Originally Posted by Ross Ridge No, this is completely wrong.
All games on both the Xbox 360 and the PlayStation 3 support PCM as this is the format all games generate internally. If you force these consoles to use Dobly Digital instead then there will be a loss of audio quality when the PCM data is lossy compressed into Dolby Digital.
Never ever use Dolby Digital over HDMI unless you're given no alternative. Both mulitchannel PCM and the lossless DTS HD and Dolby TrueHD formats are superior to Dolby Digtal as the carry sound with no loss of audio quality.
No.. that is completely wrong.
Ross.. I dusted off my game console audio notes (yes I keep links, notes, old posts, etc, for just this reason. these conversations keep coming up, and I'm not getting any younger.
Any game made for the 360 is required
to support DD 5.1.
More importantly, however, the Xbox 360 doe not support more than 2 channel PCM, regardless of SPDIF or HDMI...http://support.microsoft.com/kb/906660
Supported audio formats
The Xbox 360 console supports the following analog and digital audio formats:
Digital Stereo PCM, 16-bit, 48 kilohertz (kHz)
Dolby Digital® 5.1 channel digital audio, 48kHz
Playback of DTS (Digital Theatre Surround) 5.1 media (such as movies) by passing the encoded DTS digital bitstream to an external DTS decoder
My understanding on the PS3 is that the PCM output is decoded Dolby Digital or DTS depending on how it is encoded for 95% of the titles released (see my PCM caveat below)..
I think all the Sony in house "published" titles are 5.1 or 7.1 PCM, as are a couple of premiere developers... (I remember that "Resistance" had a PCM option, as did "Uncharted 2..") otherwise, it's DD or DTS.
Why would there be an audio selection menu in game to pick your output on those titles (i.e. to your comment that they are all LPCM?)
My understanding is if you have the PS3 sending PCM on most titles, it is decoding the DD and outputting as 5.1, not the engine output pre encoder..
A friend of mine spent the last 10 years as the head of audio for EA Black Box... I'll get some more clarification...
I stand by my comment... DD is the way to go for the 360.. bitstream or PCM on the PS3 should get you the same audio quality as well for most games (unless they have PCM as an option.)
I also looked back an one of my comments I posted, after re-reading it, and knowing what I wanted to say, is erroneous..
PCM is not the internal audio format used in games.. of course all of the audio starts off as PCM (it's the foundation of digital recording), and which was my point, but must be compressed (I believe that the Xbox uses a proprietary format called XNA) to be used in the engines.. neither console has the space (either on disc or RAM,) bandwidth or headroom to handle 256 channels of PCM in real time, mix it, add reverbs, etc.....