mjpeg: artefacts with 12bpp grayscale in low quality

[ami_stuff]

some artefacts (at the left side) are visible when quality of jpeg image is lower that 50%

knoppix@Microknoppix:/media/sdb1$ ffmpeg -i 30.jpg out.bmp
ffmpeg version 2.0-bbcaf25 Copyright (c) 2000-2013 the FFmpeg developers
  built on Sep 12 2013 00:30:03 with gcc 4.7 (Debian 4.7.2-5)
  configuration: --disable-yasm --disable-ffprobe --disable-ffserver --enable-gpl
  libavutil      52. 43.100 / 52. 43.100
  libavcodec     55. 31.101 / 55. 31.101
  libavformat    55. 16.102 / 55. 16.102
  libavdevice    55.  3.100 / 55.  3.100
  libavfilter     3. 84.100 /  3. 84.100
  libswscale      2.  5.100 /  2.  5.100
  libswresample   0. 17.103 /  0. 17.103
  libpostproc    52.  3.100 / 52.  3.100
Input #0, image2, from '30.jpg':
  Duration: 00:00:00.04, start: 0.000000, bitrate: N/A
    Stream #0:0: Video: mjpeg, gray16le(12 bpc), 1356x1588 [SAR 72:72 DAR 339:397], 25 tbr, 25 tbn, 25 tbc
Output #0, image2, to 'out.bmp':
  Metadata:
    encoder         : Lavf55.16.102
    Stream #0:0: Video: bmp, gray, 1356x1588 [SAR 1:1 DAR 339:397], 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=0.0 q=-1.0 Lsize=N/A time=00:00:00.04 bitrate=N/A    
video:2104kB audio:0kB subtitle:0 global headers:0kB muxing overhead -100.001021%

[Carl Eugen Hoyos]

$ ./djpeg 10.jpg >out.pnm
Bogus Huffman table definition

[ami_stuff]

At first I have found this problem with sample from this report:

​http://java.net/jira/browse/JAI_IMAGEIO_CORE-79

then I tried to reproduce it myself.

[Carl Eugen Hoyos]

Replying to ami_stuff:

At first I have found this problem with sample from this report:

​http://java.net/jira/browse/JAI_IMAGEIO_CORE-79

Could you upload the "sample"? I can't reach the site.

[ami_stuff]

attached

[Carl Eugen Hoyos]

No artefacts with libjpeg-v6b.

[Michael Niedermayer]

Should be fixed in 529540759f285f251a198b6f55bb8cd451ab28e8