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• lavu : Add av_gettime_relative

  22 octobre 2014, par Martin Storsjö

  lavu : Add av_gettime_relative
  Since av_gettime() is used in a number of places where actual
  
  real time clock is required, the monotonic clock introduced in
  
  ebef9f5a5 would have consequences that are hard to handle. Instead
  
  split it into a separate function that can be used in the cases
  
  where only relative time is desired.
  On platform where no monotonic clock is available, the difference
  
  between the two av_gettime functions is not clear, and one could
  
  mistakenly use the relative clock where an absolute one is
  
  required. Therefore add an offset, to make it evident that the
  
  time returned from av_gettime_relative never is actual current
  
  real time, even though it is based on av_gettime.
  Based on a patch by Olivier Langlois.
  Signed-off-by : Martin Storsjö <martin@martin.st>
  

  • [DH] doc/APIchanges
  • [DH] libavutil/time.c
  • [DH] libavutil/time.h
  • [DH] libavutil/version.h

• avformat/hlsenc : Don't segfault on uncommon names

  6 mai 2020, par Andreas Rheinhardt

  avformat/hlsenc : Don't segfault on uncommon names
  The parsing process of the AVOpt-enabled string controlling the mapping
  
  of input streams to variant streams is roughly as follows : Space and tab
  
  separate variant stream group maps while the entries in each variant
  
  stream group map are separated by ','.
  The parsing process of each variant stream group proceeded as follows :
  
  At first the number of occurences of "a :", "v :" and "s :" in each variant
  
  stream group is calculated so that one can can allocate an array of
  
  streams with this number of entries. Then the string is split along ','
  
  and each substring is parsed. If such a substring starts with "a :", "s :"
  
  or "v :" it is treated as stream specifier and (if there is a correct
  
  number after ' :') a stream of the variant stream is mapped to one of the
  
  actual input streams.
  Nothing actually guarantees that the number of streams allocated initially
  
  equals the number of streams that are mapped to an actual input stream.
  
  These numbers can differ if e.g. the name, the sgroup, agroup or ccgroup
  
  of the variant stream contain "a :", "s :" or "v :".
  The problem hereby is that the rest of the code presumes these numbers
  
  to be equal and segfaults if it isn't (because the corresponding input
  
  stream is NULL).
  This commit fixes this by modifying the initial counting process to only
  
  count occurences of "a :", "s :" or "v :" that are at the beginning or that
  
  immediately follow a ','.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@gmail.com>
  

  • [DH] libavformat/hlsenc.c

• ffmpeg - where to save the video I plan to cut to frames

  28 décembre 2017, par Kyle

  I have ffmpeg up and running on my computer.

  Now I am trying to cut a video into individual frames. The video is titled IMG_2299.MOV.

  I am using the following command :

  ffmpeg -i img_2299.mov $filename%12d.jpeg

  Two questions :
  1) where do I need the actual video saved for this to work ? In the same folder as the ff* executable files (/usr/loca/bin) ?
  2) And where will the images created be saved ?

  I can run the command above — but I don’t see any results.

  Thank you for any help you can offer.