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• Revision df90d58f4f : Speed up motion estimation using small partitions' result(experiment) Current p

  3 juillet 2013, par Yunqing Wang

  Changed Paths :
   Modify /vp9/encoder/vp9_block.h

  
   Modify /vp9/encoder/vp9_encodeframe.c

  
   Modify /vp9/encoder/vp9_onyx_if.c

  
   Modify /vp9/encoder/vp9_onyx_int.h

  
   Modify /vp9/encoder/vp9_rdopt.c

  
  
  Speed up motion estimation using small partitions' result(experiment)

  Current partition checking starts from small sizes, and then goes up
  to large sizes. This experiment uses the small partitions' motion
  estimation result, which is already available, to speed up the
  large partition's motion estimation. We can decide to skip some
  patition checkings if they are unlikely choices. We could use the
  motion vector(MV) result as current partition's prediction MV, limit
  the search range and reference frame.

  Current result at speed 1 :
  psnr loss : 1.19% for stdhd, 0.287% for derf.
  speed gain : 14% for sunflower(hd), 11% for akiyo.

  Further improvement will be done later.

  Change-Id : I5abfd070e9cace2e91e2a0247d1325df313887ab

• Revision faff6ed0fb : Skip duplicate block encoding in the rd loop This speed feature allows the enco

  9 juillet 2013, par Jingning Han

  Changed Paths :
   Modify /vp9/encoder/vp9_block.h

  
   Modify /vp9/encoder/vp9_encodeframe.c

  
   Modify /vp9/encoder/vp9_encodeintra.c

  
   Modify /vp9/encoder/vp9_encodemb.c

  
   Modify /vp9/encoder/vp9_onyx_if.c

  
   Modify /vp9/encoder/vp9_onyx_int.h

  
   Modify /vp9/encoder/vp9_rdopt.c

  
   Modify /vp9/encoder/vp9_rdopt.h

  
  
  Skip duplicate block encoding in the rd loop

  This speed feature allows the encoder to largely remove the spatial
  dependency between blocks inside a 64x64 superblock, thereby removing
  the need to repeatedly encode superblocks per partition type in the
  rate-distortion optimization loop.

  A major challenge lies in the intra modes tested in the rate-distortion
  optimization loop. The subsequent blocks do not have access to the
  reconstructed boundary pixels without the intermediate coding steps.
  This was resolved by using the original pixels for intra prediction
  in the rd loop, followed by an appropriately designed distortion
  modeling on the quantization parameters. Experiments also suggested
  that the performance impact is more discernible at lower bit-rate/psnr
  settings. Hence a quantizer dependent threshold is applied to deactivate
  skip of block coding.

  For bus_cif at 2000 kbps,
  speed 0 : runtime 269854ms -> 237774ms (12% speed-up) at 0.05dB
  performance loss.

  speed 1 : runtime 65312ms -> 61536ms, (7% speed-up) at 0.04dB
  performance loss.

  This operation is currently turned on in settings of speed 1.

  Change-Id : Ib689741dfff8dd38365d8c1b92860a3e176f56ec

• ffmpeg speed up video - Windows

  11 avril 2016, par Flash Thunder

  In manual it says :

  ffmpeg -i input.mkv -filter:v 'setpts=0.5*PTS' output.mkv

  But when I run :

  ffmpeg -i input.mp4 -filter:v 'setpts=0.5*PTS' speedup.mp4

  I get an error :

  [AVFilterGraph @ 0000000002500600] No such filter: 'setpts=0.5*PTS'
  
  Error opening filters!

  Not sure if it means that filter can’t be opened at all or simply this filter is not available.

  How do I run it correctly ? Or maybe my release does not support it, then where can I get the release that would work right ? Win32/x64 binary