[FFmpeg-trac] #1080(FFmpeg:new): Pixel format autoselection does not work correctly with -vf format

[FFmpeg]

#1080: Pixel format autoselection does not work correctly with -vf format
---------------------------------------+--------------------------------
               Reporter:  cehoyos      |                  Owner:
                   Type:  enhancement  |                 Status:  new
               Priority:  minor        |              Component:  FFmpeg
                Version:  git-master   |               Keywords:
             Blocked By:               |               Blocking:
Reproduced by developer:  0            |  Analyzed by developer:  0
---------------------------------------+--------------------------------
 (bug 252 by Alex Converse)
 If the format video filter is used, ffmpeg's pixel format auto selection
 does not work as expected:
 {{{
 $ ./ffmpeg -i tests/lena.pnm -pix_fmt yuv422p -vcodec mpeg2video -qscale 2
 out.mpg
 }}}
 {{{
 $ ./ffmpeg -i out.mpg -vf format=yuv420p -vcodec mpeg2video out2.mpg
 ffmpeg version N-38811-ga04a97b Copyright (c) 2000-2012 the FFmpeg
 developers
   built on Mar 15 2012 14:40:16 with gcc 4.3.2
   configuration: --cc=/usr/local/gcc-4.3.2/bin/gcc --enable-gpl
   libavutil      51. 42.100 / 51. 42.100
   libavcodec     54. 10.100 / 54. 10.100
   libavformat    54.  2.100 / 54.  2.100
   libavdevice    53.  4.100 / 53.  4.100
   libavfilter     2. 64.101 /  2. 64.101
   libswscale      2.  1.100 /  2.  1.100
   libswresample   0.  7.100 /  0.  7.100
   libpostproc    52.  0.100 / 52.  0.100
 [mpeg @ 0x8eb8aa0] Format mpeg detected only with low score of 25,
 misdetection possible!
 Input #0, mpeg, from 'out.mpg':
   Duration: N/A, start: 0.500000, bitrate: N/A
     Stream #0:0[0x1e0]: Video: mpeg2video (4:2:2), yuv422p, 256x256 [SAR
 1:1 DAR 1:1], 104857 kb/s, 25 tbr, 90k tbn, 50 tbc
 [buffer @ 0x8ed1720] w:256 h:256 pixfmt:yuv422p tb:1/1000000 sar:1/1
 sws_param:
 [buffersink @ 0x8ec02c0] auto-inserting filter 'auto-inserted scale 0'
 between the filter 'Parsed_format_0' and the filter 'out'
 [format @ 0x8ec0720] auto-inserting filter 'auto-inserted scale 1' between
 the filter 'src' and the filter 'Parsed_format_0'
 [scale @ 0x8eb3060] w:256 h:256 fmt:yuv422p -> w:256 h:256 fmt:yuv420p
 flags:0x4
 [scale @ 0x8ec0560] w:256 h:256 fmt:yuv420p -> w:256 h:256 fmt:yuv422p
 flags:0x4
 [mpeg @ 0x8ebf300] VBV buffer size not set, muxing may fail
 Output #0, mpeg, to 'out2.mpg':
   Metadata:
     encoder         : Lavf54.2.100
     Stream #0:0: Video: mpeg2video, yuv422p, 256x256 [SAR 1:1 DAR 1:1],
 q=2-31, 200 kb/s, 90k tbn, 25 tbc
 Stream mapping:
   Stream #0:0 -> #0:0 (mpeg2video -> mpeg2video)
 Press [q] to stop, [?] for help
 frame=    1 fps=0.0 q=3.8 Lsize=      12kB time=00:00:00.04
 bitrate=2457.6kbits/s
 video:11kB audio:0kB global headers:0kB muxing overhead 8.092892%
 }}}
 ffmpeg chooses yuv422p for out2.mpg although yuv420p was requested on the
 command line.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/1080>
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