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• how to uses ffmpeg's xfade transition filter to connect multiple video files to a single file by cshrp ?

  8 septembre 2021, par Mark2

  how to uses FFmpeg's xfade transition filter to connect multiple video files to a single file by cshrp ?

  


  I find a scripts on GitHub :https://github.com/qq2225936589/xfade-ffmpeg-script , but I did not good at shell scripts.
I read the official documents and spliced the two videos. If there are more than one, my idea is to splice two by two, and then splice them into a large one. Is there a better solusion ?

  


• fftools/ffmpeg_demux : Don't use fake object with av_opt_eval

  6 octobre 2023, par Andreas Rheinhardt

  fftools/ffmpeg_demux : Don't use fake object with av_opt_eval
  The av_opt_eval family of functions emits errors messages on error
  
  and can therefore not be used with fake objects when the AVClass
  
  has a custom item_name callback. The AVClass for AVCodecContext
  
  has such a custom callback (it searches whether an AVCodec is set
  
  to use its name). In practice it means that whatever is directly
  
  after the "cc" pointer to the AVClass for AVCodec in the stack frame
  
  of ist_add() will be treated as a pointer to an AVCodec with
  
  unpredictable consequences.
  Fix this by using an actual AVCodecContext instead of a fake object.
  Reviewed-by : Anton Khirnov <anton@khirnov.net>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] fftools/ffmpeg_demux.c

• Glitchy mp4 File saved with Matplotlib Animation via ffmpeg

  9 janvier 2024, par Jacob Ivanov

  I am attempting to save an .mp4 file using matplotlib.animation to output some simulation results. The relevent section is as follows :

  


  ANI = FuncAnimation(fig, update, init_func = lambda : None, frames = range(0, 21300, 50))
ANI.save("[removed]/anim/v6 256 unforced 0.02.mp4", dpi = 600, fps = 30, writer = 'ffmpeg')


  


  However, it appears that there is some issue in the produced .mp4 file, as when I use macOS Quicktime to view the file, it pauses on certain frames, and restarts later on. It appears to consistently pause on the same frame a few seconds in. In order to check if Quicktime was the problem, I opened some random .mp4 files I found in a family group chat, and did not have this issue.

  


  I also tried viewing this .mp4 file with VLC, which had no issue, and played without any glitches. The Slack media viewer built into the app pauses similar to Quicktime.

  


  The following are all relevant versions :

  


  

  • macOS : 14.2.1 (23C71)

  


  • Python : 3.10.9 via Homebrew

  


  • Matplotlib : 3.6.2

  


  • ffmpeg : 6.1.1

  


  


  If it would help, I can also provide the .mp4 file itself, but I'm not quite sure how to upload it. I will be happy to provide any additional information as well.

  


  Unfortunately, I'm not very familiar with video rendering, but I would appreciate any help anyone could provide. Thank you in advance !