YUV video to RGB image export color conversion issue

[Peter B.]

When extracting images from the video (yuv422p), the color values in
the interlaced areas of the video are deviate from their original
beyond recognition.

Image comparisons and the original video can be found at:
​http://download.das-werkstatt.com/pb/mthk/examples/color_problem/problem.html

[Peter B.]

Patch to fix this (by Baptiste Coudurier)

[Peter B.]

Baptiste Coudurier posted a patch on the ffmpeg-user mailing list. I've applied this patch to git-ff1efc5 and verfified that it fixes this issue.

[Peter B.]

I'm reopening this issue since the patch is currently not applied to upstream, because as Michael Niedermayer mentions ​in a post on the devel-mailinglist:

[quote]
the patch causes speed loss. Thats ok for 422 but the code is also
used for 420 where there is speedloss but no quality gain

iam not sure how to solve this
[quote]

[Carl Eugen Hoyos]

Please post a command line, complete, uncut output (and a sample)?

[Peter B.]

It's been a while since I've had this on my table, so I can't post the exact ffmpeg-commandline I've used right now. I'll post them here as soon as I get to it.

The video sample I've used to test this, is located at:
​http://download.das-werkstatt.com/pb/mthk/examples/color_problem/testvideo_color_rectangles-YUV422P.avi
(Encoding FFv1 PAL-SD resolution 720x576@25fps)

If you try to export the frames of the above video as RGB images (e.g. png, jpg) you will always get the colors interpolated between the fields.

Image samples can be found at:
​http://download.das-werkstatt.com/pb/mthk/examples/color_problem/problem.html

[Carl Eugen Hoyos]

Please post a command line and complete, uncut output.

[Carl Eugen Hoyos]

Is this still reproducible or was this fixed in ​http://git.videolan.org/?p=ffmpeg.git;a=commit;h=5aa70309ad236cf7e218cdce913d8290aae04d4a ?

[Peter B.]

I've checked ​the mailing list archives, and the command line used was:

ffmpeg -vframes 4 -i 'testvideo_color_rectangles-YUV422P.avi' -pix_fmt rgb24 -f image2 '%03d.bmp'

I've tried right now, and the error still persists: The colors are still wrongly interpolated.

FFmpeg version:

Git ​2169f971ad9b582cc3f1e6a1430aad44d64495d3 (10 Jan 2012 06:15:18)

Uncut output:

ffmpeg version N-36659-g2169f97 Copyright (c) 2000-2012 the FFmpeg developers
  built on Jan 10 2012 14:29:42 with gcc 4.4.5
  configuration: --prefix=/usr/local --enable-gpl --enable-nonfree --enable-postproc --enable-swscale --enable-avfilter --enable-pthreads --enable-bzlib --enable-libmp3lame --enable-libvorbis --enable-libxvid --enable-zlib --enable-libopenjpeg --enable-decoder=png --enable-encoder=png --enable-libdirac --enable-libschroedinger
  libavutil      51. 34.100 / 51. 34.100
  libavcodec     53. 54.100 / 53. 54.100
  libavformat    53. 29.100 / 53. 29.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 58.100 /  2. 58.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    51.  2.100 / 51.  2.100
Input #0, avi, from 'testvideo_color_rectangles-YUV422P.avi':
  Duration: 00:00:00.40, start: 0.000000, bitrate: 868 kb/s
    Stream #0:0: Video: ffv1 (FFV1 / 0x31564646), yuv422p, 720x576, 10 tbr, 10 tbn, 10 tbc
Incompatible pixel format 'rgb24' for codec 'bmp', auto-selecting format 'bgr24'
[buffer @ 0xa336f80] w:720 h:576 pixfmt:yuv422p tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 0xa3385c0] auto-inserting filter 'auto-inserted scale 0' between the filter 'src' and the filter 'out'
[scale @ 0xa330d80] w:720 h:576 fmt:yuv422p -> w:720 h:576 fmt:bgr24 flags:0x4
[swscaler @ 0xa3311c0] No accelerated colorspace conversion found from yuv422p to bgr24.
[swscaler @ 0xa3463e0] No accelerated colorspace conversion found from yuv422p to bgr24.
[swscaler @ 0xa34ae60] No accelerated colorspace conversion found from yuv422p to bgr24.
Output #0, image2, to '%03d.bmp':
  Metadata:
    encoder         : Lavf53.29.100
    Stream #0:0: Video: bmp, bgr24, 720x576, q=2-31, 200 kb/s, 90k tbn, 10 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (ffv1 -> bmp)
Press [q] to stop, [?] for help
frame=    4 fps=  0 q=0.0 Lsize=       0kB time=00:00:00.40 bitrate=   0.0kbits/s
video:4860kB audio:0kB global headers:0kB muxing overhead -100.000000%

[Peter B.]

Additionally, Baptiste's patch cannot be applied to the current git version anymore, as the code has changed too much since the version the patch was written for (SVN revision 32669).

[Carl Eugen Hoyos]

$ ffmpeg -i yuvj422.jpg out.bmp
ffmpeg version N-36662-g93d49cb Copyright (c) 2000-2012 the FFmpeg developers
  built on Jan 10 2012 19:07:13 with gcc 4.5.3
  configuration: --cc='/usr/local/gcc-4.5.3/bin/gcc -m32'
  libavutil      51. 34.100 / 51. 34.100
  libavcodec     53. 54.100 / 53. 54.100
  libavformat    53. 29.100 / 53. 29.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 58.100 /  2. 58.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
Input #0, image2, from 'yuvj422.jpg':
  Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: mjpeg, yuvj422p, 720x576, 25 tbr, 25 tbn, 25 tbc
Incompatible pixel format 'yuvj422p' for codec 'bmp', auto-selecting format 'bgr24'
[buffer @ 0x8dd8000] w:720 h:576 pixfmt:yuvj422p tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 0x8dd8d20] auto-inserting filter 'auto-inserted scale 0' between the filter 'src' and the filter 'out'
[scale @ 0x8dd9240] w:720 h:576 fmt:yuvj422p -> w:720 h:576 fmt:bgr24 flags:0x4
[swscaler @ 0x8de4280] No accelerated colorspace conversion found from yuv422p to bgr24.
[swscaler @ 0x8dee060] No accelerated colorspace conversion found from yuv422p to bgr24.
[swscaler @ 0x8df2b00] No accelerated colorspace conversion found from yuv422p to bgr24.
Output #0, image2, to 'out.bmp':
  Metadata:
    encoder         : Lavf53.29.100
    Stream #0:0: Video: bmp, bgr24, 720x576, q=2-31, 200 kb/s, 90k tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg -> bmp)
Press [q] to stop, [?] for help
frame=    1 fps=  0 q=0.0 Lsize=       0kB time=00:00:00.04 bitrate=   0.0kbits/s
video:1215kB audio:0kB global headers:0kB muxing overhead -100.000000%

[Peter B.]

RGB output from source: yuvj422.jpg

[Peter B.]

I'm not sure what you're trying to tell me... ;)
I've reproduced your conversion and attached the resulting RGB as PNG (not BMP, due to filesize issues):
yuvj422jpg-N-36728-g794006f.png​
The colors are also wrong when converting the JPEG.

$ ffmpeg -i yuvj422.jpg out/out.png

ffmpeg version N-36728-g794006f Copyright (c) 2000-2012 the FFmpeg developers
  built on Jan 12 2012 09:16:04 with gcc 4.4.5
  configuration: --prefix=/usr/local --enable-gpl --enable-nonfree --enable-postproc --enable-swscale --enable-avfilter --enable-pthreads --enable-bzlib --enable-libmp3lame --enable-libvorbis --enable-libxvid --enable-zlib --enable-libopenjpeg --enable-decoder=png --enable-encoder=png --enable-libdirac --enable-libschroedinger
  libavutil      51. 34.100 / 51. 34.100
  libavcodec     53. 55.100 / 53. 55.100
  libavformat    53. 29.100 / 53. 29.100
  libavdevice    53.  4.100 / 53.  4.100
  libavfilter     2. 58.100 /  2. 58.100
  libswscale      2.  1.100 /  2.  1.100
  libswresample   0.  6.100 /  0.  6.100
  libpostproc    51.  2.100 / 51.  2.100
Input #0, image2, from 'yuvj422.jpg':
  Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: mjpeg, yuvj422p, 720x576, 25 tbr, 25 tbn, 25 tbc
Incompatible pixel format 'yuvj422p' for codec 'png', auto-selecting format 'rgb24'
[buffer @ 0x9351e20] w:720 h:576 pixfmt:yuvj422p tb:1/1000000 sar:0/1 sws_param:
[buffersink @ 0x93487e0] auto-inserting filter 'auto-inserted scale 0' between the filter 'src' and the filter 'out'
[scale @ 0x9348d40] w:720 h:576 fmt:yuvj422p -> w:720 h:576 fmt:rgb24 flags:0x4
[swscaler @ 0x9357b60] No accelerated colorspace conversion found from yuv422p to rgb24.
[swscaler @ 0x9367800] No accelerated colorspace conversion found from yuv422p to rgb24.
[swscaler @ 0x936d2a0] No accelerated colorspace conversion found from yuv422p to rgb24.
Output #0, image2, to 'out/out.png':
  Metadata:
    encoder         : Lavf53.29.100
    Stream #0:0: Video: png, rgb24, 720x576, q=2-31, 200 kb/s, 90k tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mjpeg -> png)
Press [q] to stop, [?] for help
frame=    1 fps=  0 q=0.0 Lsize=       0kB time=00:00:00.04 bitrate=   0.0kbits/s
video:5kB audio:0kB global headers:0kB muxing overhead -100.000000%

[Carl Eugen Hoyos]

Replying to peter_b:

I'm not sure what you're trying to tell me... ;)

In August, I asked for a command line (and complete, uncut console output) and a sample.

You added a command line (and the console output) two days ago, I was able to reproduce your issue, I set the "Reproduced"-flag and I added a sample.

I did not ask for the resulting RGB file because I do not remember an issue where attaching the resulting file made reproducing the issue easier.

I hope that clears it up ;-)

[Peter B.]

Understood.
Thanks.

[Michael Niedermayer]

It appears this has been fixed by some change since it was reported, i cant reproduce it anymore