Recherche avancée

Sur d’autres sites (7334)

• avformat/utils : Fix confusing return value for ff_read_packet()

  12 mars 2021, par Andreas Rheinhardt

  avformat/utils : Fix confusing return value for ff_read_packet()
  Currently, ff_read_packet() sometimes forwards the return value of
  
  AVInputFormat.read_packet() (which should be zero on success, but isn't
  
  for all demuxers) and sometimes it overwrites this with zero.
  
  Furthermore, it uses two variables, one for the read_packet return value
  
  and one for other errors, which is a bit confusing ; it is also
  
  unnecessary given that the documentation explicitly states that
  
  ff_read_packet() never returns positive values. Returning a positive
  
  value would lead to leaks with some callers (namely asfrtp_parse_packet
  
  and estimate_timings_from_pts). So always return zero in case of
  
  success.
  (This behaviour stems from a time before av_read_packet sanitized
  
  the return value of read_packet at all : It was added in commit
  
  626004690c23c981f67228ea325dde3f35193988 and was unnecessary since
  
  88b00723906f68b7563214c30333e48888dddf78.)
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavformat/utils.c

• avformat/tests/fifo_muxer : Fix memleak on error, fix API violation

  19 mars 2021, par Andreas Rheinhardt

  avformat/tests/fifo_muxer : Fix memleak on error, fix API violation
  The test program for the FIFO muxer allocates a buffer without padding
  
  and wraps it into a packet via av_packet_from_data(). This is an API
  
  violation. Furthermore, said buffer leaks in case av_packet_from_data()
  
  fails. Fix both of these issues by using av_new_packet() instead.
  Reviewed-by : James Almer <jamrial@gmail.com>
  
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavformat/tests/fifo_muxer.c

• How to properly abort av_seek_frame on FFmpeg ?

  5 mars 2021, par SuRGeoNix

  Normally, you wouldn't care aborting av_seek_frame as it would be really fast on a local file. However, in my case I use a custom AVIOContext for torrent streaming with custom read/seek functions and I'm not able to abort a single seek request !

  


  I've already tried interrupt callbacks (they will not be called at all), some timeouts (rw_timeout/timeout etc.) but by checking FFmpeg's code didn't find anything at all. My last chance was to try to return on read/seek functions an error (I've tried AVERROR_EXIT) which causes even more problems (memory leaks).

  


  The main issue is with Matroska formats that they need to resync (level-1) and they are trying to scan the whole file.

  


  Unfortunately, I'm using C# .NET with FFmpeg.Autogen bindings which means that I don't have low-level access to play around. My workaround is to re-open the whole format context in case on seek abort (to ensure that the player will continues to play at least)

  


  Hope you have a tip for me !

  


  (By the way for some http/hls web formats interrupt callbacks are supported)