[FFmpeg-trac] #4940(ffmpeg:new): Slower preset runs longer, but makes larger file

FFmpeg trac at avcodec.org
Sat Oct 17 00:13:06 CEST 2015

#4940: Slower preset runs longer, but makes larger file
             Reporter:  Larek   |                     Type:  defect
               Status:  new     |                 Priority:  normal
            Component:  ffmpeg  |                  Version:  unspecified
             Keywords:          |               Blocked By:
             Blocking:          |  Reproduced by developer:  0
Analyzed by developer:  0       |
 Summary of the bug:x264 preset failure
 How to reproduce:
 % ffmpeg -i input -preset slow -crf 18 -c:v libx264 output-S
 % ffmpeg -i input -preset slower -crf 18 -c:v libx264 output-Sr
 % ffmpeg -i input -preset veryslow -crf 18 -c:v libx264 output-Vs
 % ffmpeg -i input -preset placebo -crf 18 -c:v libx264 output
 ffmpeg version  N-75976-gd59bfcd
 Zeranoe Static Win32 build (linked from this site)
 built on 13-10-2015
 Slow    took 6min  produced 261MB file
 Slower  took 13min  produced 252MB file
 Veryslow took 24min  produced 230MB file
 Placebo took 83min produced 237MB file

 https://trac.ffmpeg.org/wiki/Encode/H.264 , says that
 A slower preset will provide better compression

 As time ''for me'' isn't a factor compared to quality and file size, I'll
 take that ~1% better {{{Placebo}}} should do over {{{Veryslow}}}. Heck if
 ffmpeg had a {{{Ludicrous}}} preset that took a similar job 24-48hours for
 a 4% gain I'd be using it.

 But just to see how much better {{{Placebo}}} has been doing, I ran a
 duplicate {{{Veryslow}}} job.  {{{Placebo}}} is producing a '''larger'''
 output from the same input file and settings than {{{Veryslow}}} job!

 More Detail
 Input #0, matroska,webm, from 'Disk02_(ep05-09)-001.mkv':
     encoder         : libebml v1.2.2 + libmatroska v1.3.0
     creation_time   : 2015-10-15 14:15:42
   Duration: 00:23:11.04, start: 0.000000, bitrate: 7332 kb/s
     Stream #0:0: Video: mpeg2video (Main), yuv420p(tv), 720x576 [SAR 16:15
 DAR 4:3], max. 9000 kb/s, 50 fps, 50 tbr, 1k tbn, 50 tbc (default)
     Stream #0:1: Audio: ac3, 48000 Hz, stereo, fltp, 192 kb/s (default)

 Stream mapping:
   Stream #0:0 -> #0:0 (mpeg2video (native) -> h264 (libx264))
   Stream #0:1 -> #0:1 (ac3 (native) -> vorbis (libvorbis))

Ticket URL: <https://trac.ffmpeg.org/ticket/4940>
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