[FFmpeg-trac] #2970(avcodec:open): White line in top macroblock of dvvideo

FFmpeg trac at avcodec.org
Thu Aug 14 13:57:52 CEST 2014

#2970: White line in top macroblock of dvvideo
             Reporter:  cehoyos     |                    Owner:
                 Type:  defect      |                   Status:  open
             Priority:  normal      |                Component:  avcodec
              Version:  git-master  |               Resolution:
             Keywords:  dvvideo     |               Blocked By:
             Blocking:              |  Reproduced by developer:  1
Analyzed by developer:  0           |

Comment (by kurosu):

 For info, the sequence is SD 4:2:2, and the strange blocks are all coded
 as 2x4x8 (as in interlaced), ie dct_mode=1 at dvdec.c:205

 By using factor_table as it was dct_mode=0, the decoded result looks much
 better. It is possible that the quantization scale derivation may be wrong
 in case of 4:2:2. I couldn't decipher what to make of section 5.3/figure
 28/table 23 here, and the whole code is somewhat hard to follow.

Ticket URL: <https://trac.ffmpeg.org/ticket/2970#comment:2>
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