[FFmpeg-trac] #6890(ffmpeg:new): Misleading log message for -b:a option

[FFmpeg]

#6890: Misleading log message for -b:a option
--------------------------------+--------------------------------------
             Reporter:  tmatth  |                     Type:  defect
               Status:  new     |                 Priority:  normal
            Component:  ffmpeg  |                  Version:  git-master
             Keywords:          |               Blocked By:
             Blocking:          |  Reproduced by developer:  0
Analyzed by developer:  0       |
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 Summary of the bug:

 When using the -b:a option, ffmpeg logs report "Applying option b:a (video
 bitrate (please use -b:v)) with argument 160k."
 It seems like this option is not actually interpreted as the video
 bitrate, but the message is misleading.
 Using the deprecated -ab option yields an expected message, "Applying
 option ab (audio bitrate (please use -b:a)) with argument 160k."



 How to reproduce:
 {{{
 % ffmpeg -y -loglevel trace -f lavfi -t 1 -i anullsrc -c:a libopus -b:a
 160k -c copy -f nut /dev/null

 ffmpeg version N-89369-g5a93a85fd0 Copyright (c) 2000-2017 the FFmpeg
 developers
   built with gcc 7 (Debian 7.2.0-16)
   configuration: --enable-gpl --enable-libopus -=enable-debug=gdb
   libavutil      56.  4.100 / 56.  4.100
   libavcodec     58.  6.102 / 58.  6.102
   libavformat    58.  2.103 / 58.  2.103
   libavdevice    58.  0.100 / 58.  0.100
   libavfilter     7.  6.100 /  7.  6.100
   libswscale      5.  0.101 /  5.  0.101
   libswresample   3.  0.101 /  3.  0.101
   libpostproc    55.  0.100 / 55.  0.100
 Splitting the commandline.
 Reading option '-y' ... matched as option 'y' (overwrite output files)
 with argument '1'.
 Reading option '-loglevel' ... matched as option 'loglevel' (set logging
 level) with argument 'trace'.
 Reading option '-f' ... matched as option 'f' (force format) with argument
 'lavfi'.
 Reading option '-t' ... matched as option 't' (record or transcode
 "duration" seconds of audio/video) with argument '1'.
 Reading option '-i' ... matched as input url with argument 'anullsrc'.
 Reading option '-c:a' ... matched as option 'c' (codec name) with argument
 'libopus'.
 Reading option '-b:a' ... matched as option 'b' (video bitrate (please use
 -b:v)) with argument '160k'.
 Reading option '-c' ... matched as option 'c' (codec name) with argument
 'copy'.
 Reading option '-f' ... matched as option 'f' (force format) with argument
 'nut'.
 Reading option '/dev/null' ... matched as output url.
 Finished splitting the commandline.
 Parsing a group of options: global .
 Applying option y (overwrite output files) with argument 1.
 Applying option loglevel (set logging level) with argument trace.
 Successfully parsed a group of options.
 Parsing a group of options: input url anullsrc.
 Applying option f (force format) with argument lavfi.
 Applying option t (record or transcode "duration" seconds of audio/video)
 with argument 1.
 Successfully parsed a group of options.
 Opening an input file: anullsrc.
 detected 8 logical cores
 [AVFilterGraph @ 0x55b9e6bc7ee0] query_formats: 2 queried, 3 merged, 0
 already done, 0 delayed
 [Parsed_anullsrc_0 @ 0x55b9e6bc9260] sample_rate:44100
 channel_layout:'stereo' nb_samples:1024
 [lavfi @ 0x55b9e6bc71c0] All info found
 [lavfi @ 0x55b9e6bc71c0] stream 0: start_time: 0.000 duration:
 -209146758205323.719
 [lavfi @ 0x55b9e6bc71c0] format: start_time: 0.000 duration:
 -9223372036854.775 bitrate=705 kb/s
 Input #0, lavfi, from 'anullsrc':
   Duration: N/A, start: 0.000000, bitrate: 705 kb/s
     Stream #0:0, 1, 1/44100: Audio: pcm_u8, 44100 Hz, stereo, u8, 705 kb/s
 Successfully opened the file.
 Parsing a group of options: output url /dev/null.
 Applying option c:a (codec name) with argument libopus.
 Applying option b:a (video bitrate (please use -b:v)) with argument 160k.
 Applying option c (codec name) with argument copy.
 Applying option f (force format) with argument nut.
 Successfully parsed a group of options.
 Opening an output file: /dev/null.
 [file @ 0x55cd85c1a680] Setting default whitelist 'file,crypto'
 Successfully opened the file.
 Output #0, nut, to '/dev/null':
   Metadata:
     encoder         : Lavf58.2.103
     Stream #0:0, 0, 1/44100: Audio: pcm_u8 (PUD[8] / 0x8445550), 44100 Hz,
 stereo, u8, 705 kb/s
 Stream mapping:
   Stream #0:0 -> #0:0 (copy)
 Press [q] to stop, [?] for help
 cur_dts is invalid (this is harmless if it occurs once at the start per
 stream)
 No more output streams to write to, finishing.
 size=      88kB time=00:00:00.99 bitrate= 725.9kbits/s speed=1.46e+03x
 video:0kB audio:88kB subtitle:0kB other streams:0kB global headers:0kB
 muxing overhead: 0.543768%
 Input file #0 (anullsrc):
   Input stream #0:0 (audio): 45 packets read (92160 bytes);
   Total: 45 packets (92160 bytes) demuxed
 Output file #0 (/dev/null):
   Output stream #0:0 (audio): 44 packets muxed (90112 bytes);
   Total: 44 packets (90112 bytes) muxed
 0 frames successfully decoded, 0 decoding errors
 [AVIOContext @ 0x55cd85c1a800] Statistics: 0 seeks, 2 writeouts

 }}}

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Ticket URL: <https://trac.ffmpeg.org/ticket/6890>
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