id,summary,reporter,owner,description,type,status,priority,component,version,resolution,keywords,cc,blockedby,blocking,reproduced,analyzed
225,Converting from YUVJ to YUV lose contrast,sghpunk,,"I am trying to transcode video from my Nicon D90 mjpeg to x264.
And output video contrast is lower than input.
I use ffmpeg-HEAD-27614b1

Command line:
ffmpeg.exe -threads 2 -an -i input.mkv -f matroska -vcodec libx264 -profile main -preset fast -cqp 27 -y x264-low_contract_yuv.mkv > enc.log 2>&1
{{{
ffmpeg version UNKNOWN, Copyright (c) 2000-2011 the FFmpeg developers
  built on May 19 2011 17:41:01 with gcc 4.5.2
  configuration: --prefix=/mingw --disable-static --enable-shared --enable-gpl --enable-version3 --disable-doc --enable-postproc --disable-network --enable-memalign-hack --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libmp3lame --enable-libspeex --enable-libvorbis --enable-libx264 --enable-pthreads --enable-frei0r --extra-cflags='-mthreads -mtune=nocona -march=nocona -msse3 -m80387 -mfpmath=387 -O2 -fgnu89-inline -Wno-error=missing-prototypes' --extra-ldflags='-Wl,--enable-auto-image-base -Wl,--enable-auto-import' --extra-libs=-ldl --cpu=nocona
  libavutil    51.  2. 1 / 51.  2. 1
  libavcodec   53.  5. 0 / 53.  5. 0
  libavformat  53.  0. 3 / 53.  0. 3
  libavdevice  53.  0. 0 / 53.  0. 0
  libavfilter   2.  5. 0 /  2.  5. 0
  libswscale    0. 14. 0 /  0. 14. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[matroska,webm @ 00b70280] Estimating duration from bitrate, this may be inaccurate
Input #0, matroska,webm, from 'input.mkv':
  Metadata:
    MAKER           : NIKON CORPORATION
    MODEL           : NIKON D90
    CREATION_TIME   : 2011-05-05 07:47:28
    ENCODER         : Lavf53.0.3
  Duration: 00:00:05.04, start: 0.000000, bitrate: N/A
    Stream #0.0: Video: mjpeg, yuvj422p, 1280x720, PAR 1:1 DAR 16:9, 24 fps, 24 tbr, 1k tbn, 24 tbc (default)
Incompatible pixel format 'yuvj422p' for codec 'libx264', auto-selecting format 'yuv420p'
[buffer @ 00b83e00] w:1280 h:720 pixfmt:yuvj422p tb:1/1000000 sar:1/1
[ffsink @ 003efee0] auto-inserting filter 'auto-inserted scaler 0' between the filter 'src' and the filter 'out'
[scale @ 00b95920] w:1280 h:720 fmt:yuvj422p -> w:1280 h:720 fmt:yuv420p flags:0xa0000004
[libx264 @ 00b60540] using SAR=1/1
[libx264 @ 00b60540] using cpu capabilities: MMX2 SSE2 SSE3 Cache64
[libx264 @ 00b60540] profile Main, level 3.1
[libx264 @ 00b60540] 264 - core 114 - H.264/MPEG-4 AVC codec - Copyleft 2003-2011 - http://www.videolan.org/x264.html - options: cabac=1 ref=2 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=6 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=1 keyint=250 keyint_min=24 scenecut=40 intra_refresh=0 rc=cqp mbtree=0 qp=27 ip_ratio=1.40 pb_ratio=1.30 aq=0
Output #0, matroska, to 'x264-low_contract_yuv.mkv':
  Metadata:
    MAKER           : NIKON CORPORATION
    MODEL           : NIKON D90
    CREATION_TIME   : 2011-05-05 07:47:28
    encoder         : Lavf53.0.3
    Stream #0.0: Video: libx264, yuv420p, 1280x720 [PAR 1:1 DAR 16:9], q=2-31, 200 kb/s, 1k tbn, 24 tbc (default)
Stream mapping:
  Stream #0.0 -> #0.0
Press [q] to stop, [?] for help
frame=   10 fps=  0 q=27.0 size=      33kB time=10000000000.00 bitrate=   0.0kbits/s    
...CUT...
frame=  121 fps=  5 q=-1.0 Lsize=     864kB time=4.96 bitrate=1427.9kbits/s    
video:863kB audio:0kB global headers:0kB muxing overhead 0.173612%
frame I:1     Avg QP:24.00  size: 33897
[libx264 @ 00b60540] frame P:41    Avg QP:27.00  size: 10846
[libx264 @ 00b60540] frame B:79    Avg QP:28.66  size:  5118
[libx264 @ 00b60540] consecutive B-frames:  6.6% 11.6% 22.3% 59.5%
[libx264 @ 00b60540] mb I  I16..4: 44.1%  0.0% 55.9%
[libx264 @ 00b60540] mb P  I16..4:  7.9%  0.0%  4.9%  P16..4: 42.7% 10.5%  3.3%  0.0%  0.0%    skip:30.7%
[libx264 @ 00b60540] mb B  I16..4:  3.9%  0.0%  0.6%  B16..8: 30.6%  7.4%  0.3%  direct: 8.4%  skip:48.7%  L0:41.1% L1:53.7% BI: 5.2%
[libx264 @ 00b60540] coded y,uvDC,uvAC intra: 29.7% 47.0% 14.1% inter: 8.7% 11.9% 0.1%
[libx264 @ 00b60540] i16 v,h,dc,p: 31% 31% 24% 14%
[libx264 @ 00b60540] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 26% 20% 20%  5%  7%  7%  6%  6%  3%
[libx264 @ 00b60540] i8c dc,h,v,p: 63% 18% 16%  3%
[libx264 @ 00b60540] Weighted P-Frames: Y:2.4% UV:2.4%
[libx264 @ 00b60540] ref P L0: 75.4% 24.6%
[libx264 @ 00b60540] ref B L0: 80.3% 19.7%
[libx264 @ 00b60540] ref B L1: 94.1%  5.9%
[libx264 @ 00b60540] kb/s:1401.04
}}}
ffmpeg -v 9 -loglevel 99 -i input.mkv > v9.log 2>&1
{{{
ffmpeg version UNKNOWN, Copyright (c) 2000-2011 the FFmpeg developers
  built on May 19 2011 17:41:01 with gcc 4.5.2
  configuration: --prefix=/mingw --disable-static --enable-shared --enable-gpl --enable-version3 --disable-doc --enable-postproc --disable-network --enable-memalign-hack --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libmp3lame --enable-libspeex --enable-libvorbis --enable-libx264 --enable-pthreads --enable-frei0r --extra-cflags='-mthreads -mtune=nocona -march=nocona -msse3 -m80387 -mfpmath=387 -O2 -fgnu89-inline -Wno-error=missing-prototypes' --extra-ldflags='-Wl,--enable-auto-image-base -Wl,--enable-auto-import' --extra-libs=-ldl --cpu=nocona
  libavutil    51.  2. 1 / 51.  2. 1
  libavcodec   53.  5. 0 / 53.  5. 0
  libavformat  53.  0. 3 / 53.  0. 3
  libavdevice  53.  0. 0 / 53.  0. 0
  libavfilter   2.  5. 0 /  2.  5. 0
  libswscale    0. 14. 0 /  0. 14. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[NULL @ 00b70280] Format matroska,webm probed with size=2048 and score=100
st:0 removing common factor 1000000 from timebase
[mjpeg @ 00b7b700] buffer too small, expanding to 73330 bytes
[mjpeg @ 00b7b700] marker=d8 avail_size_in_buf=73330
[mjpeg @ 00b7b700] marker parser used 0 bytes (0 bits)
[mjpeg @ 00b7b700] marker=db avail_size_in_buf=73328
[mjpeg @ 00b7b700] index=0
[mjpeg @ 00b7b700] qscale[0]: 3
[mjpeg @ 00b7b700] index=1
[mjpeg @ 00b7b700] qscale[1]: 6
[mjpeg @ 00b7b700] marker parser used 132 bytes (1056 bits)
[mjpeg @ 00b7b700] marker=c0 avail_size_in_buf=73194
[mjpeg @ 00b7b700] sof0: picture: 1280x720
[mjpeg @ 00b7b700] component 0 2:1 id: 0 quant:0
[mjpeg @ 00b7b700] component 1 1:1 id: 1 quant:1
[mjpeg @ 00b7b700] component 2 1:1 id: 2 quant:1
[mjpeg @ 00b7b700] pix fmt id 21111100
[mjpeg @ 00b7b700] marker parser used 17 bytes (136 bits)
[mjpeg @ 00b7b700] marker=c4 avail_size_in_buf=73175
[mjpeg @ 00b7b700] class=0 index=0 nb_codes=12
[mjpeg @ 00b7b700] class=1 index=0 nb_codes=251
[mjpeg @ 00b7b700] class=0 index=1 nb_codes=12
[mjpeg @ 00b7b700] class=1 index=1 nb_codes=251
[mjpeg @ 00b7b700] marker parser used 418 bytes (3344 bits)
[mjpeg @ 00b7b700] escaping removed 115 bytes
[mjpeg @ 00b7b700] marker=da avail_size_in_buf=72755
[mjpeg @ 00b7b700] component: 0
[mjpeg @ 00b7b700] component: 1
[mjpeg @ 00b7b700] component: 2
[mjpeg @ 00b7b700] marker parser used 72639 bytes (581110 bits)
[mjpeg @ 00b7b700] marker=d9 avail_size_in_buf=3
[mjpeg @ 00b7b700] mjpeg decode frame unused 3 bytes
[matroska,webm @ 00b70280] All info found
[matroska,webm @ 00b70280] Estimating duration from bitrate, this may be inaccurate
Input #0, matroska,webm, from 'input.mkv':
  Metadata:
    MAKER           : NIKON CORPORATION
    MODEL           : NIKON D90
    CREATION_TIME   : 2011-05-05 07:47:28
    ENCODER         : Lavf53.0.3
  Duration: 00:00:05.04, start: 0.000000, bitrate: N/A
    Stream #0.0, 1, 1/1000: Video: mjpeg, yuvj422p, 1280x720, 1/24, PAR 1:1 DAR 16:9, 24 fps, 24 tbr, 1k tbn, 24 tbc (default)
At least one output file must be specified
}}}

Seems like contrast loosing when converting a pixel format from yuvj422p to yuv420p. 
I tryed to encode same video from mplayer yuv4mpeg raw file and in this case contrast on output video is the same.

I cannot find mplayer ftp server to upload samples. Where can I upload it?",defect,open,normal,swscale,git-master,,YUV/YUVJ contrast,,,,0,0