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

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

One idea I have is to assume the previous to simply compare the previous
ctts entry (see attached patch).


On 3 March 2014 10:36, Derek Chow <der...@mi...> wrote:

> 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
>
> Office +44 (0)207 884 2530
> 21 Broadwall, London, SE1 9PL, United Kingdom
> http://www.mirriad.com
>



-- 



Derek Chow / C++ Developer

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

Office +44 (0)207 884 2530
21 Broadwall, London, SE1 9PL, United Kingdom
http://www.mirriad.com