Recherche avancée

Sur d’autres sites (10068)

• libx264 2 pass encoding with mbtree option, first pass fails

  25 août 2012, par lightdee

  I'm working on an application which uses libx264. When doing 2-pass encodes, if the mbtree option is enabled, the 1st pass doesn't seem to
  put anything into the stats files :

      x264_1345845358591.L.mbtree.temp (size of 0)
  
      x264_1345845358591.L.temp
  
  
  
      $ cat x264_1345845358591.L.temp 
  
      #options: 288x162 fps=2997/100 timebase=100/2997 bitdepth=8 cabac=0 ref=3 
  
      deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 
  
      mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 
  
      fast_pskip=1 chroma_qp_offset=-2 threads=48 sliced_threads=0 nr=0 
  
      decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 
  
      weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 
  
      rc=abr mbtree=1 bitrate=210 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 
  
      ip_ratio=1.40 aq=1:1.00**

  When I do x264_encoder_open() for the 2nd pass, I get the failure message :

      x264 [error]: ratecontrol_init: can't open stats file
  
      x264 [error]: x264_encoder_open failed

  So it seems to be failing in the first pass. 2pass works fine if I turn off mbtree. I can run it with presets or tune parameters as long as mbtree is turned off. What parameter (see above list) might make mbtree fail in the first pass ?

• libx264 2 pass encoding with mbtree option, first pass fails

  25 août 2012, par lightdee

  I'm working on an application which uses libx264. When doing 2-pass encodes, if the mbtree option is enabled, the 1st pass doesn't seem to
  put anything into the stats files :

      x264_1345845358591.L.mbtree.temp (size of 0)
  
      x264_1345845358591.L.temp
  
  
  
      $ cat x264_1345845358591.L.temp 
  
      #options: 288x162 fps=2997/100 timebase=100/2997 bitdepth=8 cabac=0 ref=3 
  
      deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 
  
      mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 
  
      fast_pskip=1 chroma_qp_offset=-2 threads=48 sliced_threads=0 nr=0 
  
      decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 
  
      weightp=0 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 
  
      rc=abr mbtree=1 bitrate=210 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 
  
      ip_ratio=1.40 aq=1:1.00**

  When I do x264_encoder_open() for the 2nd pass, I get the failure message :

      x264 [error]: ratecontrol_init: can't open stats file
  
      x264 [error]: x264_encoder_open failed

  So it seems to be failing in the first pass. 2pass works fine if I turn off mbtree. I can run it with presets or tune parameters as long as mbtree is turned off. What parameter (see above list) might make mbtree fail in the first pass ?

• WebVTT Audio Descriptions for Elephants Dream

  10 mars 2015, par silvia

  When I set out to improve accessibility on the Web and we started developing WebSRT – later to be renamed to WebVTT – I needed an example video to demonstrate captions / subtitles, audio descriptions, transcripts, navigation markers and sign language.

  I needed a freely available video with spoken text that either already had such data available or that I could create it for. Naturally I chose “Elephants Dream” by the Orange Open Movie Project , because it was created under the Creative Commons Attribution 2.5 license.

  As it turned out, the Blender Foundation had already created a collection of SRT files that would represent the English original as well as the translated languages. I was able to reuse them by merely adding a WEBVTT header.

  Then there was a need for a textual audio description. I read up on the plot online and finally wrote up a time-alignd audio description. I’m hereby making that file available under the Create Commons Attribution 4.0 license. I’ve added a few lines to the medadata headers so it doesn’t confuse players. Feel free to reuse at will – I know there are others out there that have a similar need to demonstrate accessibility features.