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• 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 ?

  


• 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

• libx264 : Define X264_API_IMPORTS on MSVC/ICL

  19 juillet 2013, par Derek Buitenhuis

  libx264 : Define X264_API_IMPORTS on MSVC/ICL
  libx264 has a few data exports which require X264_API_IMPORTS
  
  to be defined if we link to libx264 dynamically on Windows.
  In a similar fashion to how we handle our compat snprintf
  
  implementation, if we define it all the time, the compiler
  
  will first try and link to __imp_x264_symbol_name, and failing
  
  that, as in the case of a static libx264, will attempt to link
  
  to the non-prefixed symbol, which has already been pulled in by
  
  other x264 functions’ object files.
  Signed-off-by : Derek Buitenhuis <derek.buitenhuis@gmail.com>
  

  • [DBH] libavcodec/libx264.c