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• lpc : remove "decay" argument

  18 juin 2013, par Loren Merritt

  lpc : remove "decay" argument
  We never used the rolling-average mode, and this makes av_update_lls 15% faster.
  Signed-off-by : Luca Barbato <lu_zero@gentoo.org>
  

  • [DBH] libavcodec/lpc.c
  • [DBH] libavutil/lls.c
  • [DBH] libavutil/lls.h

• Revision c24d922396 : Add averaging-SAD functions for 8-point comp-inter motion search. Makes first 5

  25 juin 2013, par Ronald S. Bultje

  Changed Paths :
   Modify /vp9/common/vp9_rtcd_defs.sh

  
   Modify /vp9/encoder/vp9_mcomp.c

  
   Modify /vp9/encoder/vp9_onyx_if.c

  
   Modify /vp9/encoder/vp9_sad_c.c

  
   Modify /vp9/encoder/vp9_variance.h

  
   Modify /vp9/encoder/x86/vp9_sad_sse2.asm

  
  
  Add averaging-SAD functions for 8-point comp-inter motion search.

  Makes first 50 frames of bus @ 1500kbps encode from 3min22.7 to 3min18.2,
  i.e. 2.3% faster. In addition, use the sub_pixel_avg functions to calc
  the variance of the averaging predictor. This is slightly suboptimal
  because the function is subpixel-position-aware, but it will (at least
  for the SSE2 version) not actually use a bilinear filter for a full-pixel
  position, thus leading to approximately the same performance compared to
  if we implemented an actual average-aware full-pixel variance function.
  That gains another 0.3 seconds (i.e. encode time goes to 3min17.4), thus
  leading to a total gain of 2.7%.

  Change-Id : I3f059d2b04243921868cfed2568d4fa65d7b5acd

• Generating 64kbps audio-only mpegts for HTTP Live segmenter to meet 64kbps audio only requirement

  14 juin 2013, par Pobre

  I am trying to convert our mp4 files into mpeg-ts and segment it into .ts files for my iphone app to play. I am using Carson McDonalds's HTTP-Live-Video-Stream-Segmenter-and-Distributor to do that.

  I got his stuff complied and working correctly. I am currently trying to meet Apple's requirement where I need to provide a baseline 64 kbps audio only stream to my m3u8 playlist.
  Carson doesn't seem to have a profile for that.

  I need to be able to generate 64kbps audio-only stream from mp4, and turn that into mpeg-ts for the segmenter into ts. I am trying to find the right ffmpeg command that will validate without problem using Apple's mediastreamvalidator.

  So far I modified an existing encoding profile to try to achieve 64kbps total :

  ffmpeg -er 4 -i %s -f mpegts -acodec libmp3lame -ar 22050 -ab 32k -s 240x180 -vcodec libx264 -b 16k -flags +loop+mv4 -cmp 256 -partitions +parti4x4+partp8x8+partb8x8 -subq 7 -trellis 1 -refs 5 -coder 0 -me_range 16 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -bt 64k -maxrate 16k -bufsize 16k -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -level 30 -aspect 4:3 -r 10 -g 30 -async 2 - | %s %s %s %s %s

  but then when I try to validate it using mediastreamvalidator, it gives error after few ts :

  Playlist Validation : OK

  Segments :

  sample_cell_4x3_64k-00001.ts :

  WARNING : Media segment exceeds target duration of 10.00 seconds by 1.30 seconds (segment duration is 11.30 seconds)

  sample_cell_4x3_64k-00002.ts :

  WARNING : Media segment exceeds target duration of 10.00 seconds by 1.40 seconds (segment duration is 11.40 seconds)

  ....
  ....

  sample_cell_4x3_64k-00006.ts :

  ERROR : (-1) Unknown video codec : 1836069494 (program 0, track 0)
  ERROR : (-1) failed to parse segment as either an MPEG-2 TS or an ES

  sample_cell_4x3_64k-00007.ts :

  ERROR : (-1) Unknown video codec : 1836069494 (program 0, track 0)
  ERROR : (-1) failed to parse segment as either an MPEG-2 TS or an ES

  ....
  ....
  Average segment duration : 10.26 seconds
  Average segment bitrate : 376797.92 bps
  Average segment structural overhead : 349242.17 bps (92.69 %)

  Is there someway I can generate this correctly with just audio which totals 64kbps and turn it into mpeg-ts ready to be segmented and validated correctly ?

  Am I approaching the problem right ?