Quote:
Originally Posted by Chris Moseley  Hi
Many members on this forum refer incorrectly to MPCM over HDMI as LPCM, which leads to confusion.
Regards
Chris Moseley
Yamaha UK |
Hello Chris,
Linear Pulse-code Modulation is the de-facto and long-established technique used for A-to-D conversion of audio signals and refers to the quantization of the amplitude being "linear". This technique is used in CDs, DVDs, WAV files etc. and has no bearing on what the sampling frequency is; or what the bit depth is; or how many channels are encoded with the technique. The term can, and is, correctly used to describe the formats employing this technique, including multi-channel LPCM.
The more generic term, PCM is often used to describe data encoded as LPCM - but not all PCM data is quantised linearly.
Consequently, all of the standards, including BD and HDMI, clearly and precisely refer to LPCM (aka L-PCM and linear PCM), even when referring to multi-channel LPCM.
Do a search on this HDMI document to see what I mean...
The only relevant place I've come across this term "MPCM" is from Yamaha - introduced, I suspect, by one of your marketing departments to help differentiate multi-channel LPCM from the 2-channel LPCM used on DVDs etc. However, this is a brand new acronym, and imho, it is more likely to confuse, as LPCM is well established, precise and understood e.g.
Wikipedia, or even
DTS. The members of the forum who refer to LPCM are doing so quite correctly.
Big smiles,
Andy.