[FFmpeg-devel] [RFC] additinal desc_type for dtshd mpeg-ts demuxer

[Måns Rullgård]

Nico Sabbi <Nicola.Sabbi at poste.it> writes:

> On Monday 09 June 2008 09:48:34 M?ns Rullg?rd wrote:
>> "Ian Caulfield" <ian.caulfield at gmail.com> writes:
>> > 2008/6/9 Andreas ?man <andreas at olebyn.nu>:
>> >> M?ns Rullg?rd wrote:
>> >>> Is it correct to use the same codec id?  Can AC3/DTS decoders
>> >>> in general handle all the variants?  Might an lavf-using app
>> >>> want to distinguish between them?
>> >>
>> >> IEC958 (SPDIF) comes to mind.
>> >> You might want to configure AC3, DTS, etc to be sent directly to
>> >> a AV receiver, but such receiver might not be able to decode DTS
>> >> HD and such, so it is necessary to be able to distinguish
>> >> between the variants.
>> >>
>> >> Ether we could add more codec IDs or use sub_id. Dunno what's
>> >> best though.
>> >
>> > I think DTS is meant to fallback nicely - a decoder that can
>> > handle DTS but not DTS-HD should be able to decode a DTS-HD
>> > stream as just 1.5mbs DTS and ignore the extra data... not sure
>> > if that's true in practice though!
>>
>> However that may be, it still means losing data.  In such a
>> situation I'd want to use a software decoder for DTS-HD streams.
>
> IMO a different stream type requires a different codec_id/decoder pair

The question is when to call it different stream types, rather than
variants of the same type.  We don't differentiate (much) between MPEG
audio layers, for instance.

-- 
M?ns Rullg?rd
mans at mansr.com