[FFmpeg-trac] #4445(undetermined:reopened): H264 with VUI overread fails to decode

[FFmpeg]

#4445: H264 with VUI overread fails to decode
-------------------------------------+-------------------------------------
             Reporter:  michael      |                    Owner:
                 Type:  defect       |                   Status:  reopened
             Priority:  normal       |                Component:
              Version:  git-master   |  undetermined
             Keywords:  h264         |               Resolution:
             Blocking:               |               Blocked By:
Analyzed by developer:  0            |  Reproduced by developer:  0
-------------------------------------+-------------------------------------
Changes (by projectsymphony):

 * status:  closed => reopened
 * resolution:  fixed =>


Comment:

 Partially related to this, a sample which reports

 `[h264 @ 0x7fcff900d600] time_scale/num_units_in_tick invalid or
 unsupported (0/2)`

 triggers the same problem (unreferenced sps/pps). Skipping the immediate
 return at h264_ps.c:200 makes the video work again. The error is correct
 since time_scale and num_units_in_tick need to be > 0, however it might be
 overkill to block decoding in my opinion: I prepared a patch that ignores
 the error and sets the present_flag to 0, so that those values are not
 used at all.

 Unfortunately sample is not available, but I know the source: it's coming
 from a windows phone recording

 `Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661),
 yuv420p(tv), 144x176, 46 kb/s, 6.64 fps, 10 tbr, 10k tbn, 20k tbc
 (default)`

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Ticket URL: <https://trac.ffmpeg.org/ticket/4445#comment:7>
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