[FFmpeg-trac] #4947(ffmpeg:new): libx264/265 encoder "parameter unknown" is a warning rather than an error

FFmpeg trac at avcodec.org
Tue Oct 20 00:42:52 CEST 2015

#4947: libx264/265 encoder "parameter unknown" is a warning rather than an error
             Reporter:  wader8       |                     Type:
               Status:  new          |  enhancement
            Component:  ffmpeg       |                 Priority:  wish
             Keywords:  warning,     |                  Version:  git-
  x264, x265, unknown, error,        |  master
  params                             |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
 Summary of the bug:
 A cyan-yellow warning is displayed when an invalid parameter is used for
 libx264/265 param options, which continues the encoding process,
 furthermore with the combined use of verbose messages the console output
 may scroll far enough for this error to be missed, it has created
 confusion that lead to assumption of a bug and has spent unnecessary
 effort and time spent in discussions.

 The mistake in this case was of the use of "-" minus/dash which is a
 ffmpeg param, not the encoder option.

 x265 case:
 Unknown option -crf.

 x264 case:
 Error parsing option "-crf = 20".

 As we can see, the x264 message is even closer, it is actually written as
 an error, but it still appears and behaves as a warning and the encoding
 process continues.

 How to reproduce:
 % ffmpeg -i input -x265-params -crf=20 ... output
 ffmpeg version ... N/A
 built on ... N/A

Ticket URL: <https://trac.ffmpeg.org/ticket/4947>
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