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• Video encoding libraries for Windows

  8 février 2012, par John

  ffmpeg is a widely used cross-platform library. But it doesn't support Visual C++, meaning you have to jump through hoops.

  And considering they say the following, it's clear they don't give $0.02 about MSVC users and that makes me uncomfortable for a serious project.. how can one of the most widely used cross-platform libraries not support the most common toolset on the most common OS ?

  There have been efforts to make FFmpeg compatible with MSVC++ in the
  past. However, they have all been rejected as too intrusive,
  especially since MinGW does the job adequately. None of the core
  developers work with MSVC++ and thus this item is low priority. Should
  you find the silver bullet that solves this problem, feel free to
  shoot it at us.

  We strongly recommend you to move over from MSVC++ to MinGW tools.

  It seems unlikely all the Windows developers are doing all this messing about, so are there more Windows-friendly libraries around ?

• How does one go about undoing an avformat_seek_file call in libavcodec ?

  2 juillet 2020, par John Allard

  I have an application written around libavcodec that sometimes attempts to seek ahead in a video while performing some work. The call to avformat_seek_file can only seek to a keyframe, so sometimes I end up in a situation where it ends up seek backwards from my current position in the decoding routine causing me to have to repeat work. For example, if I'm on frame 150 and I want to seek to frame 200, but the only key frames in the file are on frames 1 and 100, this call will have me seek back to frame 100, meaning I now have to decode 100 frames to get to 200 instead o 50 frames to get to 200 from my original decoding position of frame 150.

  


  Is there a way for me to tell avformat_seek_file to undo its last seek and reset me to my previous location ? Is there some other way for me to "save" my decoding state to undo this wrongful seek manually ?

  


  edit - it should be noted that my videos are always h264 encoded in an mp4 container.

  


• Comparison of two ffmpeg commands for video segment

  14 juillet 2021, par Anas Ansari

  I have two commands for making video segments in android ffmpeg

  


  

  • -ss startTime -i inputVideo -f segment -segment_time segmentDuration -reset_timestamps 1 -vcodec copy -b:v2 097152 -b:a 48000 -ac 2 -ar 22050 outputPath

  


  • -ss startTime -i inputVideo -f segment -segment_time segmentDuration -reset_timestamps 1 outputPath

  


  


  I have tried them both and noticed that first command is very very fast than second

  


  Since I am new to ffmpeg , i really don't know them meaning of every argument in these commands

  


  Can anyone plz explain me why first command is better and will it cause any errors in future