Am Do., 24. Sept. 2020 um 17:13 Uhr schrieb Emmanuel Dreyfus <m...@netbsd.org>: > > 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
While FFmpeg is not responsible for vp8 encoding performance, I would still strongly recommend that you recompile or download a saner binary: Yours is so massively broken that the decoding speed is probably very slow. I should add that a default configuration (without any options) leads to nearly the highest possible speed. (Disclaimer: vp8 encoding is typically slow but if libvpx is compiled like FFmpeg above the speed can certainly be improved) Carl Eugen _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
