Errors shown when correctly decoding jpeg2000 frames

[cehoyos]

Errors are shown when decoding jpeg2000 frames since a85b02dcf70f62a6a433a607143f1f78fa5648bb

$ ffmpeg -f lavfi -i testsrc=d=1 -pred 1 -vframes 1 out.j2k

$ ffmpeg -i out.j2k -f crc -
ffmpeg version N-79105-gdf34b70 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl
  libavutil      55. 19.100 / 55. 19.100
  libavcodec     57. 28.103 / 57. 28.103
  libavformat    57. 28.102 / 57. 28.102
  libavdevice    57.  0.101 / 57.  0.101
  libavfilter     6. 39.102 /  6. 39.102
  libswscale      4.  0.100 /  4.  0.100
  libswresample   2.  0.101 /  2.  0.101
  libpostproc    54.  0.100 / 54.  0.100
[jpeg2000 @ 0x2011960] bpno became negative
    Last message repeated 365 times
Input #0, j2k_pipe, from 'out.j2k':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: jpeg2000 (JPEG 2000 codestream restriction 0), rgb24, 320x240, lossless, 25 tbr, 25 tbn, 25 tbc
Output #0, crc, to 'pipe:':
  Metadata:
    encoder         : Lavf57.28.102
    Stream #0:0: Video: rawvideo (RGB[24] / 0x18424752), rgb24, 320x240, q=2-31, 200 kb/s, 25 fps, 25 tbn, 25 tbc
    Metadata:
      encoder         : Lavc57.28.103 rawvideo
Stream mapping:
  Stream #0:0 -> #0:0 (jpeg2000 (native) -> rawvideo (native))
Press [q] to stop, [?] for help
[jpeg2000 @ 0x202e0a0] bpno became negative
    Last message repeated 365 times
CRC=0x0d00d19b
frame=    1 fps=0.0 q=-0.0 Lsize=       0kB time=00:00:00.04 bitrate=   3.0kbits/s speed=1.74x
video:225kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

Decoding is still bit-exact.