5.1/7.1 PCM, HDMI, and DSP - An Explaination of the Future-Proof receiver - Page 6

To supplement what has already been described earlier, I thought there might be some interest in a recent article by Rodolfo La Maestra, the Senior Technical Director at HDTV Magazine entitled "HDMI Part 5 - Audio in HDMI Versions." The link is http://www.hdtvmagazine.com/articles...i_versions.php

Dana

So, can I conclude the following from this:

1. If you have a receiver with no HDMI input but with a 7.1 input and a hd-dvd player/BR-player with an internal DD+ and TrueHD decoder, it is possible to get DD+ and TrueHD by connecting the Player via 8 analog outputs. (2xfront,4xrear,1xcenter and 1xsub).
2. If you have a receiver with HDMI input (almost all receicers that are now on the market) and a hd-dvd player/BR-player with an internal DD+ and TrueHD decoder than you ALWAYS can get DD+ and TrueHD by connecting the player via a HDMI cable to the receiver.

IF my 2 points are correct, than I don't get the whole picture:
When we take point 2. we see that the signal from the player is going DIGITAL (via HDMI) to the receiver. How is this possible? The player has done the decoding so I assume that the signal is analog than?
If we look at point 1. of me you see that the signal goes from digital to analog in the HD-player (that does the decoding) and than goes through 8 analog cables to my receiver. Than my receiver does NOTHING with this signal but only amplify it and output it to my speakers.

So, 1. makes sense to me but 2. not.

Can someone correct my story cause obviously I still not see it........ (shame,shame)

greetings and again sorry for the English.

Sander........

Correct. Couple of very minor points:

The receiver isn't really getting DD+ or TrueHD, it's just receiving an analogue signal. It has no idea where the analogue signal came from or what it was before.

Also, instead of labeling the 8-channel analogue connections as 4xRear, it's more accurate to think of it as 2xSide and 2xRear.

8-channel analogue inputs are still the rarity. Most of the time you'll see 6-channel (5.1) analogue connections on players and receivers.
Out of all the receivers on the market, very few have HDMI connections. Also, the receiver isn't really getting DD+ or TrueHD via HDMI, it's just receiving a linear PCM signal. I has no idea what the PCM signal was previously.
Decoding means that the compressed signal is unpacked or uncompressed (to PCM), like unzipping a file. It has nothing to do with conversion to analogue. D-to-A conversion is a completely separate step. The signal being sent via HDMI is still 100% digital.
Not to worry; your English is perfect.

Best,
Sanjay

so can I make the final conclusion that if I buy a high end (high quality) HD-DVD/BR player in the future that has internal decoding and a 7.1 output and connect it to my high end Denon A1-SR receiver to the 7.1 input, I get the same result as someone that buys a new receiver next year with HDMI 1.3 and al capable internal decoders for the new audio standards DD+, TrueHD and DTS-HD?

I think with that bit Sanjay was referring to the 7.1 analogue inputs

As SiriuslyCold mentioned, I was replying to Sander's question about "a receiver with no HDMI input but with a 7.1 input". My post may have been confusing since it switches over to discussing HMDI inputs.
Discussion about codecs can get confusing, so the convention is to refer to lossy encoding as "compression" and lossless encoding as "packing". To that end, LPCM is used to differentiate from PPCM (packed PCM) like MLP, TrueHD, DTS HD MA, etc.

Sanjay

You'll get the same results as far as sound quality of the decoded signal.

The disadvantage is that the 7.1 analogue inputs on most receivers cannot be digitized to apply bass management and time alignment. So you will have to apply crossovers and speaker distance delays in the player. These features are ususally not as thorough in players as they are in receivers.

Also, receivers have features that are not found in players (surround processing, room correction/EQ, etc).

While you can use the analogue outputs of the player, you'd get better results with a receiver that has HDMI (1.1 or 1.2 or 1.3).

Sanjay

I always thought that linear in LPCM meant that the relationship between the signal amplitude and the PCM value for a given sample were linearly proportional. Alternatively, you can have nonlinear relationships where, for example, the amplitude resolution at low levels might be coarser than at high levels. Is this not true?

Ed

Maybe it is. But I've always seen LPCM used as a differentiator from PPCM, signifying that it isn't compressed or packed.

Sanjay

moreover, it's much simpler and cheaper to hook up an HDMI cable vs 6-8 analog cables. and if you decide to have both blu-ray and hd-dvd players then it will be even more inconvenient because only a couple receivers/processors have more than one 7.1-analog input.

Panasonic's definition here http://panasonic.co.jp/pavc/global/b...ary/index.html is:

"Linear PCM
"This is an audio recording format that does not use digital compression. It allows you to record and play high-quality sound without the loss that occurs from encoding and decoding. Linear PCM enables high-bit, high-frequency 44.1-kHz/16-bit sampling for CDs and 192-kHz/24-bit sampling for DVD-Audio."

Dana

Thanks for your effort but this doesn't help at all. In their definition, when they say "doesn't use compression", I'm pretty sure that they mean lossy compression. So they are merely trying to explain PCM and make no comment about the "linear" term.

I ran this by a colleague and he too understood linear as I had described.

Ed

I would like to clarify that the reason I a looking for a reciever that accept 7.1ch LPCM over HDMI is because my main HD player will be a PLAYSTATION 3 and some of the announced software (Lair and Resistance PS3 games and Final Fantasy Advent Children and Ghost In The Shell 2 Blu-ray films) supports 7.1ch uncompressed LPCM...

I want HDMI support for this because that is the way 7.1ch LPCM is output from PS3


It seems the HK 645 can do 5.1ch LPCM at least (thanks M code) but I still dont have my answer on 7.1

yes I too am wondering about this. would be a good option if it does 7.1. If doesnt then is there another HK AVR on way that can ?

The Panasonic XR700 will meet your needs. http://panasonic.co.jp/pavc/global/b...onvenient.html

"8ch Linear PCM Input through HDMI

"The DMP-BD10 decodes the Dolby® Digital Plus format's 7.1-channel surround sound signals, converts them to linear PCM, and outputs them through an HDMI terminal. The SA-XR700 receives these signals through its HDMI terminal and digitally amplifies them to produce a dynamic 7.1-channel surround sound. Only HDMI-compatible products can unlock the full digital surround sound potential made possible by the huge amount of audio data on a Blu-ray disc."

Dana

Given that there aren't any sources that can ouput 7.1 via HDMI right now (at least that I'm aware of) I'm not sure how anyone can confirm this.

why do I get better results with HDMI on my receiver? Isn t it so that the decoding is done in the player and that than, just like with anolog outputs, the only thing a receiver can do is amplify?

You also say that 7.1 inputs on MOST receivers cannot be digitized. How can I find out if my receiver can do this? (I have an, I think, very advanced receiver)

My receiver has two 7.1 inputs so that shouldt be a problem

Isn t it so that u use the DAC s in the player if you have 7.1 input but also with a HDMI (1.1) input?
Maybe I m still missing something but isn t the DAC the process where the decoding of the DD+/TrueHD is done?

What one do you have?

No, because you're not converting it to Analog in the player. The audio transmitted by HDMI is digital.

By "results" I meant the overall sound. Whether done in the player or receiver, the decoding itself will be the same (decoding = decompressing or unpacking the data). However, decoding is just one part of what makes up the overall sound you hear.

Receivers do more than just amplify the signal. They can do bass management, time alignment, surround processing, room correction. Each one of these contributes to the final sound that reaches your ears. Some of these, like bass management and time alignment, can be set on the player (though receivers usually have finer settings). But surround processing (which converts 5.1 to 7.1) or room correction (which minimizes the room's unwanted contributions to the sound) isn't found on players.

In order to take advantage of these features, you need to have the signal in digital form in the receiver. This is where HDMI is useful, since it can transmit the signal digitally instead of in analogue form. This will help improve the sound that eventually reaches your ears; i.e., better results.
DACs are Digital to Analogue Converters, and they do what the name implies. The decoding process takes place much earlier.

Soundtrack are encoded for storage and transmission, using lossy compression or lossless packing. During playback, the first thing that has to be done is decoding of the signal (decompressing or unpacking the bitstream) in order to get the original soundtrack back in its original form (PCM). The same thing has always happened with regular DD and DTS signals.

Once in PCM form, you can manipulate the signal any way you want. This is when your receiver applies all its features. Only after this step are the DACs used to convert the digital signal to analogue, just before the amplification step.
It may not be a problem, but using HDMI will provide better results (see above) and reduce cable clutter. If you connected Blu-ray and HD DVD players to your receiver using only analogue connections (8 audio and 3 component video for each player), then that would mean 22 cables total. As menmoch mentioned, wouldn't it be cheaper and easier for you to use just one cable for each player?

Sanjay

Going back to your original question, I wouldn't be bothered about future-proof thingies if I had your Denon top-of-the-line receiver. I understand HDMI connection has advantages. But what's wrong with a bunch of analog cables if you don't care?
BTW, I heard that the Denon has ADC on 7.1ch analog input. So I think (may be wrong) you can still apply room correction, BM, TA, and other DSPs to the signal. I know additional ADC and DAC may degrade SQ, but I heard that the Denon's ADC is as good as to be virtually transparent. Again, I'd enjoy the Denon for a long, long time.

The PS3 just launched in Japan today and Resistance:Fall of Man is one of the launch games available there.....the Japanese version is just like the North American version in that there is an option for 7.1ch LPCM audio output (which is in-game,BTW, not just in cinema FMVs)

In his review of the Samsung BD-P1000 blu-ray player, Kris Deering offers this comment on HDMI for audio. The link is http://www.hometheaterhifi.com/volum...06-part-2.html

"Consumers who have the capability to use HDMI for their audio and have gear that is 1.1 compliant (see your product's owner's manual for information) should use this connection for all of their needs. This will allow you to take advantage of the uncompressed PCM soundtracks found in most of the movies. The analog multi-channel outputs also support this soundtrack but they lack the ability to do time alignment and channel level balancing. The only option available is bass management. This is a HUGE oversight by Samsung. Proper channel balancing and time alignment are CRUCIAL for proper playback of multi-channel sound. Not only can you create phase issues due to distance differences between channels to the main listener, but channel levels can be grossly different and completely destroy the intended mix in regards to soundstage. Again, if your receiver or processor allows for audio via HDMI, I highly recommend sticking with that. If you have to use analog, I recommend receivers or SSPs that allow for analog-to-digital conversion so proper time alignment and channel balancing can be achieved."

Dana

If you're buying things like blu-ray players, or high-end DVD, I don't even understand why they even still bother doing analog circuits.

I'd love to see a Denon 3910 for example, at reduced price, without all the analog stuff. Make it a transport, it's meant to be used with digital gear anyway.

It's like sticking DOS support in Vista... :-)

Ok, this may be a dumb question.

I have been holding out on a new receiver until the addition of HDMI 1.3 I have a 1080p 1.3 compatible set, and have the Toshiba XA-2 on preorder from ****************.

Since it looks as if receivers that are already out can pass true 7.1 uncompressed PCM audio (TrueHD etc...) via 1.1 and 1.2, is it pointless waiting for a 1.3 receiver? My only problem is that if my output of the HDDVD player is 1.3, the receiver is 1.1/1.2, does that mean I'm only getting 1.1/1.2 back to my TV set? Or is there HDMI video passthrough on the receivers to allow the 1.3 standard to pass? I know there is a new video standard that is allowed with 1.3, and that is why I was waiting for it. Not to mention, I would love to enjoy true 1080p resolution. Thoughts anyone?