linear pcm or dolby digital?? - Canadian TV, Computing and Home Theatre Forums

italfrank · 2007-03-24, 03:04 PM

Hello,
I was just watching the prestiege on my ps3 (blu ray of course) and saw that along with a 5.1 DD track they had a 5.1 uncompressed audio track. Here is my question. The 5.1 DD track read at 640 kbps 5.1. Then I switched my settings to linear PCM and tried using the uncompressed 5.1 signal, which, of course only gave me Pro Logic 2.0 but the reading was 6.9 mbps. Logically, which would be better? The 2.0 pro logic track at 5.9 mbps or the 5.1 dd track at 640kbps?

Thanks for any suggestions

calvin940 · 2007-03-24, 03:42 PM

Pretend you have two identical streams. Let's say that one is compressed and the other is not. Logic dictates that the data rate for the uncompressed would need to be much faster to transfer the same audio data in the same time frame as the compressed audio. They are identical streams but the bandwidth needed is different.

Now take your case. Even though the uncompressed stream is DPL 2.0, it still needs a higher transfer rate to transfer audio information since it is not compressed (whereas your DD 5.1 is compressed and needs a lower transfer rate for the audio).

The transfer rate in this situation does not dictate the quality of the audio, just how much information it needs to transfer per second.

Cal

Hydroaxe · 2007-03-24, 04:35 PM

Why did you only get 2.0 out of the 5.1 uncompressed audio track?

italfrank · 2007-03-24, 10:24 PM

cuz i am not using hdmi

maddog40 · 2007-03-25, 03:53 AM

Then I would go DD5.1, the other is only 2 tracks, you will loose all effects. In HDMI though there is an outstanding difference between uncompressed 5.1 and DD05.1, enough to warrant changing avr.

Ham.Clan · 2007-03-25, 11:12 AM

"In HDMI though there is an outstanding difference between uncompressed 5.1 and DD05.1, enough to warrant changing avr."

Really? I've wondered about this.
Does the HDMI signal have to be processed by the AVR in order to get 5.1 uncompressed?
My AVR doesn't have the HDMI connection, therefore the HDMI goes from PS3 directly to the tv and then TOSlink optical out from PS3 to AVR.
I get the same 2.0 on uncompressed 5.1 as italfrank with this set-up.
Should I be using the TOSlink optical out from the tv to the AVR?
My apologies if I hijacked this thread. Please delete if so.

Ham.Clan

2007-03-24, 03:04 PM	#1
italfrank Join Date: Sep 2005 Location: Toronto Posts: 105	linear pcm or dolby digital?? Hello, I was just watching the prestiege on my ps3 (blu ray of course) and saw that along with a 5.1 DD track they had a 5.1 uncompressed audio track. Here is my question. The 5.1 DD track read at 640 kbps 5.1. Then I switched my settings to linear PCM and tried using the uncompressed 5.1 signal, which, of course only gave me Pro Logic 2.0 but the reading was 6.9 mbps. Logically, which would be better? The 2.0 pro logic track at 5.9 mbps or the 5.1 dd track at 640kbps? Thanks for any suggestions __________________ For an interesting read if your bored

2007-03-24, 04:35 PM	#3
Hydroaxe Join Date: Nov 2006 Posts: 97	Why did you only get 2.0 out of the 5.1 uncompressed audio track? __________________ www.thislinkdoesn'twork.com

2007-03-24, 10:24 PM	#4
italfrank Join Date: Sep 2005 Location: Toronto Posts: 105	cuz i am not using hdmi __________________ For an interesting read if your bored

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2007-03-24, 03:42 PM	#2
calvin940 Veteran Join Date: Apr 2006 Location: Halifax, Nova Scotia Posts: 1,600	Pretend you have two identical streams. Let's say that one is compressed and the other is not. Logic dictates that the data rate for the uncompressed would need to be much faster to transfer the same audio data in the same time frame as the compressed audio. They are identical streams but the bandwidth needed is different. Now take your case. Even though the uncompressed stream is DPL 2.0, it still needs a higher transfer rate to transfer audio information since it is not compressed (whereas your DD 5.1 is compressed and needs a lower transfer rate for the audio). The transfer rate in this situation does not dictate the quality of the audio, just how much information it needs to transfer per second. Cal

2007-03-25, 03:53 AM	#5
maddog40 Join Date: Dec 2006 Location: Montreal Posts: 300	Then I would go DD5.1, the other is only 2 tracks, you will loose all effects. In HDMI though there is an outstanding difference between uncompressed 5.1 and DD05.1, enough to warrant changing avr.

2007-03-25, 11:12 AM	#6
Ham.Clan Join Date: Aug 2006 Location: The Highlands Posts: 773	"In HDMI though there is an outstanding difference between uncompressed 5.1 and DD05.1, enough to warrant changing avr." Really? I've wondered about this. Does the HDMI signal have to be processed by the AVR in order to get 5.1 uncompressed? My AVR doesn't have the HDMI connection, therefore the HDMI goes from PS3 directly to the tv and then TOSlink optical out from PS3 to AVR. I get the same 2.0 on uncompressed 5.1 as italfrank with this set-up. Should I be using the TOSlink optical out from the tv to the AVR? My apologies if I hijacked this thread. Please delete if so. Ham.Clan