On Sun, May 29, 2011 at 10:40 AM, Yusuke Nakamura
<[email protected]> wrote:
> 2011/5/28 Gil Pedersen <[email protected]>
>
>>
>> The current code assumes that the first sample has the earliest
>> composition time. When using b-frames, a codec is not required to enforce
>> this, and thus I make a quick search for the sample with the earliest
>> composition time. ISO/IEC 14496-12 section 8.6.1.1 has an open GOP example
>> that illustrates this. As far as I can tell this composition time is what
>> needs to go into "media_time" for proper sync.
>
> Do you wish to start presentation from incomplete samples such as
> undecodable leading samples, which are samples that have earlier composition
> time than the reference I-frame has, and depend on the earlier GOP deleted
> from the stream?
>
> I think incomplete samples shouldn't be in any edit, i.e. whole
> presentation, and you should add more delay by sum of duration of these
> incomplete samples and set composition time of the reference I-frame to
> media_time of second edit entry.
>
> So, I think it is enough for you to only set track->cluster[0].cts to
> segment_duration of the first edit with timescale conversion and to
> media_time of the second edit.
>

I tend to agree with Nakamura-san's analysis of this.

Are B1 and B2 from the Open GOP example supposed to be decodable
without reference pictures before I1?

Thanks,
Alex
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