[FFmpeg-trac] #764(avcodec:new): Increasing robustness of runlength decoding for scantable access in mpeg12.c

[FFmpeg]

#764: Increasing robustness of runlength decoding for scantable access in
mpeg12.c
-------------------------------------+-------------------------------------
             Reporter:  erik         |                    Owner:
                 Type:  defect       |                   Status:  new
             Priority:  normal       |                Component:  avcodec
              Version:  unspecified  |               Resolution:
             Keywords:  mpeg         |               Blocked By:
  robustness                         |  Reproduced by developer:  0
             Blocking:               |
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------

Comment (by erik):

 One more question.
 Can valgrind find errors in pointer calculation?
 Part of the scantable access is done by type array indexing but the last
 use case is done by pointer arithmic

 Code fragment from mpeg12.c:

      uint8_t * scantable = s->intra_scantable.permutated;
 ....
              if (level == 127) {
                  break;
              } else if (level != 0) {
                 scantable += run;
                 j = *scantable;

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/764#comment:9>
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