASH ?
(I am new to this, sorry in advance for my ignorance)

  


• A/V out of sync when using ffmpeg from mpeg-ts to dash

  17 mai 2018, par user3540646

  I’m using ffmpeg in order to convert MPEG-TS stream to MPEG-DASH.
  The mpeg-ts is h264 and aac_latm.
  Therefore I don’t need to reencode the video.
  The command I use :

  ffmpeg -i http://10.0.0.211:55555/Ch%2011%20Kan -strict -2 -c:v copy -window_size 10 -extra_window_size 10 -use_template 1 -use_timeline 1 -f dash kan.mpd

  I’m copying the video codec by using -c:v copy and the audio codec is default to aac.

  That way I get DASH stream BUT the audio/video is out of sync !

  How can I fix it ?

  Notes :

  1. If I reencode both audio and video like :

     ffmpeg -i http://10.0.0.211:55555/Ch%2011%20Kan -strict -2 -window_size 10 -extra_window_size 10 -use_template 1 -use_timeline 1 -f dash kan.mpd

  Then the audio/video is synced perfectly.
  But I do not want to reencode the video for nothing as I mentioned the video is already h264. (directly impact to performance)

  2. If I convert the MPEG-TS stream to mp4 file like :

     ffmpeg -i http://10.0.0.211:55555/Ch%2011%20Kan -strict -2 -c:v copy kan.mp4

  Then the audio/video is synced perfectly.

• Reduce the number of chunk-stream files when converting to mpeg-dash

  10 juillet 2024, par NSS

  My command : ffmpeg -i input_file.mp4 -c:v libx264 -c:a aac -b:v 6000k -b:a 192k -f dash output.mpd

  


  When I convert a mpeg4 file into mpeg-dash, ffmpeg generates a certain number of .m4s files (e.g chunk-stream0-00003.m4s) of different sizes. If I convert a really large file ffmpeg can generate thousands of files like that. My questions are :

  


  

  1. how can I set that no .m4s file is more than 5MB ? I need this to stream a smaller chunk faster over HTTP.

  


  2. how can I reduce the number of generated .m4s files ? I need this because the custom storage has a limit on files in a directory.