High-Def FAQ: Uncompressed vs. Lossless Audio

Joshu Zyber writes, "A couple of months ago, I wrote a column called Blu-ray and HD DVD Audio Explained that spelled out the basic functions, features, and differences among the various audio formats available on both High-Def disc types. In it, I explained that uncompressed PCM audio (as found on many Blu-rays) is an exact replication of the studio master, encoded on disc without compression, and that the lossless audio formats Dolby TrueHD and DTS-HD Master Audio are also bit-for-bit identical to the studio master once decoded. Doing the math, that should mean that a lossless track is also identical to an uncompressed track. Indeed, that is the case. However, some confusion remains as to whether an uncompressed track is actually better than a lossless one."

"The number of new audio formats on Blu-ray and HD DVD have caused a great deal of consumer confusion, especially with three separate formats (PCM, Dolby TrueHD, and DTS-HD Master Audio) all designed to accomplish the exact same goal -- a perfect replication of the movie's audio master. Apprehensions about lossless compression being inferior to an uncompressed version of the same soundtrack are not borne out by the facts. One methodology may have technical advantages over the other in terms of space savings, but the end result is the same whether the disc you buy has an uncompressed soundtrack or a lossless one. They're both equally good, so sit back and enjoy."

[Lord Anubis]

what a waste of time reading absolutely nothing but a person going in circles to justify D true-HD. Uncompressed carries the true track while the others drop what they call white noise to reduce the size of the track.

[jaja1434]

See your comment alone tells me you didn't read the article. Had you actually read it you would know thats not how this type of audio compression actually works.

What you said is basically how an mp3 works and to a lesser extent a wav. Perhaps next time a quick read would be better?

[blackmagic]

I think you are confusing the section on lossy compression with lossless compression. The whole point of lossless compression is being 'lossless' in other words identical to the original sample. As he points out in the article, the Linear PCM track or Lossless track could still be a downsampled 16 bit version of the master audio for various reasons from disc space issues to the Master not being a high enough quality to begin with as is the case in many older movies. Joshua Zyber is an exceptional columnist in the industry.

[power of Green]

Who cares really... Sold my HD-A2 because I found out I'm getting a HD-A35 for Xmas. I have a Yamaha HTR-5940 AV Recever with an BIC Venturi DV62CLR-S 6.5” 2-Way Center Channel Speaker with two sets of
Bose Acoustimass 5 Series III Speakers for surround sound.

My system's hardly a sound setup that has me worried about the content of this post as if I know what it all means. All I no is I do not have $10,000 tower speakers etc as my set up is average.

[green]

same here.i will just get the HD-DVD add on for the 360.HD-DVD is cheep and i don't have the financial power yet to buy a PS3 because i want to watch HD movies.Its just storage space that is the difference.And i like hd-dvd feature of making dvd on one side and hd-dvd on the other so even if hd-dvd fails i wouldn't have lost much because my movies will still play on a regular DVD.

[IGNFTW]

AND I CAN TELL YOU WITHOUT ANY HESITATION: BLU-RAY HAS BETTER AUDIO QUALITY.
PERIOD.

[jaja1434]

Playing Guitar Hero does not mean you make music. :)

[jaja1434]

Interesting read. I already learn most of that this semester when we studied compression techniques, but still very Interesting.

Now will this stop the "loss less is worse than..." crap that goes on in the HD vs BR threads?

[ITR]

Read the new Harry Potter movie review on HD Digest..the reviewer basically says I can't tell the difference between the two.

[Antiomo]

Blu-ray discs tend to have loseless sound .... hd-dvd does not, most of the discs are still stuck in the past with standard Dolby Digital and DTS

edit: Hate to break it to you ITR but most hd-dvd's do not have losless sound. about 25% do have losless sound

If you look at the major players of blu-ray buenea vista almost guarantees has pcm, Sony studios same thing, and fox dts-hd.

The only company bringing blu-ray's percentage down is warner, but they are a neutral studio.

[ITR]

What?
Harry Potter OP - Dolby TrueHD 5.1
Mr. Bean - Dolby TrueHD 5.1
A Clockwork Orange - Dolby TrueHD 5.1
Many HD movies have DTHD 5.1 sound.
So I guess your complaining about DD+ then. I hate to break it to ya, but you can find DD+ on many BD titles too...especially movies 15-30+- yrs old.

[blackmagic]

Actually, Blu-ray is the only disc that uses the old Dolby Digital CODEC as it's primary audio track. 123 titles or about 30% of all Blu-ray releases are Dolby Digital. You are correct that the majority of them are from Warner. HD DVD has not used the Dolby Digital CODEC on a single release as it's primary audio. Dolby Digital Plus is used on 86% of releases and Dolby Digital TrueHD is used on about 20% of releases and both represent the latest techniques in audio compression.
http://www.blu-raystats.com...
http://www.hddvdstats.com/i...

[Guwapo77]

That was a very interesting read. All this time I felt that PCM was superior to DTS-HD and Dolby HD because of something called Dailnorm. When switching through the different setting in the PS3, you can instantly tell the difference in sound. The voices and sound effects seemed louder doing PCM than DTS-HD. But its just because they use a technic that in my eyes is pretty worthless. I'll throw 300 back in tonight and listen for the differences.

Sony XBR2 40 HDMI 1.2 (gotta up grade to HDMI 1.3 next year)
Onkyo SR-705 HDMI 1.3
7.1 speakers (Sony tower (best they offer) surrounds eh...cheap and Yamaha powered 10" sub) Will upgrade to Polks later.

For years played on standard stereo/simulated surround sound system/speakers. I must say, true surround sound is a must that loves movies and video games. I barely like watching movies at the theater anymore. Thanks to Hi-Def in the home...the experience is so much more satisfying.

[ITR]

When the reviewer at HD Digest reviewed the new Harry Potter movie he said initially the PCM was louder then DTS-HD, then he level matched and they basically sounded the same.

[Guwapo77]

I'm still confused as to why they would add a feature like that...

In the end, a little knowledge goes a long way.

[fopums]

my hearing isnt great, so I doubt I could actually tell the difference. With all the noise people deal with everyday our hearing has to be degrading faster then ever, so I wouldnt be suprised if I was in the majority.

people who cant "hear" high def. unless you dont blare your speakers, but whats the fun if you dont :p

[Antiomo]

because they eitehr dont have the right equipment or the speakers are not setup properly.

I just demo'd Underworld to a few friends and they did not believe it till I switched back and forth between pcm to dolby digital. In the end they felt convinced that there was a big difference.

[funkysolo]

Wether or not the difference is minimal it's still a difference. Do you know there's speakers that cost $20,000 and more. Why would someone buy these expensive speakers if they can get the same sound on bose, right? Come on now with the right equipment theirs a difference, space shouldn't be a factor and that's where blu ray wins. Both formats are equal but the space is where blu ray has the upperhand. Just like those people that pay all that money for their equipment to get every bit of sound and video as possible. You all brokeazz thinks that the world revolves around you it doesn't. People that went out and bought those $1000 bluray players to get 1080p deserve to get top sound and video. They could of easily went with HDdvd and got 1080i for $600. That's you xbots excuse- 1080i looks as good as 1080p, uncompressed sounds as good as PCM...those are excuses nothing more. I want true HD1080p and uncompressed sound, DTSHD, DDHD, PCM. I want the format that offers more without comprise to win, not the inferior format.

[blackmagic]

Here we go again.
1. 1080i60 and 1080p60 signals are both capable of carrying a 1080p24 source without loss. 1080p60 just repeats data. Actually 1080i60 also repeats some data but not as frequently as 1080p60. If there is a degradation, it is due to the television having a poor/cheap de-interlacer built into it not because there is missing data in the 1080i60 datastream.
http://blog.hometheatermag....

2. If you own a 576p, 720p, 768p, 1080i or one of the oddball 1024x1024 or 1024x1080 resolution HDTVs then why would you want to spend $100-$200 more just to get a player that outputs 1080p, a feature that is useless to you? Be smart, if you own one of these sets, save your money and when you upgrade to a 1080p set in the future, use that saved money to upgrade to the latest 1080p player. It'll likely be less than $100 by then.

3. Only the entry level Toshiba player is 1080i. All other players are 1080p. All the encodes on HD DVD discs are 1080p.

4. The most expensive HD DVD player currently being made by Toshiba is only $549 MSRP and can easily be found for about $450. One retailer on Amazon even has it priced at $345. Kind of ironic that the most expensive Toshiba HD DVD player can be found for less than the MSRP of the least expensive Blu-ray player.
http://www.amazon.com/gp/of...

5. The HD DVD consortium knew from the beginning that they would need to work with smaller disc space in order to leverage the advantages of the installed hardware manufacturing and disc printing processes (this is why HD DVD is so much less expensive in every way) as a result they incorporated certain standards into their technology which allowed them to deliver the same quality with less space. Thomson's Film Grain technology, which is mandatory on HD DVD but has no inclusion on Blu-ray at all, allows the same quality video to be achieved while using less space. The mandatory inclusion of Dolby Digital Plus and Dolby Digital TrueHD CODECS allow the same quality audio encodes as Linear PCM while using significantly less space. As a result, over 4 hours of film can be held on a single HD DVD, more than enough for any film I am aware of. Regardless, any talking point advantage that Blu-ray had on disc space has been elimnated by the TL51 disc.

6. If PCM tracks are so much better why is it that a Dolby Digital Plus track on Transformers won the 'Best Audio Quality' category at the High Def Disc Awards beating out ALL lossless audio tracks on both formats? If industry professionals think the Transformers audiotrack was top notch beating out all those lossless tracks on both Blu-ray AND HD DVD, I'd say that pretty much deflates the sales of anybody who tries to imply that lossless tracks are perceptively better than the latest compression techniques, don't you?
http://www.nxtbook.com/nxtb...

7. If you think that spending more money on a format that looks better on paper but has no perceivable differences in practice is wise, then that is your choice.

[Guwapo77]

bubble.

*edit* Screwed up there...failed to reply @ 9.