What is the highest quality Audio format for HD movies

[cmdrdredd]

Wondering which format is higher quality. So far I know of Uncompressed PCM, Dolby TrueHD, and DTS-HD Master Audio.

I know TrueHD is more widely used. I know that DTS-HD: MA is rarely used.

I see that spiderman 3 on Blu-Ray has Uncompressed PCM 5.1 and TrueHD. If TrueHD is lossless then what is the benefit(if any) to use Uncompressed PCM?

 

[zinfamous]

the benefit is watching inocuous digital readouts on your $50,000 audio processing equipment show micro differences in the sound output. Your ears will never know, however.

Best I understand, however, is that Master is the highest quality, technically (I liken it to RAW image files). PCM and TrueHD are interchangable, I think, with TrueHD maybe having a slight advantage. The only tangible benefit to these formats over DTS/DD+ is the ability to go "true" 7.1. Of course, I could be talking out of my ass, so best to wait for someone who knows what they're talking about

 

[jpeyton]

Uncompressed PCM/Dolby TrueHD/DTS-HD MA are all equal in their native forms; they are all lossless.

Blu-Ray titles tend to have more uncompressed PCM soundtracks because of their additional space. Dolby TrueHD is a form of lossless compression that is more popular on HD DVD (for two reasons; 1) HD DVD players have TrueHD decoding built-in and 2) conserve space on 30GB HD DVD discs). DTS-HD MA is a form of lossless compression, but there are fewer players/receivers with decoders for it.

 

[cmdrdredd]

So Uncompressed PCM and TrueHD are the same bitrate etc?

 

[superbooga]

Most of the earlier BD players didn't support TrueHD. Now that they do, studios like Sony are phasing out support for uncompressed PCM on their releases.

 

[cmdrdredd]

Originally posted by: superbooga
Most of the earlier BD players didn't support TrueHD. Now that they do, studios like Sony are phasing out support for uncompressed PCM on their releases.

I see, well I was wondering if there was any quality difference. Guess not.

 

[CMC79]

What exactly do you need to have in order to hear these soundtracks? I have a PS3 and an HD-A2/360 add-on (I know the add-on is never going to have it). My current receiver is DD/DTS only; I've seen only a few receivers--all Onkyo--that support TrueHD. Does the player decode the audio and send the specific audio data to the receiver, or does it send raw data to the receiver to be decoded? I know the A2 can do TrueHD--can the PS3?

Oh, and can you really hear a difference (in 5.1) between these and regular (1.5Mbps) DTS?

 

[cmdrdredd]

Originally posted by: CMC79
What exactly do you need to have in order to hear these soundtracks? I have a PS3 and an HD-A2/360 add-on (I know the add-on is never going to have it). My current receiver is DD/DTS only; I've seen only a few receivers--all Onkyo--that support TrueHD. Does the player decode the audio and send the specific audio data to the receiver, or does it send raw data to the receiver to be decoded? I know the A2 can do TrueHD--can the PS3?

Oh, and can you really hear a difference (in 5.1) between these and regular (1.5Mbps) DTS?

I can hear the difference instantly. Most people would be happy with normal DD+.

To run TrueHD you need one of 2 hookup options.

1) a player with analog outputs to a reciver where the player decodes the audio.
2) a receiver with a TrueHD and DTS-HD decoder and use HDMI to bitstream the audio to the receiver for decoding.

The PS3 can decode TrueHD and DTS-HD (not Master Audio) and bitstream it to the receiver as PCM which supposedly offers no loss of quality. However I do not personally like this method. Most people wouldn't notice a difference though.

For what it's worth I run my Xbox 360 HD DVD player through my PC and can get all the available formats (except DTS Master Audio since PowerDVD currently does not support that format). I output the audio through analog out from my soundcard.

 

[CMC79]

So for option 2, something like this would be the thing to get, right?

 

[abaez]

Originally posted by: cmdrdredd

Originally posted by: CMC79

For what it's worth I run my Xbox 360 HD DVD player through my PC and can get all the available formats (except DTS Master Audio since PowerDVD currently does not support that format). I output the audio through analog out from my soundcard.

Does this result in any loss of quality? What if you bought a sound card that could output TrueHD or uncompressed to a receiver ? Would there be a difference?

 

[superbooga]

Originally posted by: abaez

Originally posted by: cmdrdredd

Originally posted by: CMC79

For what it's worth I run my Xbox 360 HD DVD player through my PC and can get all the available formats (except DTS Master Audio since PowerDVD currently does not support that format). I output the audio through analog out from my soundcard.

Does this result in any loss of quality? What if you bought a sound card that could output TrueHD or uncompressed to a receiver ? Would there be a difference?

Unfortunately PowerDVD has a problem where it will limit the quality of the analog outputs to 48Khz/16bit. Typically uncompressed PCM and TrueHD are 48Khz/24bit. Still, uncompressed/lossless compression is a noticeable step up from 448kbit DD and 768kbit DTS that we are used to on DVD.

 

[cubby1223]

Originally posted by: cmdrdredd
I see that spiderman 3 on Blu-Ray has Uncompressed PCM 5.1 and TrueHD. If TrueHD is lossless then what is the benefit(if any) to use Uncompressed PCM?

I've read comments that Spider-man's PCM and TrueHD soundtracks sound different, haven't kept up to see if anything was mentioned by Sony if they did any pre-processing to the audio before encoding it with TrueHD. They should be the exact same.

The benefit of one over the other isn't apparent to the consumer, but it makes a difference to the studio because TrueHD & DTS-HD-MA use less disc space and less bandwidth. I forget which title, I think it's Close Encounters of the 3rd Kind that will use multiple TrueHD tracks for different languages - it's something where you can use TrueHD tracks, but many PCM tracks would cut into the disc space and bandwidth too much.

 

[SlickSnake]

This is a clip I recently posted from another thread about HDMI here, but relevant to your question none the less. The link provided explains the difference about HD audio formats in relation to HDMI, which we are all interested in, I think.

HDMI Version Revisons FAQ

Why You DON'T Need HDMI 1.3 (yet)

Read this FAQ to see that nearly all HDMI improvements and additions are related to the video part of the specification. While it is true with HDMI 1.3 it adds support for HD enhanced audio, you can still get that HD audio via PCM instead. And when you see the list of revisions with each new version, you can understand why H/K is still using HDMI 1.1. I am sure H/K plans a revision soon to HDMI 1.3 and they haven't yet done so because until this version, the audio portion of these various revisions really didn't warrant the added expense of adding it at that time. Who cares about HD quality audio coming out of crappy 10 or 15 watt 2 channel stereo TV speakers? I sure don't.

Similarly, most true audiophiles will not willingly run the video through the HT receiver unless they expect to gain something out of it, like DCDi® by Faroudja video processing, which H/K includes on the current flagship model and some others.

Now, if you expect to use your HT receiver as a cheap substitute for a high quality HDMI 1.3 video switch box, then yea, this might be a sticking point for you. Not all manufacturers will include all HDMI revision update options in all products, and a just because a said manufacturer claims to support this revision, does NOT mean they will support all the features associated with it. All they are claiming is the pass through capability to use HDMI 1.3 at that revision level. And when you see the long list of all the features each new revision offers, you can begin to understand why this is so.

 

[SlickSnake]

Originally posted by: CMC79
So for option 2, something like this would be the thing to get, right?

Notice in the add it says: HDMI V1.3 repeater (2in/1out, 1080p compatible)

This is what I mean when I refer to PASS THROUGH in my previous post. It completely passes the signal for the spec for HDMI 1.3, but does it actually implement it properly? Yea, the pretty TRUEHD light comes on if it detects an HD Audio signal, but it would also be detected in PCM mode.

 

[destrekor]

Originally posted by: cubby1223

Originally posted by: cmdrdredd
I see that spiderman 3 on Blu-Ray has Uncompressed PCM 5.1 and TrueHD. If TrueHD is lossless then what is the benefit(if any) to use Uncompressed PCM?

I've read comments that Spider-man's PCM and TrueHD soundtracks sound different, haven't kept up to see if anything was mentioned by Sony if they did any pre-processing to the audio before encoding it with TrueHD. They should be the exact same.

The benefit of one over the other isn't apparent to the consumer, but it makes a difference to the studio because TrueHD & DTS-HD-MA use less disc space and less bandwidth. I forget which title, I think it's Close Encounters of the 3rd Kind that will use multiple TrueHD tracks for different languages - it's something where you can use TrueHD tracks, but many PCM tracks would cut into the disc space and bandwidth too much.

well this is not normally the case (TrueHD sounding superior), and I have a feeling you read the HighDefDigest review for Spiderman 3, which in the audio section claims the TrueHD track is possibly superior with slightly better dynamics. Who knows, it's not something easily noticeable I bet, and I'll give both a shot and see if one sounds better to me, if either.

 

[zinfamous]

Originally posted by: SlickSnake

Originally posted by: CMC79
So for option 2, something like this would be the thing to get, right?

Notice in the add it says: HDMI V1.3 repeater (2in/1out, 1080p compatible)

This is what I mean when I refer to PASS THROUGH in my previous post. It completely passes the signal for the spec for HDMI 1.3, but does it actually implement it properly? Yea, the pretty TRUEHD light comes on if it detects an HD Audio signal, but it would also be detected in PCM mode.

I have the PS3 pumping bitstream into the Onkyo 605. I can't get TrueHD b/c (as is my understanding from the Onk's manual), I don't have a full 5.1 (maybe even need a 7.1 setup--although it does list TrueHD 5.1) hooked up to the receiver.

Can anyone shed any light on this? I'm assuming that all I need to do is hookup a sub and all of the TrueHD/PCM options will become available through the receiver.

One thing I have learned, is that you need to set the PS3 to Bitstream output. Setting it to PCM will default all audio output to PCM, regardless of what you tell the receiver to do. I don't see any benefit to PCM in my setup, as all PCM options simply output the same audio track to each speaker, eliminating all surround effects. Pretty crappy, if you ask me. I assume this will all change if I add a sub (both PCM available options and Bitstream/TrueHD?)....

 

[zinfamous]

Originally posted by: cmdrdredd
So Uncompressed PCM and TrueHD are the same bitrate etc?

bitrate is FUD. very similar to the marketing FUD that has lead many to believe that MP is the most important aspect of quality in a digital camera.

From what I understand, there is very little reason to even look at bitrate. All codecs and cables are capable of achieving any bitrate that will be necessary for the forseeable future.

 

[cmdrdredd]

Originally posted by: abaez

Originally posted by: cmdrdredd

Originally posted by: CMC79

For what it's worth I run my Xbox 360 HD DVD player through my PC and can get all the available formats (except DTS Master Audio since PowerDVD currently does not support that format). I output the audio through analog out from my soundcard.

Does this result in any loss of quality? What if you bought a sound card that could output TrueHD or uncompressed to a receiver ? Would there be a difference?

The quality loss is minimal it doesn't support the full 24/96 because PC soundcards currently have no HDCP features enabled that protect the stream from being intercepted. Soonish (I hope) there will be a upgrade for this.

 

[cmdrdredd]

Originally posted by: destrekor

Originally posted by: cubby1223

Originally posted by: cmdrdredd
I see that spiderman 3 on Blu-Ray has Uncompressed PCM 5.1 and TrueHD. If TrueHD is lossless then what is the benefit(if any) to use Uncompressed PCM?

I've read comments that Spider-man's PCM and TrueHD soundtracks sound different, haven't kept up to see if anything was mentioned by Sony if they did any pre-processing to the audio before encoding it with TrueHD. They should be the exact same.

The benefit of one over the other isn't apparent to the consumer, but it makes a difference to the studio because TrueHD & DTS-HD-MA use less disc space and less bandwidth. I forget which title, I think it's Close Encounters of the 3rd Kind that will use multiple TrueHD tracks for different languages - it's something where you can use TrueHD tracks, but many PCM tracks would cut into the disc space and bandwidth too much.

well this is not normally the case (TrueHD sounding superior), and I have a feeling you read the HighDefDigest review for Spiderman 3, which in the audio section claims the TrueHD track is possibly superior with slightly better dynamics. Who knows, it's not something easily noticeable I bet, and I'll give both a shot and see if one sounds better to me, if either.

Let me know what you think. I'm interested in a home user's experience more so than a controlled test.

 

[cmdrdredd]

Originally posted by: zinfamous

Originally posted by: SlickSnake

Originally posted by: CMC79
So for option 2, something like this would be the thing to get, right?

Notice in the add it says: HDMI V1.3 repeater (2in/1out, 1080p compatible)

This is what I mean when I refer to PASS THROUGH in my previous post. It completely passes the signal for the spec for HDMI 1.3, but does it actually implement it properly? Yea, the pretty TRUEHD light comes on if it detects an HD Audio signal, but it would also be detected in PCM mode.

I have the PS3 pumping bitstream into the Onkyo 605. I can't get TrueHD b/c (as is my understanding from the Onk's manual), I don't have a full 5.1 (maybe even need a 7.1 setup--although it does list TrueHD 5.1) hooked up to the receiver.

Can anyone shed any light on this? I'm assuming that all I need to do is hookup a sub and all of the TrueHD/PCM options will become available through the receiver.

One thing I have learned, is that you need to set the PS3 to Bitstream output. Setting it to PCM will default all audio output to PCM, regardless of what you tell the receiver to do. I don't see any benefit to PCM in my setup, as all PCM options simply output the same audio track to each speaker, eliminating all surround effects. Pretty crappy, if you ask me. I assume this will all change if I add a sub (both PCM available options and Bitstream/TrueHD?)....

The PS3 from what I've read decodes the trueHD and bitstreams it out as PCm to the receiver. Supposedly no quality loss. Not really trueHD but again supposedly no loss in quality. I don't know...I don't have a PS3.

 

[cmdrdredd]

Originally posted by: zinfamous

Originally posted by: cmdrdredd
So Uncompressed PCM and TrueHD are the same bitrate etc?

bitrate is FUD. very similar to the marketing FUD that has lead many to believe that MP is the most important aspect of quality in a digital camera.

From what I understand, there is very little reason to even look at bitrate. All codecs and cables are capable of achieving any bitrate that will be necessary for the forseeable future.

The higher the bitrate the MORE data is being processed at one time thus more of the original audio is preserved. That's why DTS 5.1 IS better than DolbyDigital 5.1 it has more bandwidth.

 

[cmdrdredd]

Originally posted by: SlickSnake
This is a clip I recently posted from another thread about HDMI here, but relevant to your question none the less. The link provided explains the difference about HD audio formats in relation to HDMI, which we are all interested in, I think.

HDMI Version Revisons FAQ

Why You DON'T Need HDMI 1.3 (yet)

Read this FAQ to see that nearly all HDMI improvements and additions are related to the video part of the specification. While it is true with HDMI 1.3 it adds support for HD enhanced audio, you can still get that HD audio via PCM instead. And when you see the list of revisions with each new version, you can understand why H/K is still using HDMI 1.1. I am sure H/K plans a revision soon to HDMI 1.3 and they haven't yet done so because until this version, the audio portion of these various revisions really didn't warrant the added expense of adding it at that time. Who cares about HD quality audio coming out of crappy 10 or 15 watt 2 channel stereo TV speakers? I sure don't.

Similarly, most true audiophiles will not willingly run the video through the HT receiver unless they expect to gain something out of it, like DCDi® by Faroudja video processing, which H/K includes on the current flagship model and some others.

Now, if you expect to use your HT receiver as a cheap substitute for a high quality HDMI 1.3 video switch box, then yea, this might be a sticking point for you. Not all manufacturers will include all HDMI revision update options in all products, and a just because a said manufacturer claims to support this revision, does NOT mean they will support all the features associated with it. All they are claiming is the pass through capability to use HDMI 1.3 at that revision level. And when you see the long list of all the features each new revision offers, you can begin to understand why this is so.

So if you are running a Blu-Ray or HD DVD player out to a receiver how else do you get the video signal? You have only the option of using the multichannel outs or bitstreaming the audio through HDMI. If you use HDMI then you have to run the video through your receiver then out to your TV. Since HDMI is 100% digital there should be no tangable loss in quality. Correct? Assuming the receiver is not doing anything with the video except passing it through.

 

[SlickSnake]

Yea, I see your point, in theory. But you will note in the FAQ the video specifications also change over longer runs on HDMI. I believe this is due to loss of signal quality and integrity, so every connector in the line will degrade video quality to some degree, if this is the case.

Q. What are the technical and branding requirements for cables?

As part of the new Trademark and Logo Usage Guidelines, cables will be labeled as either Standard or High Speed.

1. Standard cables (referred to as Category 1 cables in the HDMI specification) are those tested to perform at speeds of 75Mhz, which is the equivalent of an uncompressed 1080i signal.
2. High Speed cables (referred to as Category 2 cables in the HDMI specification), are those tested to perform at speeds of 340Mhz, which is the highest bandwidth currently available over an HDMI cable and can successfully handle 1080p signals including those at increased color depths (e.g. greater than eight bits per color) and/or increased refresh rates (e.g. 120Hz). High Speed cables are also able to accommodate higher resolution displays, such as those at the latest 1440p and WQXGA resolutions (e.g. cinema monitors with a resolution of 2560 x 1600).

While many cables that are branded as Standard cables will work at higher speeds (especially at cable lengths of less than five meters), to guarantee performance, consumers should purchase a cable that is tested and rated for the specific speed required by their system.

and

Q. Does HDMI accommodate long cable lengths?

Yes. HDMI technology has been designed to use standard copper cable construction at long lengths. In order to allow cable manufacturers to improve their products through the use of new technologies, HDMI specifies the required performance of a cable but does not specify a maximum cable length. We have seen cables pass ?Standard Cable? HDMI compliance testing at lengths of up to a minimum of 10 meters without the use of a repeater. It is not only the cable that factors into how long a cable can successfully carry an HDMI signal, the receiver chip inside the TV or projector also plays a major factor. Receiver chips that include a feature called ?cable equalization? are able to compensate for weaker signals thereby extending the potential length of any cable that is used with that device.

With any long run of an HDMI cable, quality manufactured cables can play a significant role in successfully running HDMI over such longer distances.

Q. How do I run HDMI cables longer than 10 meters?

There are many HDMI Adopters working on HDMI solutions that extend a cable?s effective distance from the typical 10 meter range to much longer lengths. These companies manufacture a variety of solutions that include active cables (active electronics built into cables that boost and extend the cable?s signal), repeaters, amplifiers as well as CAT5/6 and fiber solutions.

So, to achieve a less noisy or degraded video signal over longer runs, I guess you would have to run separate cables, using a powered HDMI switch box, which is somewhat defeating the purpose of the HDMI cable in the first place. The fact is most receivers use just a pass through HDMI connection, and that fact alone would have to degrade video or audio quality.

 

[destrekor]

Originally posted by: cmdrdredd

Originally posted by: zinfamous

Originally posted by: cmdrdredd
So Uncompressed PCM and TrueHD are the same bitrate etc?

bitrate is FUD. very similar to the marketing FUD that has lead many to believe that MP is the most important aspect of quality in a digital camera.

From what I understand, there is very little reason to even look at bitrate. All codecs and cables are capable of achieving any bitrate that will be necessary for the forseeable future.

The higher the bitrate the MORE data is being processed at one time thus more of the original audio is preserved. That's why DTS 5.1 IS better than DolbyDigital 5.1 it has more bandwidth.

that's NOT guaranteed to be true. the thing is, DTS and Dolby use two completely different compression techniques, and Dolby has a superior compression algorithm. However, while a DTS track was larger simply due to not as efficient compression, it was also larger because it did want to present superior audio to the listener.
however, while in this case it is true, more bitrate isn't guaranteed to present better quality audio since compression algorithms differ amongst companies, and thus one may actually produce a higher quality audio track while actually having a lower bitrate.

to use a more fitting example, look to uncompressed PCM, TrueHD and DTS HD-MA. TrueHD, at least of tracks I have seen, my PS3 reports usually around 4mbps. The PCM tracks I have encountered, and when I used the PS3 to look at the bitrate, was always around 5-6.5mbps. DTS HD-MA? No clue, as the PS3 cannot touch that as of yet.

Why all three exist, I have no clue, especially considering all are supposedly lossless. Now, obviously there is a difference in bitrate, and there is a such thing as lossless compression, so keep that in mind. Dolby likely uses light compression when wrapping the audio into the TrueHD codec, versus straight PCM audio.
I assume PCM audio really was only around as a filler in-between the period of BD introduction (do any HD DVD titles have PCM audio?) and adoption of HDMI v1.3 spec receivers. That's my guess and it makes sense, to allow those who do not have capable receivers, and players not capable of internal decoding, to still enjoy HD audio. Is that the real reason? Who knows. Maybe it's simply to avoid fees for using codecs of the audio companies, as PCM, I assume, is free to use since it's really not a codec, just a transmission standard?


and I have my own question:
is it possible to add HDMI v1.3 spec audio track decoding through a firmware update to a v1.1 spec receiver, such as my H/K AVR247? I honestly doubt it and have no hopes, but it's an interesting idea. Would be awesome if possible.

 

[SlickSnake]

The high definition audio standards war is more about who pays who royalties than about what standard is superior to another, just like the current HD versus Blueray war. These wars are won based on who charges less royalties to license the products.

Remember HDCD? that is a perfect example of greedy licensing fees killing off a perfectly good product inovation before it ever really had a chance to get off the ground. Otherwise, all CDs marketed today would be mastered at the higher bit rate. Even the HDCD players play back regular CDs with improved clarity, but look at how few makers even support it. H/K still makes their 5 disk CD changer that supports HDCD playback like 4 years later after it was introduced, just because the regular CD audio quality is improved, not because this format ever really took off.

And because the specifications change on the HDMI so frequently, I don't think a simple firmware update would work to support it. I have wondered that myself, and really didn't see any answers to that question anywhere I looked. But if the version of HDMI you use on a DVD player is for example 1.3 and the receiver is 1.1 and the TV is also 1.3 I can't see any reason why it would not pass the improved video or audio to the TV if it is only a pass through. Now, if it actually altered the HDMI signal somehow, like those receiver chips previously mentioned in that FAQ, then who knows what would happen. It would depend on whether the chip supported up and down conversion of the HDMI specifications.