#11657: libx265: -bufsize and -maxrate does not complement -x265-params vbv- init=0.9 -------------------------------------+------------------------------------- Reporter: Boopboop | Owner: (none) Type: defect | Status: new Priority: normal | Component: | undetermined Version: git-master | Resolution: Keywords: libx265 vbv | Blocked By: Blocking: | Reproduced by developer: 0 Analyzed by developer: 0 | -------------------------------------+------------------------------------- Description changed by Boopboop: Old description:
Summary of the bug: specifying the general {{{-bufsize}}} and {{{-maxrate}}} options, instead of using {{{-x265-params vbv-bufsize =:vbv-maxrate=}}}, forces vbv-init=0.75, instead of working together with a {{{-x265-params vbv-bufsize=0.9}}}, or leaving it out and letting it default to x265's default 0.9.
How to reproduce: {{{ % ffmpeg -report -loglevel 99 -to 1 -i DSC_0021.MOV -an -c:v libx265 -profile:v main10 -level:v 4.1 -bufsize 20M -maxrate 20M -preset:v veryslow -x265-params pools=6:frame-threads=1:vbv-init=0.9 DSC_0021.mp4 ffmpeg version N-120196-g6b028859d9 Copyright (c) 2000-2025 the FFmpeg developers built with Apple clang version 17.0.0 (clang-1700.0.13.5) configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/HEAD-6b02885_3 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host- cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable- libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable- librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable- libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable- libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable- libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable- libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon libavutil 60. 4.101 / 60. 4.101 libavcodec 62. 5.100 / 62. 5.100 libavformat 62. 1.101 / 62. 1.101 libavdevice 62. 0.100 / 62. 0.100 libavfilter 11. 1.100 / 11. 1.100 libswscale 9. 0.100 / 9. 0.100 libswresample 6. 0.100 / 6. 0.100
(snip) x265 [info]: HEVC encoder version 4.1+1-1d117be x265 [info]: build info [Mac OS X][clang 16.0.0][64 bit] 10bit x265 [info]: using cpu capabilities: NEON Neon_DotProd Neon_I8MM x265 [info]: Main 10 profile, Level-4 (High tier) x265 [info]: Thread pool created using 6 threads x265 [info]: Slices : 1 x265 [info]: frame threads / pool features : 1 / wpp(17 rows) x265 [info]: Coding QT: max CU size, min CU size : 64 / 8 x265 [info]: Residual QT: max TU size, max depth : 32 / 3 inter / 3 intra x265 [info]: ME / range / subpel / merge : star / 57 / 4 / 5 x265 [info]: Keyframe min / max / scenecut / bias : 25 / 250 / 40 / 5.00 x265 [info]: Lookahead / bframes / badapt : 40 / 8 / 2 x265 [info]: b-pyramid / weightp / weightb : 1 / 1 / 1 x265 [info]: References / ref-limit cu / depth : 5 / off / off x265 [info]: AQ: mode / str / qg-size / cu-tree : 2 / 1.0 / 32 / 1 x265 [info]: Rate Control / qCompress : CRF-28.0 / 0.60 x265 [info]: VBV/HRD buffer / max-rate / init : 20000 / 20000 / 0.750 <= Here, init 0.75 instead of 0.9 x265 [info]: tools: rect amp rd=6 psy-rd=2.00 rdoq=2 psy-rdoq=1.00 rskip mode=1 x265 [info]: tools: signhide tmvp b-intra strong-intra-smoothing deblock sao x265 [info]: tools: dhdr10-info }}}
New description: Summary of the bug: specifying the general {{{-bufsize}}} and {{{-maxrate}}} options, instead of using {{{-x265-params vbv-bufsize=:vbv- maxrate=}}}, forces vbv-init=0.75, instead of working together with a {{{-x265-params vbv-init=0.9}}}, or leaving it out and letting it default to x265's default 0.9. How to reproduce: {{{ % ffmpeg -report -loglevel 99 -to 1 -i DSC_0021.MOV -an -c:v libx265 -profile:v main10 -level:v 4.1 -bufsize 20M -maxrate 20M -preset:v veryslow -x265-params pools=6:frame-threads=1:vbv-init=0.9 DSC_0021.mp4 ffmpeg version N-120196-g6b028859d9 Copyright (c) 2000-2025 the FFmpeg developers built with Apple clang version 17.0.0 (clang-1700.0.13.5) configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/HEAD-6b02885_3 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host- cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable- libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable- libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable- libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable- libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable- libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon libavutil 60. 4.101 / 60. 4.101 libavcodec 62. 5.100 / 62. 5.100 libavformat 62. 1.101 / 62. 1.101 libavdevice 62. 0.100 / 62. 0.100 libavfilter 11. 1.100 / 11. 1.100 libswscale 9. 0.100 / 9. 0.100 libswresample 6. 0.100 / 6. 0.100 (snip) x265 [info]: HEVC encoder version 4.1+1-1d117be x265 [info]: build info [Mac OS X][clang 16.0.0][64 bit] 10bit x265 [info]: using cpu capabilities: NEON Neon_DotProd Neon_I8MM x265 [info]: Main 10 profile, Level-4 (High tier) x265 [info]: Thread pool created using 6 threads x265 [info]: Slices : 1 x265 [info]: frame threads / pool features : 1 / wpp(17 rows) x265 [info]: Coding QT: max CU size, min CU size : 64 / 8 x265 [info]: Residual QT: max TU size, max depth : 32 / 3 inter / 3 intra x265 [info]: ME / range / subpel / merge : star / 57 / 4 / 5 x265 [info]: Keyframe min / max / scenecut / bias : 25 / 250 / 40 / 5.00 x265 [info]: Lookahead / bframes / badapt : 40 / 8 / 2 x265 [info]: b-pyramid / weightp / weightb : 1 / 1 / 1 x265 [info]: References / ref-limit cu / depth : 5 / off / off x265 [info]: AQ: mode / str / qg-size / cu-tree : 2 / 1.0 / 32 / 1 x265 [info]: Rate Control / qCompress : CRF-28.0 / 0.60 x265 [info]: VBV/HRD buffer / max-rate / init : 20000 / 20000 / 0.750 <= Here, init 0.75 instead of 0.9 x265 [info]: tools: rect amp rd=6 psy-rd=2.00 rdoq=2 psy-rdoq=1.00 rskip mode=1 x265 [info]: tools: signhide tmvp b-intra strong-intra-smoothing deblock sao x265 [info]: tools: dhdr10-info }}} -- -- Ticket URL: <https://trac.ffmpeg.org/ticket/11657#comment:1> FFmpeg <https://ffmpeg.org> FFmpeg issue tracker