Originally Posted by bhoier
I understand that I can choose from the BD movie menu, but how do I know I'm not getting a down-sampled soundtrack (doesn't it sometimes just revert to reg. DD or DTS?)?
If my screen just shows EXT. In how can I tell what it's deciphering? I put Hellboy at 5.1 PCM instead of the alternative (DD) and it played fine...so is PCM ONLY hi-def, and since I heard something it WAS hi def. sound?
PCM is the uncompressed digital format. All the various protocols (DD, DTS, DD+, trueHD etc) are compressed versions of the PCM. The player first decodes the protocol to PCM. If you are using the 5.1 PCM track on the disk, it doesn't need to decode it, because it is not encoded. When you use the analog out, that is no longer digital, so the PCM is converted to analog via the DACs in the player. That's why they calll it analog out.
The conversion to analog has to happen before the speakers, usually before the amplifier. If you use HDMI, the conversion to analog happens in your receiver. Even when you use the legacy digital connection (optical, digital coax) it still converts to analog in the receiver, but you can't send the hi-res formats over the legacy connections.
In short, the answer to your last question is yes. Had you chosen the DD track, it would first be decoded to PCM, and then converted to analog in the player, then sent through the analog out to the receiver. The same is true if you choose DD+, or true HD.