[Matroska-devel] Re: Profiles v2

Steve Lhomme steve.lhomme at free.fr
Mon Mar 14 21:19:25 CET 2005


And thanks for commenting :)

Zen a écrit :
> Steve Lhomme wrote:
>> Hi,
>> I just uploaded a draft of hardware profiles that we could use. Any 
>> comments are welcome, because it's an important part if manufacturers 
>> consider using Matroska.
> DTS : should be able to handle 6.1 or 7.1 streams. 7.1 audio is the 
> future of audio, even more in computers (see HDA, Intel High Definition 
> Audio in relpacement of old AC97)

The number of supported channels is an indication for the player. 
Meaning that it should be the minimum to support. Same for the codec 
list. They will probably all support WMA and WMV9. But we don't had that 
to our list, simply because we don't support these codecs for the moment.

> Resolution : specify this is "up to" : what to do of video in 712*572? 
> Should it be OK with players supporting 720*576? Video should be PAL 
> (720*576) or NTSC (720*480) with no ratio problems

I used PAL as an example. Of course it's not a strict limit. And the 
main pb on resolution is the one for PocketPCs as most of them don't 
support VGA, maybe even some PMP ones don't. So the choice here (and 
everywhere else too) is do we want very few but very good profile 
compliance, or a more relax one that could be used in lots of devices.

I'm undecided on this. And that will probably be a team decision 
(Christian ? Betaboy ? Mosu ? Haali ? Toff ? etc).

> Are you sure that TTA, WavPack and Flac are necessary? This is not a 
> mass usage... a lot less than DTS 6.1!!! Will it be used by Industry? I 
> think not, Industry think to lossly compression...

Support for these codec is easy. But it's true that it looks strange 
that we support 3 lossless codec. Especially since some devices would 
not be compliant just because of that. Maybe I consider them as too 
important. If I had to choose one, it would be Wavpack, because it has 
this hybrid mode, which is good for portable players. So maybe I'll drop 
the other 2. Having at least one (again, that list in the minimum) is 
also a choice of quality vs ease of compliance... In the other hand TTA 
is a CoreCodec project and the format itself is very simple and 
efficient compared to FLAC. But that would be more a political choice.

> "DVD Recorders" : name is bad : why not HD player?

True. I thought about that afterward, but H was already taken (and D 
too). I'll rename the "HD player" ID to something else and use H for the 
HD profile.

robUx4 on blog <http://robux4.blogspot.com/>

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