[FFmpeg-trac] #7174(avcodec:open): H.264 decoding turns blocky, "Out of range weight"+"decode_slice_header error"+more

[FFmpeg]

#7174: H.264 decoding turns blocky, "Out of range weight"+"decode_slice_header
error"+more
-------------------------------------+-------------------------------------
             Reporter:  sneaker      |                    Owner:
                 Type:  defect       |                   Status:  open
             Priority:  important    |                Component:  avcodec
              Version:  git-master   |               Resolution:
             Keywords:  h264         |               Blocked By:
  regression                         |
             Blocking:               |  Reproduced by developer:  1
Analyzed by developer:  0            |
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Comment (by dmerg):

 I have come across this decoding error in some h264 video. In both the
 sample linked here and in my videos, the actual out-of-range weight is
 just one luma_weight value, -129 (as a signed int). This smells like a
 off-by-one error given the spec, but I've not been able to determine if
 it's in ffmpeg or a buggy x264 encoder/source file.

 Normalizing the weights in ff_h264_pred_weight_table() to within spec
 (-129 -> -128) allows the linked sample and videos to decode without
 error.

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Ticket URL: <https://trac.ffmpeg.org/ticket/7174#comment:3>
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