Dolby TrueHD is it being over-hyped?

[GasCat]

I have a few questions:
What receivers are capable of using TrueHD?
What players are capable of using TrueHD?
Isn't this just another way for Dolby Labs to make money?
Isn't this something that was started with the HD-DVD camp because they don't have 50 GB to play around with?
Can someone give me the cons of using PCM?

I read this on Dolby's site:
"In the end, the sound quality will be essentially the same as that of audio decoded within the player as PCM signals and transported through a current-generation HDMI connection to the A/V receiver."
http://www.dolby.com/consumer/techno...HD_avrs_3.html

So now if I want this TrueHD I have to hope they will put that sound track on a disc, I have to use HDMI 1.3. I have to get a new reciever. I have to wait for a firmware update.
Why not stick to PCM and stuff this thing down the hole with HD-DVD when it finally dies?

Edit: Corrected HTML link.

[Blus Brother]

It may be a little more dynamic in sound - like I think DTS is compared to DD, but I doubt it will really sound that much better. Sort of like people that have 7.1 surround systems like me, but how many discs actually have 7.1 or even 6.1 surround on them. Only a few here and there - and 6.1 has been around for about 4 years or so.

[GTP]

Originally Posted by GasCat

I have a few questions:
What receivers are capable of using TrueHD?
What players are capable of using TrueHD?
Isn't this just another way for Dolby Labs to make money?
Isn't this something that was started with the HD-DVD camp because they don't have 50 GB to play around with?
Can someone give me the cons of using PCM?

I read this on Dolby's site:
"In the end, the sound quality will be essentially the same as that of audio decoded within the player as PCM signals and transported through a current-generation HDMI connection to the A/V receiver."
http://www.dolby.com/consumer/techno...HD_avrs_3.html

So now if I want this TrueHD I have to hope they will put that sound track on a disc, I have to use HDMI 1.3. I have to get a new reciever. I have to wait for a firmware update.
Why not stick to PCM and stuff this thing down the hole with HD-DVD when it finally dies?

I believe that you need a player with DD THD...and any hdmi receiver with 1.1 or better to get multi channel PCM from a DD THD track.
If you had the player with DD -THD and a 1.3 receiver...it still is output as PCM either way.

[hmurchison]

TrueHD is Dolby using Meridian Lossless Packet (MLP). DVD-Audio is based around the same codec.

TrueHD isn't worthless by any stretch. It's able to compress an audio file down to probably half the original size and maintain full fidelity.

On a 50GB disc with few audio tracks it likely means very little. But hopefully in the future there will be multiple audio tracks and that's where TrueHD pays dividends.

Even if we have huge amounts storage more efficient compression allows the producer to put in more data. It's a bonus when adding more doesn't harm the quality either.

[GasCat]

I think many people are under the impression that it will surpass PCM sound. Some are saying we need this on Blu-Ray movies when a PCM track will do the same thing. Others are saying they can't wait for it when the receivers they own will not even output TrueHD sound.

I know Dolby Labs from when they were using Dolby A and Dolby B. They keep adding compression technoligies to make extra revenue. Hardware manufacturers love it so they can sell new units. It's a win-win game for them but not necessarily for us the consumers.

I know that TrueHD is touted by the HD-DVD camp as a reason why you should buy their players. I am not saying it is useless, I am asking if this has been misunderstood and over-hyped.

I definitely have questions many of which haven't been answered. Thanks for the correction on HDMI 1.3. It's still fairly confusing.
I saw this and thought it meant HDMI 1.3 was required.

[Steeb]

Originally Posted by GasCat

I have a few questions:
What receivers are capable of using TrueHD?

Any receiver capable of receiving 5.1 PCM over analog or HDMI, assuming your player decodes DTHD.

Originally Posted by GasCat

What players are capable of using TrueHD?

The vast majority of the players sold: PS3, Panny (both versions), New Samsung (I think)... there may be more, I'm not sure.

Originally Posted by GasCat

Isn't this just another way for Dolby Labs to make money?

Um... no. It's a way for us to get losslessy compressed soundtracks.

Originally Posted by GasCat

Isn't this something that was started with the HD-DVD camp because they don't have 50 GB to play around with?

Um... no. DTHD is basically MLP (what was used in DVD-A) with some Dolby extras thrown in. Also, let's not forget that currently there are a ton of BD-25 discs out there, so 50GB is not guaranteed. Plus, eventually we could see BD titles with HD PiP (basically two 1080p HD streams to contend with,) which would make DTHD even more attractive.

Originally Posted by GasCat

Can someone give me the cons of using PCM?

1. It eats up space that could be used for other things (better PQ, extras, etc.)
2. It eats up bandwidth that could be used for other things (better PQ, extras, etc.)
3. It doesn't scale down like the advance codecs can (ie. if you only have 5.1 PCM and you use an optical connection, you only get 2.0 channels.)
4. It's easier to get better tracks (20/48 or 24/48 instead of 16/48) with an advanced audio codec, since PCM would take up way more space and bandwidth (like on Ghost Rider, where the DTHD track was 20/48 compared to the 16/48 PCM track.)
5. A BD-50 could have several DTHD tracks (for different languages) while they would never be able to get away with multiple PCM tracks (they might be able to squeeze in a second, but certainly not a third or fourth.) In fact, I think there's a BD title that's been announced that has two DTHD tracks - one in English and one in another language (Spanish?)

As for sound quality, assuming all other factors are equal (ie one track's not 16/48 while the other is 24/48,) uncompressed PCM = DTHD = DTS-HD MA.

Lossless audio codecs are the future - PCM is just a stop-gap measure. Better get used to it...

[ClaytonMG]

Which Blu-Ray players at this point don't decode Dolby TrueHD? The first Samsung doesn't, but are there any others?

[Steeb]

Originally Posted by ClaytonMG

Which Blu-Ray players at this point don't decode Dolby TrueHD? The first Samsung doesn't, but are there any others?

The first Pioneer doesn't either. I don't know about the Sharp player or the LG combo player.

Edit - I meant Philips, not Sharp. Thanks, dobyblue.

[dobyblue]

The Philips.

[ClaytonMG]

So the Philips and Samsung, right? I believe the first Pioneer had a firmware upgrade to decode it...

[cajmoyper]

Excellent explanation Steeb.

[Memnoch]

Onkyo 605 and 805 are supposed to process DolbyTrueHD. But this is kind of in debate. I have a PS3 that decodes it, then sends it via PCM to the receiver. I think that is how it works. So the 605 isn't really decoding anything. But supposedly, one of these days, there will be BD players that would send an undecoded source to the 605 to decode. I frankly don't give a shit how it works. My 605 sounds awesome and better than my last av receiver. NIN: BYIT BD is DolbyTrueHD and it sounds amazing on it. That's all that matters to me. All these nerds can argue back and forth until they are blue in the face about this crap. I did a lot of research on HDMI v1.3 before I bought any of my stuff and I feel I did the best I could with everything on the market at the time. Everything looks and sounds flawless, so I'm happy.

Samsung HL-T6189S
Onkyo 605
PS3
Wii

Damn skippy.

[coolwavepic]

For me I don't care what the sound is in as long as the SOUND DESIGN is excellent. I think that is the key right there.

I am all for DTS-HD and TrueHD but you have to have a good movie with sound design. Two that come to mind is Titan AE and The Others. Two movies I hope to come to Blu-ray.

[GasCat]

Is the sound coming from the current PCM tracks as good as the TrueHD tracks?

Can someone post some links to read more about Dolby TrueHD or is the Dolby site the simplest thing out there?

Why are these new Onkyo receivers which have TrueHD so highly acclamied if any receiver with HDMI will take the signal?

[dakota81]

No players pass TrueHD or DTS-HD to the receiver. The ones that decode TrueHD are Sony BDP-S1, Pioneer BDP-94HD, Panasonic DMP-BD10 & DMP-BD10A, PS3. The ones that decode DTS-HD-HR are the Panasonics. None decode DTS-HD-MA.

The cons of PCM is the space. PCM is usually 16bit/48khz, only on some new discs is 24bit/48khz. TrueHD is up to 24bit/96khz. Though I still think it's questionable if you can tell the difference between 48khz & 96khz. We can only hear up to ~20khz frequencies, so 40khz is all you need to capture the audio perfectly. Maybe 96khz helps the DAC?

Whatever the case with TrueHD, Warner is the only company that really likes it, and one of the reasons they prefer HD DVD is because there are more base features built into every player. When they advertise TrueHD on an HD DVD, everyone is guaranteed to be able to take advantage of it. Not so with Blu-ray.

[GasCat]

Thanks everyone who responded.

Just to clarify:
1. Getting a new receiver that has a TrueHD tag is not needed. Any type or receiver will do? Is a HDMI 1.1 connection required or...?

2. The sound signal is sent over to the receiver after it has been decoded by the player. If the player decodes the signal and sends it as an uncompressed PCM signal then you still have a bandwidth issue and you still have possible noise going through the wire. It uses less size on disc and that's about it. Is this all correct?

Last question:
What Blu-Ray movies have TrueHD right now? I read there were three. Thanks.

[HDJK]

Originally Posted by Steeb

5. A BD-50 could have several DTHD tracks (for different languages) while they would never be able to get away with multiple PCM tracks (they might be able to squeeze in a second, but certainly not a third or fourth.)

Well, actually they have: Identity

Originally Posted by Steeb

As for sound quality, assuming all other factors are equal (ie one track's not 16/48 while the other is 24/48,) uncompressed PCM = DTHD = DTS-HD MA.

Correct.

[HDJK]

Originally Posted by dakota81

We can only hear up to ~20khz frequencies, so 40khz is all you need to capture the audio perfectly. Maybe 96khz helps the DAC?

From Wikipedia:

'The Nyquist–Shannon sampling theorem states that perfect reconstruction of a signal is possible when the sampling frequency is greater than twice the maximum frequency of the signal being sampled,[2] or equivalently, that the Nyquist frequency (half the sample rate) exceeds the bandwidth of the signal being sampled. If lower sampling rates are used, the original signal's information may not be completely recoverable from the sampled signal.
For example, if a signal has a bandwidth of 100 Hz, to avoid aliasing the sampling frequency should be greater than 200 Hz.'

There is a huge discussion going on in the audio world about this. I won't go there again but there are people that think 192kHz is just good for marketing.

http://www.lavryengineering.com/docu...ing_Theory.pdf

[HDJK]

Originally Posted by GasCat

Thanks everyone who responded.

Just to clarify:
1. Getting a new receiver that has a TrueHD tag is not needed. Any type or receiver will do? Is a HDMI 1.1 connection required or...?

Yes, you need HDMI. HDMI 1.1 is limited to 5.1 in 24/96kHz. 1.3 goes all the way up to 24/192kHz, but I highly doubt we will see a movie with that sampling rate. Maybe if BD Audio starts to show up...

Originally Posted by GasCat

2. The sound signal is sent over to the receiver after it has been decoded by the player. If the player decodes the signal and sends it as an uncompressed PCM signal then you still have a bandwidth issue and you still have possible noise going through the wire. It uses less size on disc and that's about it. Is this all correct?

PCM is digital audio. The TrueHD bitstream is digital. With a bad cable and heavy interferencies there could be jitter introduced into the signal, which would be audible in the high frequncies. But under normal circumstances you will be fine. Most loudspeakers in use wouldn't show this error anyway.

Originally Posted by GasCat

Last question:
What Blu-Ray movies have TrueHD right now? I read there were three. Thanks.

AFAIK

- Legends of Jazz
- Ghost Rider
- NIN
- Letters from Iwo Jima
- Stomp The Yard

[GasCat]

Thanks HDJK. I think I have it down now.

Something occurred to me, TrueHD is mostly needed for M$'s VOD and HD-DVD due to bandwidth and limitations on diskspace. I find this fairly amusing.