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• Process Multiple Streams using ffmpeg-python

  27 novembre 2019, par C Dorman

  I have a MPEG-2 TS with a stream of video and a steam of KLV metadata. I can use ffmpeg-python to process each of these streams independently. For example, I can get the video stream, process each frames using numpy as shown in the docs. I can also get the data stream and show it in following way (using the library klvdata) :

  process = (
  
      ffmpeg
  
          .input(in_filename)
  
          .output('pipe:', format='data', codec='copy', map='data-re')
  
          .run_async(pipe_stdout=True, pipe_stderr=True)
  
  )
  
  
  
  for packet in klvdata.StreamParser(process.stdout.read()):
  
      packet.structure()
  
  
  
  process.wait()

  How do I do these at the same time ? I need to split the TS data into its streams and process them both, keeping them in sync. ffmpeg by itself can demultiplex the streams into separate files, but how do I handle the streams in python. The KLV has information that I want to show on top of the video stream (recognition boxes).

• lavf/movenc : Use a dynamic buffer when writing the mfra box

  23 juin 2020, par Derek Buitenhuis

  lavf/movenc : Use a dynamic buffer when writing the mfra box
  When doing streamed output, with e.g. +dash, if the mfra box ended
  
  up being larger than the AVIOContext write buffer, the (unchecked)
  
  seeking back to update the box size would silently fail and produce
  
  an invalid mfra box.
  This is similar to how other boxes are written in fragmented mode.
  Signed-off-by : Derek Buitenhuis <derek.buitenhuis@gmail.com>
  

  • [DH] libavformat/movenc.c

• MSE video fragments [closed]

  21 juin 2024, par Bogdan Rusu

  I am trying to build a Javascript web streammer, which uses MediSource and a buffer.
I append to the buffer every new fragment that is comming, which allows me to stream a video.

  


  To be more in context, its done with MPEG DASH. I have the video init.mp4 file and the m4s fragments.

  


  However, I want to add some videos that are pure mp4 video, and I cannot append them to the buffer, since they are not fragments related to the first stream. I was thinking about converting them to m4s fragment, but I don't understand how to do it. As far as I've read, m4s fragments are mp4 videos without the initial metadata and some other atoms/boxes removed.

  


  Is there a way to convert a mp4 video to one big m4s segment of the same duration and to properly append it to the MediaSource buffer ? Is there a way to manually create a m4s segment from a mp4 video ?

  


  I tried multiple tools such as Bento4 and some ffmpeg commands that converts the mp4 video in a mp4 fragment. But every time I append it to the buffer, the video stops and cannot read further. Especially with chrome.

  


  With bento4, after I mp4fragment, chrome can't seem to play the second fragment and the player always stops.