[FFmpeg-trac] #7456(avcodec:new): aomdec decodes video faster than libaom-av1 decoder in ffmpeg

[FFmpeg]

#7456: aomdec decodes video faster than libaom-av1 decoder in ffmpeg
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             Reporter:  kagami      |                    Owner:  (none)
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  libaom      |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
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Comment (by veikk0):

 I just tested this with the latest git (3.1.2-702-g3adb660d for aom).
 libaom-av1 via FFmpeg seems to be about 20% slower than aomdec by itself.

 Also, -DCONFIG_LOWBITDEPTH=1 is no longer a valid build flag, and a
 message at the start of the build says to use
 -DFORCE_HIGHBITDEPTH_DECODING=0 instead. However, it's unclear whether
 this actually does anything, since performance seems identical with and
 without this option.

 My test on a system with 4 logical cores:

 {{{
 $ youtube-dl -f 399 -o av1.mp4 umyglbDr4IE
 $ ffmpeg -i av1.mp4 -c:v copy -frames:v 1800 av1.ivf
 $ /usr/bin/time -f "\ntime\t%E\nCPU\t%P\nRAM\t%Mk" ffmpeg -c:v libaom-av1
 -threads 4 -i av1.ivf -nostats -f null /dev/null
 $ /usr/bin/time -f "\ntime\t%E\nCPU\t%P\nRAM\t%Mk" aomdec -o /dev/null
 --threads=4 av1.ivf
 }}}

 dav1d is the default encoder nowadays in builds that include it, and
 therefore it's necessary to define libaom-av1 as the decoder.

 FFmpeg libaom-av1 performance:

 {{{
 ffmpeg

 time    0:33.81
 CPU     282%
 RAM     151252k
 }}}

 aomdec performance:

 {{{
 time    0:27.08
 CPU     283%
 RAM     68280k
 }}}

 The results stayed the same across multiple runs with very little
 variance.
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Ticket URL: <https://trac.ffmpeg.org/ticket/7456#comment:9>
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