Re: [Libquicktime-devel] New Demultiplexing mode

[Burkhard P. <pl...@ig...>]

Hi,

Am 09.04.2014 21:46, schrieb Erik Johansson:
> Hi Burkhard,
>
>> The solution is to unpack the indices (stts, ctts, stco, stsc,
>> stss and stps) and make one single index table from them.
>
> Incidentally, I was writing code to create such an index outside of
> libquicktime just the other day. Nice to have support for it in the
> library! :-)

Of course we can think of exporting the index information somehow in the
public API.

>> In the meantime you can help a bit by calling qtdump on your files (ideally
>> with really weird GOP patterns) and check if the generated index makes sense.
>
> I've given it a spin across a selection of the more convoluted files I
> have at hand. It holds up just fine so far.

Good. I also tested it with H.264 streams with B-Pyramids. As far as I see,
the reference B-Frames are correctly detected also.

What I don't have at hand are files with stps atoms (partial sync sample).

> While on the topic of indexes... I've lately come across a few files
> from different sources that makes use of multiple entries in the stsd
> sample descriptions. For these files, it is also necessary to keep
> track of the 'description' entry in the stsc table. I guess that will
> require one more filed in the lqt_packet_index_entry_t struct,

That can be added.

> among
> other changes.

And these would be a LOT. In the worst case it means to change *all* stream
parameters (image size, codec, colormodel....) in the middle of the file.

> Kind regards,
> // Erik

Burkhard