Recherche avancée

Sur d’autres sites (11473)

• Revision 0ca7855f67 : Use correct bit cost while static-thresh is on While static-thresh is on, we on

  31 août 2013, par Yunqing Wang

  Changed Paths :
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  Use correct bit cost while static-thresh is on

  While static-thresh is on, we only need to transmit skip
  flag if skip = 1. The cost of skip bit is added to the
  total rate cost.

  Change-Id : I64e73e482bc297eba22907026298a15fa8cc3920

• lavc/aacenc_utils : replace powf(x,y) by expf(logf(x), y)

  8 mars 2016, par Ganesh Ajjanagadde

  lavc/aacenc_utils : replace powf(x,y) by expf(logf(x), y)
  This is 2x faster for y not an integer on Haswell+GCC, and should
  
  generally be faster due to the fact that anyway powf essentially does
  
  this under the hood. Made an inline function in lavu/internal.h for this
  
  purpose.
  Note that there are some accuracy differences, that should generally be
  
  negligible. In particular, FATE still passes on this platform.
  Results in 7% speedup in aac encoding with -march=native, Haswell+GCC.
  
  before :
  
  ffmpeg -i sin.flac -acodec aac -y sin_new.aac  6.05s user 0.06s system 104% cpu 5.821 total
  after :
  
  ffmpeg -i sin.flac -acodec aac -y sin_new.aac  5.67s user 0.03s system 105% cpu 5.416 total
  This is also faster than an alternative approach that pulls in powf, gets rid of
  
  the crufty NaN checks and other special cases, exploits knowledge about the intervals, etc.
  
  This of course does not exclude smarter approaches ; just suggests that
  
  there would need to be significant work on this front of lower utility than
  
  searches for hotspots elsewhere.
  Reviewed-by : Reimar Döffinger <Reimar.Doeffinger@gmx.de>
  
  Reviewed-by : Ronald S. Bultje <rsbultje@gmail.com>
  
  Signed-off-by : Ganesh Ajjanagadde <gajjanag@gmail.com>
  

  • [DH] libavcodec/aacenc_utils.h
  • [DH] libavutil/internal.h

• ffmpeg - concatenate files while space constrained

  23 juillet 2023, par glodomorrapl

  Let's say i have a 2 TB drive. If i want to use ffmpeg to concatenate two files, they cannot be larger than 1 TB in total, otherwise I won't have enough storage space to save the output file.

  


  Is it possible for ffmpeg (or, perhaps, another tool) to losslessly concatenate two videos while also removing parts of the source files on the fly, allowing me to concatenate larger files ? The files in questions will be encoded with the ffv1 codec and saved as mkv, although I'm fine with trying different containers.

  


  Would saving files in smaller chunks to begin with be the only solution ?