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Old 28th February 2019, 02:28   #44  |  Link
poisondeathray
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Join Date: Sep 2007
Posts: 5,340
Using Wolfberry's FFMpeg build with vpy support , direct vapoursynth input is about 50% speed compared to vspipe to the same ffmpeg . I would have expected marginally faster for direct vpy demuxer. Script is just QTGMC . I tried specifying different ffmpeg -threads values as an input argument. Any ideas, or am I doing something wrong? Could it be a cache issue ?

https://forum.doom9.org/showthread.p...31#post1866931

Code:
vspipe --y4m input.vpy - | "ffmpeg" -f yuv4mpegpipe -i - -an -f null NUL

Code:
"ffmpeg" -f vapoursynth -i input.vpy -an -f null NUL

EDIT #1: but another test of just reading a MP4 video with lsmash (no other filters, just source filter), direct vapoursynth is about 1.4-1.5x faster than vspipe to ffmpeg

EDIT #2: tested other source filters too lsmash, ffms2, other file types (mpeg2, avc); pretty consistent observation - direct read with only source filter is faster, but as soon as you add any additional filter in script (not just QTGMC, it can be anything like a denoiser, or even a simple resize only) it becomes slower than vspipe method at about 50% speed

Is it specific to this ffmpeg build, or do other people get different results with their own build ?

Last edited by poisondeathray; 28th February 2019 at 03:10.
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