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• lavu : fix memory leaks by using a mutex instead of atomics

  14 novembre 2014, par wm4

  lavu : fix memory leaks by using a mutex instead of atomics
  The buffer pool has to atomically add and remove entries from the linked
  
  list of available buffers. This was done by removing the entire list
  
  with a CAS operation, working on it, and then setting it back again
  
  (using a retry-loop in case another thread was doing the same thing).
  This could effectively cause memory leaks : while a thread was working on
  
  the buffer list, other threads would allocate new buffers, increasing
  
  the pool’s total size. There was no real leak, but since these extra
  
  buffers were not needed, but not free’d either (except when the buffer
  
  pool was destroyed), this had the same effects as a real leak. For some
  
  reason, growth was exponential, and could easily kill the process due
  
  to OOM in real-world uses.
  Fix this by using a mutex to protect the list operations. The fancy
  
  way atomics remove the whole list to work on it is not needed anymore,
  
  which also avoids the situation which was causing the leak.
  Signed-off-by : Anton Khirnov <anton@khirnov.net>
  

  • [DBH] libavutil/buffer.c
  • [DBH] libavutil/buffer_internal.h

• Burn picture in picture from two streams with ffmpeg

  9 juillet 2021, par Nagy Alfred

  I have a nice opportunity solving this with ffmpeg, but can not find solution :

  


  I need to burn picture in picture (pip from Desktop capture) to the top right corner of a recorded rtsp stream.

  


  I need to do it real time with the recording command (it can be really easy after the recording, but I do not have time to do it after the recording)

  


  The recording is done with this command :

  


  


  


  ffmpeg -i "rtsp://[username]:[pass]@xx.xx.xx.xx/cam/realmonitor?channel=1&subtype=0&unicast=true" -map 0:v -c:v copy -an -fflags flush_packets -max_delay 3 -flags -global_header -hls_time 20 -hls_list_size 1000 -vcodec copy -y "video.m3u8"

  


  


  



  The picture in picture is a Desktop capture with ffmpeg (real time capturing, not an existing video).

  


  Please help me solving this problem.

  


  Thanks !

  


• avfilter/showcqt : remove yuv offset

  3 novembre 2015, par Muhammad Faiz

  avfilter/showcqt : remove yuv offset
  this makes draw_bar faster
  
  slightly different result with old version
  check result (with 3 minutes audio file) :
  
  old :
  
      real    0m49.611s
  
      user    0m49.260s
  
      sys     0m0.073s
  
  new :
  
      real    0m47.606s
  
      user    0m47.378s
  
      sys     0m0.068s
  
  PSNR between old and new :
  
  yuv444p PSNR
  
      y:109.519298 u:107.506485 v:104.746878
  
      average:106.816074 min:99.167305 max:inf
  
  yuv422p PSNR
  
      y:109.519298 u:108.025801 v:104.489734
  
      average:107.279817 min:98.007467 max:inf
  
  yuv420p PSNR
  
      y:109.519298 u:108.363875 v:105.290200
  
      average:108.261511 min:97.461812 max:inf
  Signed-off-by : Michael Niedermayer <michael@niedermayer.cc>
  

  • [DH] libavfilter/avf_showcqt.c