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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>
  

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

• Expand (extend) a video to an specific duration [closed]

  1er octobre 2020, par BorrajaX

  Do VLC or FFmpeg (or AVconv) have any feature to force the duration of a video to a certain number of seconds ?

  



  Let's say I have a... 5 minutes .mp4 video (without audio). Is there a way to have any of the aforementioned tools "expanding" the video to a longer duration ? The video comes from a Power Point slideshow, but it's too short (running too fast, to say so). The idea would be automatically inserting frames so it reaches an specified duration. It looks like something pretty doable (erm... for a total newbie in video encoding/transcoding as I am) : A 5 minutes video, at 30fps means I have 9000 frames... To make it be 10 times longer, get the first "real" frame, copy it ten times, then get the second "real" frame, copy it ten times... and so on.

  



  I'm using Ubuntu 12.04, but I can install/compile any required software, if needed. So far, I have VLC, AVConv and FFmpeg (FFmpeg in an specific folder, so it won't conflict with AVConv)

  



  Thank you in advance.

  


• mmaldec : fix problems with flush logic

  8 septembre 2015, par wm4

  mmaldec : fix problems with flush logic
  Don’t try to do a blocking wait for MMAL output if we haven’t even sent
  
  a single real packet, but only flush packets. Obviously we can’t expect
  
  to get anything back.
  Additionally, don’t send a flush packet to MMAL in the same case. It
  
  appears the MMAL decoder will sometimes hang in mmal_vc_port_disable()
  
  (called from ffmmal_close_decoder()), waiting for a reply from the GPU
  
  which never arrives. Either MMAL disallows sending flush packets without
  
  preceding real data, or it’s a MMAL bug.
  Signed-off-by : Luca Barbato <lu_zero@gentoo.org>
  

  • [DBH] libavcodec/mmaldec.c