[FFmpeg-trac] #3008(avfilter:open): ffmpeg converts video to grayscale if yadif filter used

[FFmpeg]

#3008: ffmpeg converts video to grayscale if yadif filter used
------------------------------------+------------------------------------
             Reporter:  tborisow    |                    Owner:
                 Type:  defect      |                   Status:  open
             Priority:  important   |                Component:  avfilter
              Version:  git-master  |               Resolution:
             Keywords:  regression  |               Blocked By:
             Blocking:              |  Reproduced by developer:  1
Analyzed by developer:  0           |
------------------------------------+------------------------------------
Changes (by cehoyos):

 * status:  new => open
 * reproduced:  0 => 1
 * component:  FFmpeg => avfilter
 * priority:  normal => important
 * version:  2.0.1 => git-master
 * keywords:  yadif grayscale ffmpeg => regression


Comment:

 For future tickets: Please always test current git head and please always
 add the complete, uncut console output.

 Several work-arounds exist:
 {{{
 $ ffmpeg -i out format=yuv420p,yadif,scale=200x200 -ar 22050 0.flv
 }}}

 I originally thought that this is a duplicate of ticket #2559 but since
 this is a regression since 6adf97f, I don't think so.

 The scale filter has to be inserted twice because yadif does not support
 the input pixel format and you generally cannot resize before
 deinterlacing. For the specific case (input pal8, yadif, resize, output
 yuv420p), the problem can be fixed imo because the trivial choice works,
 for other encoders, it would be more difficult to see the right pix_fmt.
 {{{
 $ ffmpeg -loglevel verbose -i fate-suite/cram/skating.avi -vf
 yadif,scale=200x200 out.flv
 ffmpeg version N-56717-gface578 Copyright (c) 2000-2013 the FFmpeg
 developers
   built on Sep 29 2013 08:41:46 with gcc 4.7 (SUSE Linux)
   configuration: --enable-gpl
   libavutil      52. 46.100 / 52. 46.100
   libavcodec     55. 33.101 / 55. 33.101
   libavformat    55. 18.104 / 55. 18.104
   libavdevice    55.  3.100 / 55.  3.100
   libavfilter     3. 88.100 /  3. 88.100
   libswscale      2.  5.100 /  2.  5.100
   libswresample   0. 17.103 /  0. 17.103
   libpostproc    52.  3.100 / 52.  3.100
 [avi @ 0x2809880] parser not found for codec msvideo1, packets or times
 may be invalid.
     Last message repeated 1 times
 Input #0, avi, from 'fate-suite/cram/skating.avi':
   Duration: 00:00:07.50, start: 0.000000, bitrate: 648 kb/s
     Stream #0:0: Video: msvideo1 (CRAM / 0x4D415243), pal8, 160x120, 30
 tbr, 30 tbn, 30 tbc
 [Parsed_scale_1 @ 0x280d800] w:200 h:200 flags:'0x4' interl:0
 [graph 0 input from stream 0:0 @ 0x280ea60] w:160 h:120 pixfmt:pal8
 tb:10000/300003 fr:300003/10000 sar:0/1 sws_param:flags=2
 [auto-inserted scaler 0 @ 0x27f48a0] w:iw h:ih flags:'0x4' interl:0
 [Parsed_yadif_0 @ 0x280d0e0] auto-inserting filter 'auto-inserted scaler
 0' between the filter 'graph 0 input from stream 0:0' and the filter
 'Parsed_yadif_0'
 [auto-inserted scaler 0 @ 0x27f48a0] w:160 h:120 fmt:pal8 sar:0/1 -> w:160
 h:120 fmt:gray sar:0/1 flags:0x4
 [Parsed_scale_1 @ 0x280d800] w:160 h:120 fmt:gray sar:0/1 -> w:200 h:200
 fmt:yuv420p sar:0/1 flags:0x4
 Output #0, flv, to 'out.flv':
   Metadata:
     encoder         : Lavf55.18.104
     Stream #0:0: Video: flv1 (flv) ([2][0][0][0] / 0x0002), yuv420p,
 200x200, q=2-31, 200 kb/s, 1k tbn, 30 tbc
 Stream mapping:
   Stream #0:0 -> #0:0 (msvideo1 -> flv)
 Press [q] to stop, [?] for help
 No more output streams to write to, finishing.
 frame=  225 fps=0.0 q=5.7 Lsize=     254kB time=00:00:07.50 bitrate=
 276.9kbits/s
 video:250kB audio:0kB subtitle:0 global headers:0kB muxing overhead
 1.490064%
 }}}
 out.flv is gray because the first inserted scaler uses pix_fmt gray.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/3008#comment:1>
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