[FFmpeg-trac] #5854(undetermined:new): H.264 encoding - veryfast preset produces smaller file than faster preset
FFmpeg
trac at avcodec.org
Mon Sep 19 23:05:23 EEST 2016
#5854: H.264 encoding - veryfast preset produces smaller file than faster preset
-------------------------------------+-------------------------------------
Reporter: mimac | Type: defect
Status: new | Priority: normal
Component: | Version:
undetermined | unspecified
Keywords: H.264 | Blocked By:
preset | Reproduced by developer: 0
Blocking: |
Analyzed by developer: 0 |
-------------------------------------+-------------------------------------
'''Summary of the bug:'''
According to [https://trac.ffmpeg.org/wiki/Encode/H.264], for constant
quality encoding, faster preset should be slower and produce smaller file
than veryfast preset. However, by my testing, faster preset produced
always bigger file than veryfast preset.
'''How to reproduce:'''
{{{
ffmpeg version N-81696-gd38dff8e-static http://johnvansickle.com/ffmpeg/
Copyright (c) 2000-2016 the FFmpeg developers
built with gcc 5.4.1 (Debian 5.4.1-2) 20160904
configuration: --enable-gpl --enable-version3 --enable-static --disable-
debug --enable-libmp3lame --enable-libx264 --enable-libx265 --enable-
libwebp --enable-libspeex --enable-libvorbis --enable-libvpx --enable-
libfreetype --enable-fontconfig --enable-libxvid --enable-libopencore-
amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvo-
amrwbenc --enable-gray --enable-libopenjpeg --enable-libopus --enable-
libass --enable-gnutls --enable-libvidstab --enable-libsoxr --enable-
frei0r --enable-libfribidi --disable-indev=sndio --disable-outdev=sndio
--enable-librtmp --enable-libmfx --enable-libzimg --cc=gcc-5
libavutil 55. 29.100 / 55. 29.100
libavcodec 57. 57.100 / 57. 57.100
libavformat 57. 49.100 / 57. 49.100
libavdevice 57. 0.102 / 57. 0.102
libavfilter 6. 62.100 / 6. 62.100
libswscale 4. 1.100 / 4. 1.100
libswresample 2. 1.100 / 2. 1.100
libpostproc 54. 0.100 / 54. 0.100
% ffmpeg -i newmobcal1920_12mbps.ts -c:v libx264 -profile:v high -level
4.0 -preset faster result-faster.mkv
% ffmpeg -i newmobcal1920_12mbps.ts -c:v libx264 -profile:v high -level
4.0 -preset veryfast result-veryfast.mkv
% ll *.mkv
-rw-rw-r-- 1 user user 84785654 Sep 19 21:28 result-faster.mkv
-rw-rw-r-- 1 user user 77822551 Sep 19 21:15 result-veryfast.mkv
}}}
Input video is from [http://www.w6rz.net]
([http://www.w6rz.net/newmobcal1920_12mbps.ts]). Reports are attached.
I was able to reproduce this behavior on Ubuntu as well as Windows, with
three different input files (H.264, MPEG2, MJPEG), also with CFR values
18, 23 and 28. Veryfast preset always produced smaller file than faster
and fast preset, in most cases also smaller than medium preset.
--
Ticket URL: <https://trac.ffmpeg.org/ticket/5854>
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