HEVC decoding regression with SAODBLK conformance samples

[Carl Eugen Hoyos]

​http://ffmpeg.org/pipermail/ffmpeg-user/2017-November/038065.html
Two hevc conformance tests do not decode correctly since fa0506e4136b5b883205c82809a113f5edcd200b
​http://wftp3.itu.int/av-arch/jctvc-site/bitstream_exchange/draft_conformance/HEVC_v1/SAODBLK_A_MainConcept_4.zip
​http://wftp3.itu.int/av-arch/jctvc-site/bitstream_exchange/draft_conformance/HEVC_v1/SAODBLK_B_MainConcept_4.zip
For the first sample, the first (I) frame shows the difference, for the second sample, the following P frame is also needed to show an issue.

$ ffmpeg -i SAODBLK_A_MainConcept_4.bin -vframes 1 -f crc -
ffmpeg version N-89317-gda49cdf Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 6.3.0 (GCC)
  configuration: --enable-gpl
  libavutil      56.  3.100 / 56.  3.100
  libavcodec     58.  6.101 / 58.  6.101
  libavformat    58.  2.103 / 58.  2.103
  libavdevice    58.  0.100 / 58.  0.100
  libavfilter     7.  5.100 /  7.  5.100
  libswscale      5.  0.101 /  5.  0.101
  libswresample   3.  0.101 /  3.  0.101
  libpostproc    55.  0.100 / 55.  0.100
Input #0, hevc, from 'SAODBLK_A_MainConcept_4.bin':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: hevc (Main), yuv420p(tv), 1016x760, 25 fps, 25 tbr, 1200k tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (hevc (native) -> rawvideo (native))
Press [q] to stop, [?] for help
Output #0, crc, to 'pipe:':
  Metadata:
    encoder         : Lavf58.2.103
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1016x760, q=2-31, 231648 kb/s, 25 fps, 25 tbn, 25 tbc
    Metadata:
      encoder         : Lavc58.6.101 rawvideo
CRC=0xa2d6b6e6
frame=    1 fps=0.0 q=-0.0 Lsize=       0kB time=00:00:00.04 bitrate=   3.0kbits/s speed=1.61x
video:1131kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

$ ffmpeg -i SAODBLK_B_MainConcept_4.bin -vframes 2 -f crc -
ffmpeg version N-89317-gda49cdf Copyright (c) 2000-2017 the FFmpeg developers
  built with gcc 6.3.0 (GCC)
  configuration: --enable-gpl
  libavutil      56.  3.100 / 56.  3.100
  libavcodec     58.  6.101 / 58.  6.101
  libavformat    58.  2.103 / 58.  2.103
  libavdevice    58.  0.100 / 58.  0.100
  libavfilter     7.  5.100 /  7.  5.100
  libswscale      5.  0.101 /  5.  0.101
  libswresample   3.  0.101 /  3.  0.101
  libpostproc    55.  0.100 / 55.  0.100
Input #0, hevc, from 'SAODBLK_B_MainConcept_4.bin':
  Duration: N/A, bitrate: N/A
    Stream #0:0: Video: hevc (Main), yuv420p(tv), 1016x760, 25 fps, 25 tbr, 1200k tbn, 25 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (hevc (native) -> rawvideo (native))
Press [q] to stop, [?] for help
Output #0, crc, to 'pipe:':
  Metadata:
    encoder         : Lavf58.2.103
    Stream #0:0: Video: rawvideo (I420 / 0x30323449), yuv420p, 1016x760, q=2-31, 231648 kb/s, 25 fps, 25 tbn, 25 tbc
    Metadata:
      encoder         : Lavc58.6.101 rawvideo
CRC=0x1f5fb75f
frame=    2 fps=0.0 q=-0.0 Lsize=       0kB time=00:00:00.08 bitrate=   1.5kbits/s speed=1.23x
video:2262kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown

[Balling]

P.S. Oh, it is just a deblocking regression.

https://ffmpeg.org/pipermail/ffmpeg-user/2017-November/038072.html