[ogg-dev] OggPCM2 : chunked vs interleaved data

Erik de Castro Lopo mle+xiph at mega-nerd.com
Tue Nov 15 15:49:28 PST 2005

Sampo Syreeni wrote:

> Secondly, I'd like to see the channel map fleshed out in more detail. 

Sampo, I'm the one who came up with the channel mapping this.

Let me flesh it out a bit more this evening.

> (As a further idea prompted by ambisonic compatibility encodings, I'd 
> also like to explore the possibility of multiple tagging. For example, 
> Dolby Surround, Circle Surround, Logic 7 and ambisonic BHJ are all 
> designed to be stereo compatible so that a legacy decoder can play them 
> as-is. But if they are tagged as something besides normal stereo, such a 
> decoder will probably just ignore them. So, there's a case to be made 
> for overlapping, preferential tags, one telling the decoder that the 
> data *can* be played as stereo, another one telling that it *should* be 
> interpreted as, say, BHJ, and so on. Object minded folks can think of 
> this as type inheritance of a kind. But of course this is more 
> food-for-thought than must-have-feature since nobody else is doing 
> anything of the sort at the moment.)

Doesn't the Channel Conversion Header fulfil this need? Maybe
it needs a bit more explanation and an example.

> > Anyone wants to speak in support of chunked PCM?
> Actually I'd like to add a general point against it.

Thanks for speaking up. Opinion noted.

  Erik de Castro Lopo
A Microsoft Certified System Engineer is to computing what a
MacDonalds Certified Food Specialist is to fine cuisine.

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