[FFmpeg-user] VP8 encoding performances

[Emmanuel Dreyfus]

Hello

I am looking for ways to improve VP8 encoding performance. I work with 5
mn long, 5 MB large MPEG4 test video. Here is the codec information from
ffprobe

  Duration: 00:05:08.20, start: 0.000000, bitrate: 150 kb/s
    Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 32000 Hz,
mono, fltp, 53 kb/s (default)
(...)
    Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
2256x1080, 94 kb/s, 25 fps, 25 tbr, 30k tbn, 60k tbc (default)

The goal is to produce a webm/VP8 video for clients that cannot consume
H264. I run this:
ffmpeg -i test.mp4 -vf scale=-2:720 -movflags +faststart -preset
ultrafast -f webm -c:v libvpx -b:v 1M -acodec libvorbis -y test.webm

It works, although being extremely slow: it runs for an hour to encode 5
mn of video. What improvement can be done here?

I tried rebuilding with configure --arch that fits the CPU, it does not
seems to help a lot. 

I wonder if GPU acceleration could help. I see there is some
documentation about it on the Wiki, but there ie no buying advice. I
have a 16 lane PCIe slot available, what card should I try to use here?

Or perhaps the ffmpeg command line above has some room for improvement?

Any other idea?

Here are ffmpeg build informations:
ffmpeg version 4.3 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 7.4.0 (nb3 20190319)
  configuration: --enable-avfilter --enable-avresample --enable-postproc
--enable-rpath --disable-ffplay --enable-fontconfig --enable-libfreetype
--enable-libass --enable-libaom --disable-htmlpages --enable-gnutls
--disable-mbedtls --disable-libopencore-amrnb
--disable-libopencore-amrwb --disable-openssl --disable-libjack
--disable-libpulse --disable-libtesseract --enable-libtheora
--enable-libvorbis --enable-libmp3lame --enable-libopus
--enable-libspeex --enable-libxvid --enable-libx264 --enable-libx265
--enable-vdpau --enable-vaapi --enable-libvpx --enable-libwebp
--enable-libxcb --enable-libxcb-shape --enable-libxcb-shm
--enable-libxcb-xfixes --enable-libbluray --disable-asm --arch=i386
--cc=gcc --disable-debug --disable-optimizations --disable-stripping
--enable-gpl --enable-libxml2 --enable-pthreads --enable-shared
--mandir=/usr/pkg/man --prefix=/usr/pkg --progs-suffix=4
--datadir=/usr/pkg/share/ffmpeg4 --docdir=/usr/pkg/share/doc/ffmpeg4
--incdir=/usr/pkg/include/ffmpeg4 --libdir=/usr/pkg/lib/ffmpeg4
--shlibdir=/usr/pkg/lib/ffmpeg4 --enable-runtime-cpudetect
  libavutil      56. 51.100 / 56. 51.100
  libavcodec     58. 91.100 / 58. 91.100
  libavformat    58. 45.100 / 58. 45.100
  libavdevice    58. 10.100 / 58. 10.100
  libavfilter     7. 85.100 /  7. 85.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  7.100 /  5.  7.100
  libswresample   3.  7.100 /  3.  7.100
  libpostproc    55.  7.100 / 55.  7.100
Hyper fast Audio and Video encoder


-- 
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu at netbsd.org