[Libquicktime-devel] quicktime_is_bframe() breaking for wobbly GOP pattern

[Derek C. <der...@mi...>]

Hi,

I've come across an XDCAM file with an unusual GOP pattern that breaks the
current logic of quicktime_is_bframe() (see related notes in
http://sourceforge.net/p/libquicktime/mailman/message/29389235/) , meaning
seeking to certain frames 'resync's badly for the FFmpeg plugin:

     composition time to sample (ctts)
      version 0
      flags 0
      total_entries 46437
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 0  <--- flagged as a B-frame however bitstream flag
reveals this is an I-frame
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 2
       count 2 duration -1
       count 1 duration 1
       count 1 duration -1
       count 1 duration 0  <--- flagged as a B-frame however bitstream flag
reveals this is an I-frame
...

Any ideas what to do about this?

Thanks,
-- 



Derek Chow / C++ Developer

der...@mi... / +44(0)7825373230

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