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• ffmpeg glue 4 videos on split screen with preview

  18 janvier 2023, par rst630

  I have 4 video files 480x1080 with audio - all different duration.

  


  I need 1920x1080 video

  


  _____________________________________________
|          |          |          |          |
|          |   first  |  first   |  first   |
|   play   |   frame  |  frame   |  frame   |
|          |          |          |          |
---------------------------------------------

_____________________________________________
|          |          |          |          |
|          |   play   |  first   |  first   |
|   last|  |          |  frame   |  frame   |
|   frame  |          |          |          |
---------------------------------------------


  


  when first video done 2nd column video must start and first video must show just last frame, other left 2 videos still show first frame and wait queue

  


  for example lets say we have these durations :

  


  1.mp4 - 1:00
2.mp4 - 1:35
3.mp4 - 1:20
4.mp4 - 1:05


  


  Also I can prepare screenshots of each video for preview frames (first/last)

  


  Cant even imagine how to do this job with ffmpeg or maybe exists any simplier way for shell ?

  


  example of output video https://www.youtube.com/watch?v=vdBd5-8uOTo

  


• ffmpeg : prevent premature EOF in sub2video with nullptr AVSubtitles

  31 mars 2018, par Jan Ekström

  ffmpeg : prevent premature EOF in sub2video with nullptr AVSubtitles
  With certain types of input and the filter chain getting re-initialized
  
  or re-configured, multiple nullptr AVSubtitles can get pushed into
  
  sub2video_update() in a row from sub2video_heartbeat.
  This causes end_pts, and on the next round pts, to become INT64_MAX,
  
  latter of which signals EOF in framesync, leading to complete loss of
  
  subtitles from that point on.
  Thus, check that the sub2video.end_pts is smaller than INT64_MAX
  
  in a similar fashion to sub2video_flush before sending out the
  
  nullptr AVSubtitle. This keeps premature EOFs from happening in
  
  framesync and the subtitle overlay is kept past the filter chain
  
  re-initializations/configurations.
  

  • [DH] fftools/ffmpeg.c

• How to open a HEIF (.heic) image ?

  14 décembre 2022, par Jean-Milost Reymond

  For a c++ project, I need to open and show a HEIF (.heic) image. What I know (if I'm right) is that the HEIF images are based on the ffmpeg standard, and requires a H265 codec to be read.

  



  I found several open-source H265 codecs :

  



  

  • OpenHEVC (https://github.com/OpenHEVC/openHEVC)

  


  • x265 (https://bitbucket.org/multicoreware/x265/downloads/)

  


  • libde265 (https://github.com/strukturag/libde265)

  


  



  I can open and show H265 encoded video files with each of them, but I'm unable to simply open, show or convert a .heic image. All of them return an error, or just do nothing.

  



  To be honest I'm a little puzzled, because the HEIF standard seem to be a well kept secret. I'm unable to find a relevant info that could allow me to walk to a solution. Those I found are just tricks and workarounds, like e.g. forcing the device (I'm speaking here about the Apple iPhone using the new iOS11) to generate a jpg image instead of a heic, or using a third party application like dr.fone. Of course these solutions are irrelevant for me.

  



  So, somebody can tell me which codec I should use with a .heif image, and how I can use it to open it ? Or are there open source libraries or examples that allow to manipulate this type of image file ? Somebody can point me to the good direction ?