I think I am starting to grok the audio thing, but not quite yet. We have been trying really hard to figure out what it doesn't do, but I think it may make more sense to understand what it does do, and why.
As I update the FAQ, I keep seeing patterns in what does and does not work, and I've felt like we are all just blind men feeling little parts of the proverbial elephant.
I think we are definitely dealing with a minimal audio firmware subsystem, designed to hit minimum required specs and to be as stable as possible for an early market timing driven release (limited xmas 07). It may be that they pulled back on the feature set because it was not stable enough to release all the additional codecs, and so therefore, we are getting what follows:
(reference this page for where I am getting some requirements for this stuff... http://en.wikipedia.org/wiki/Compari...hnical_details
- do the bare minimum to get out the union of required audio formats for HD and BD in a multichannel way, this means:
- Dolby Digital 5.1 only (no EX)
- DTS core (5.1)
- LPCM 5.1 and better
- Dolby True HD, bare minimum requirement is 2 channel
- Speaker setup is really the absolute minimum - the number of channels, and crossover to prevent damage to band-limited speakers.
On board decoding for streaming as LPCM on HDMI:
- much the same as analog decoding. Do the same bare minimums as above to pass out over HDMI.
- on board decoding for analog and digital LPCM passing on HDMI are really the same thing. It is really just where the resulting bitstream gets sent to, I2S outputs or HDMI transceiver
- Since the heavy lifting is the on-board decoding, all mandatory codecs get passed on HDMI. This is not a stretch of the imagination, since decoding them means pulling them out of the transport streams. If you've pulled them out to decode, then it's easy enough to shovel that same data to the HDMI inteface for external decoding.
- anything that isn't getting touched for onboard decoding is also not getting passed on bitstream, since it is not already getting pulled out of the transport streams.
I know if I were dealing with the this, and needed to get the product out for whatever market reasons, and there were issues with the stability, I'd pull everybody into a room and make sure we could get the HD and BD mandatory specs, and get them completely stable. As we have seen with the motorboating, even core stability is not quite there.
I'm not making comment on whether or not this is ok (this has been discussed at other times), but just trying to see the whole elephant, if you pardon the metaphor.