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PCM 5.1 question

post #1 of 19
Thread Starter 
Some blu-ray discs say PCM 5.1 while other say UNCOMPRESSED PCM 5.1...Are they the same?
post #2 of 19
Quote:
Originally Posted by sdrph View Post

Some blu-ray discs say PCM 5.1 while other say UNCOMPRESSED PCM 5.1...Are they the same?

Yes, exactly the same:

5.1 Uncompressed =
5.1 PCM =
5.1 LPCM =
5.1 Uncompressed PCM
post #3 of 19
I second that.
post #4 of 19
will your DD 5.1 be uncompressed if you use HDMI and have loseless sound?
post #5 of 19
Quote:
Originally Posted by MattS90 View Post

will your DD 5.1 be uncompressed if you use HDMI and have loseless sound?

DD stands for Dolby Digital and is compressed and lossy format. While it is uncompressed after decoding it is still lossy. Dolby TrueHD is compressed lossless format (as is DTS HD Master) and is lossless LPCM after uncompromising.
post #6 of 19
Quote:
Originally Posted by William View Post

... and is lossless LPCM after uncompromising.

im sure thats a typo, but its funny nonetheless


a note - If your player decodes Dolby Digital, what gets on the HDMI is also PCM, except that it is derived from a lossy source (as opposed to PCM derived from a lossless source)

if you are familiar with WAVs, FLACs and MP3s - think of it this way; the computer can only play PCM (WAV format)

so if you have an MP3, it will have to be decoded to WAV to play - the WAV is uncompressed, but it is sourced from a lossy MP3
post #7 of 19
Quote:
Originally Posted by SiriuslyCold View Post

im sure thats a typo, but its funny nonetheless ...

....but LPCM is uncompromising. Oh well I guess I should read before I post.
post #8 of 19
i think i get it lol
post #9 of 19
so i still need truHD for fully uncompressed ...from uncompressed source thru uncompressed hdmi audio to receiver that decodes the uncompressed truHD
post #10 of 19
Quote:
Originally Posted by MattS90 View Post

so i still need truHD for fully uncompressed ...from uncompressed source thru uncompressed hdmi audio to receiver that decodes the uncompressed truHD

You seem to be confusing compressed with lossy (which many do). They are two different terms. Compressed means that the data stream is reduced from the origanal LPCM. Lossy is perceptually coded and has music information thrown out and missing. Lossy is always compressed but compressed is not always lossy. DD is always lossy/compressed, TrueHD is lossless/compressed, and LPCM is lossless/uncompressed. Once TrueHD is decoded it goes from lossless/compressed to LCPM lossless/uncompressed.
post #11 of 19
i think my denon 1908 reciever does LPCM or maybe just PCM im not sure but i KNOW it doesnt do any TrueHD ... so what would be my best option?
post #12 of 19
Quote:
Originally Posted by MattS90 View Post

i think my denon 1908 reciever does LPCM or maybe just PCM im not sure but i KNOW it doesnt do any TrueHD ... so what would be my best option?

LPCM = (L)PCM (Liner) Pulse Code Modulation

Hook up your BD/HD DVD player by HDMI and set the player to decoded TrueHD and putput LPCM. You can chose LPCM or TrueHD from the audio menu and they will be same (all other things being equal).
post #13 of 19
but my receiver doesnt decode TrueHD
post #14 of 19
Quote:
Originally Posted by MattS90 View Post

but my receiver doesnt decode TrueHD

Your receiver doesn't need to decode TrueHD, the player does it. Your receiver just gets LPCM audio from the player.

shinksma
post #15 of 19
Sorry for my ignorance but I'm still not sure I understand.

DTS -MA and DD HD usually sound great. If the disc says PCM 5.1, does that mean there was no loss at any point?
post #16 of 19
if the disc says PCM, Dolby TrueHD or DTS Master Audio there is no loss.
post #17 of 19
Quote:
Originally Posted by shinksma View Post

Your receiver doesn't need to decode TrueHD, the player does it. Your receiver just gets LPCM audio from the player.

shinksma

THATS AWESOME ty!
post #18 of 19
Quote:
Originally Posted by shinksma
Your receiver doesn't need to decode TrueHD, the player does it. Your receiver just gets LPCM audio from the player.

shinksma



Does that only apply to HDMI or can a optical digital cable be used?

I have a playstation 3 that decodes True HD but my receiver is not HDMI compatible
post #19 of 19
Quote:
Originally Posted by mmountainbiker View Post

Does that only apply to HDMI or can a optical digital cable be used?

I have a playstation 3 that decodes True HD but my receiver is not HDMI compatible

Unfortunately, no. Toslink is limited to 2 channels of PCM. It takes HDMI to get multichannel PCM. The PS3 is not a good match for those us with older AVRs lacking HDMI.
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