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• Revision 903801f1ef : vp9 decoder : row-based multi-threaded loopfilter Implemented parallel loopfilte

  28 décembre 2013, par Yunqing Wang

  Changed Paths :
   Modify /vp9/common/vp9_loopfilter.c

  
   Modify /vp9/common/vp9_loopfilter.h

  
   Modify /vp9/decoder/vp9_decodeframe.c

  
   Add /vp9/decoder/vp9_dthread.c

  
   Add /vp9/decoder/vp9_dthread.h

  
   Modify /vp9/decoder/vp9_onyxd_if.c

  
   Modify /vp9/decoder/vp9_onyxd_int.h

  
   Modify /vp9/decoder/vp9_thread.c

  
   Modify /vp9/decoder/vp9_thread.h

  
   Modify /vp9/vp9dx.mk

  
  
  vp9 decoder : row-based multi-threaded loopfilter

  Implemented parallel loopfiltering, which uses existing tile-
  decoding threads. Each thread works on one row, and when that row
  is loopfiltered, it moves to next unattended row. To ensure the
  correct filtering order, threads are synchronized and one
  superblock is filtered only if the superblocks it depends on are
  filtered already.

  To reduce synchronization overhead and speed up the decoder, we use
  nsync > 1 for high resolution.

  Performance tests :
  1. on desktop :
  8-tile 4k video using 8 threads, speedup : 70% - 80%
  4-tile HD video using 4 threads, speedup : 35%
  2. on mobile device(Nexus 7) :
  4-tile 1080p video using 4 threads, speedup : 18% - 25%
  4-tile 1080p video using 2 threads, speedup : 10% - 15%

  Change-Id : If54b4a11960dd706c22d5ad145ad94156031f36a

• Add new build based on jQuery UI build file

  20 mars 2011, par jzaefferer

  + build.xml + build/ant-contrib-0.6.jar + build/google-compiler-20110320.jar Add new build based on jQuery UI build file

• ffmpeg : Apply a time-based expr to control intensity of lowpass, highpass, aphaser, or aecho [closed]

  17 mai 2024, par Wes Modes

  I am procedurally constructing complexFilters for ffmpeg via fluent-ffmpeg. My fluent-ffmpeg complex filters look like :

  


  {
   "filter": "volume",
   "options": {
       "volume": "min(1, max(0, ((cos(PI * t * 1 / 13) * 1 + cos(PI * t * 1 / 7) * 0.5 + cos(PI * t * 1 / 3) * 0.25) +
-0.5 ) * 0.75 * -1 + 0.5))",
       "eval": "frame"
    },
    "inputs": "track_1_output",
    "outputs": "track_1_adjusted"
},


  


  Note that I am using an expression to determine the volume dynamically.

  


  Here I'm testing on the command line, to understand the mysteries of lightly-documented ffmpeg filters. I'm fading in and out two sources, intertwined in the output. Now I want to apply lowpass, highpass, aphaser, and/or aecho to the transitions using a time-based expr.

  


  I've already succeeded using the volume filter to fade the sources in and out (Note that the sine has reversed polarity for the second volume filter) :

  


  # working fade in/out
ffmpeg -i knox.mp3 -i static.mp3 -filter_complex \
"[0:a] \
    volume = 'min(1, max(0, 0.5 + 0.5 * cos(PI * t / 5)))': eval=frame \
    [a0]; \
[1:a] \
    volume = 'min(1, max(0, 0.5 - 0.5 * cos(PI * t / 5)))': eval=frame \
    [a1]; \
[a0][a1]
    amix = inputs=2: duration=shortest" \
-c:a libmp3lame -q:a 2 output.mp3


  


  ffmpeg -filters says that lowpass has time-based support :

  


    T.. = Timeline support
 TSC lowpass           A->A       Apply a low-pass filter with 3dB point frequency.


  


  How can I similarly apply these other filters to source1 using a time-bassed expr ? I was unsuccessful in figuring out lowpass and highpass :

  


  # applying a lowpass filter
ffmpeg -i knox.mp3 -i static.mp3 -filter_complex \
"[0:a] \
    volume = 'min(1, max(0, 0.5 + 0.5 * cos(PI * t / 5)))': eval=frame, \
    lowpass=f=3000: mix='0.5 + 0.5 * cos(PI * t / 5)' \
    [a0]; \
[1:a] \
    volume = 'min(1, max(0, 0.5 - 0.5 * cos(PI * t / 5)))': eval=frame \
    [a1]; \
[a0][a1]
    amix = inputs=2: duration=shortest" \
-c:a libmp3lame -q:a 2 output.mp3


  


  With the resultant error :

  


  [Parsed_lowpass_1 @ 0x7f9a72005c00] [Eval @ 0x7ff7bec423d8] Undefined constant or missing '(' in 't/5)'
[Parsed_lowpass_1 @ 0x7f9a72005c00] Unable to parse option value "0.5 + 0.5 * cos(PI * t / 5)"
Error applying option 'mix' to filter 'lowpass': Invalid argument


  


  What complicated fffmpeg faerie magic is needed to make some of the filters other than volume controlled by a time-based expr ?