dolby TrueHD vs PCM difference in bitrate?

What you're talking about isn't the bit rate, but the bit depth.

I hate to nitpick, but...

Really, "most" are 48/24? Looking at the spec thread in the BD forum, I would say that "most" are 48/16.

-John

I think most people would be happy with TrueHD or PCM. Both are lossless and get us close to the master. Dolby Digital Plus is what needs to go away.

I agree that HD-DVD needs to get larger disc capacity...and soon. We are already seeing compromised audio due to the size limitation. (Transformers). Paramount chose extras over sound quality and something had to be sacrificed. Why not just put extras on a second disc, especially for such a blockbuster title?

With more disc space they wouldn't have to sacrifice either one.

You don't really think space is the reason why Transformers doesn't have TrueHD, do you?

What other reason is there?

Same reason Paramount doesn't put TrueHD on most of their releases.

Thanks for clearing that up?????

Here are the extra features listed for Transformers:
Disc Features:
• Audio Commentary with director Michael Bay
• 2 Four-Part Documentaries: "Our World," "Their War"
• Featurette: "From Script to Sand: The SKORPONOK Desert Attack"
• Still Gallery: "Concepts"
• Theatrical Trailer

HD Exclusive Content:
• Picture-in-Picture: "TRANSFORMERS H.U.D. (Heads Up Display)"
• "RANSFORMERS Tech Inspector"
• Web-Enabled Content: "Transformers Intelligence Mode"

That is why I believe it is disc space that forced them to use a lossy audio format.

Exactly, Look at it this way, maybe there is a reason why both Paramount and Universal chose 24bit 1.5mbs. There is a Large degree of diminishing returns. DD+ is an HD audio codec no matter what anyone says, and if the mixers can't tell the difference or think that the difference is so small, why waste the extra space on it.

So what I stated is the truth then. It is a space limitation with HD-DVD and until they increase storage capacity it will come down to extras or lossless audio being sacrificed. They should offer the best possible video and audio for the film itself and then add as many extras as they can fit on the disc. Extras should not take priority over the film itself.

Does anyone have information on the development of the 51G HD-DVD ?

1.) That list isn't very big
2.) How long is the movie
3.) Its a two disc set.
4.) The Movie is shorter then King Kong by 40 minutes
5.) The movie is Coming out on disc a year after Kong
6.) VC-1 and AVC have had well over a year of practice making them more efficient
7.) That even at the same bit rate for video (lets say 13mbs which is a really conservative number) that equals 4GB storage saved.
8.) The DD+ track is only 1.6 GB.

Honestly I firmly believe if they wanted a TrueHD track they could have, I think they chose not two because they didn't see a reason for it.

Well that is too bad then. If there was room for lossless and they chose a lossy format, I stand by my dissappointment that they are not offering the best audio the format is capable of.

And like it or not, the competition is offering lossless audio.

Wow where did you get that from. I said that Paramount and Universal havn't been using TrueHD for a reason being diminshing returns.

Think about it there is always a capacity limitation otherwise we would be getting 200GB discs.

What I was saying that the mixers for both companies probably didn't find a good enough or audible enough reason to waste both time and effort on a TrueHD encode compared to their super high bitrate and depth DD+ tracks. The fact that a DD+ track is by default going to be on any disc even if they do decide to do a TrueHD track, wouldn't it just make more sense to just make the DD+ track sound as close to the TrueHD as possible (maybe even matching it) and not have to do due encodes.

Its been green lighted for production based testing.

No, that's not the "truth." That is called your taking an assumption or opinion or theory, and then saying it is "fact"

There's a big difference.

Note how I did not say your opinion/theory is incorrect, but it's certainly not "fact" until someone actually confirms the reason for the lack of lossless on Transformers. All we have now is a bunch of people saying it's due to HD DVD's limitations, with no facts to actually back it up. My apologies if you were actually sitting in the encoding room when they said "Nope, there's no way we can fit lossless on this disc"

Be disappointed I don't care because you have no basis for your belief that you would be getting a lesser product. They are offering lossless well so are Weinstein, Universal, Warner, Dreamworks, and many more on HD-DVD. That said besides using the name lossy can you really prove that you are losing out on even the most minuscule of audible sound?

None of us know this for a fact since we don't work for Paramount. So we are just jumping to conclusions. This is a two disc set so they extras could be all on the second disc. Honestly I dont think its a space decision but one made by the studio for there own reason.

As for 51 HD-DVD I think it has been officially approved but no one knows if and when it is coming to production.

I noticed you didn't respond this way to other people claiming it wasn't a disc space issue. I'm assuming they weren't there either.

Lossy means samples are thrown away. Lossless means they are not. To me that is common sense.

Lossy and lossless are compression methods, nothing to do with sound quality.

Wikipedia:
Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data.

This can be contrasted to lossy data compression, which does not allow the exact original data to be reconstructed from the compressed data.

which is in all likelihood inaudible to you anyway, so what is the fuss about?

the quality of the mastering has a greater impact on the sound that you hear...

Yes but the question that really needs to be asked are what exactly is lost and is it perceivable to the listner. A good job can be done with lossy in that whats lost is masked or not percieved. The advantage with lossless is that it gives a more accurate representation of the original and if done correctly offers an advantage over its lossy counter for the same track. A really good sound engineer can make a great sounding lossy sound track especially if it was a great source to begin with. Think of film prints that do not get cleaned up and mastered before the get put on a hidef disc all the ugliness comes shining through and people criticize the image to no extent. In this case it is not the codec thats at fault but the handling of the original source.

Back to the op original thread. The difference between 48/16 and 48/24 would mainly show up in the ability to extend the frequency response 22khz and above and the dynamic range possible by the system. 48/16 dynamic range limit is around 100db I believe maybe slightly less. Considering that the average noise floor in an average room filled with electronics is about 24db then your playback level would need to be exceedingly high to begin to run into dynamic compression. As such you are sooner to run into the limitations of other components in the chain than the ability of the system to produce this type of dynamic range. 48/24 I think is above 120db in dynamic range giving you a great swing capability. Also the frequency response is more extended. As to whether or not it these differences are percievable for most systems in most rooms is debatable.

The Question is is there an audible difference between one and another, second even when using a lossy codec if given enough bandwidth you lower the amount of tossed bits. If mixed correctly hand treated well by the compressionist why is it so hard to believe that you might just in fact begetting the best version.

Exactly, they are compression methods. There is nothing to say that the Lossy can't sound as good or even better than lossless.

While I can appreciate the desire to get the best possible audio and video there is a point when good enough is exactly that. Your assumption that no lossless track was included because of space limitation is just that and assumption. At the vary least we need to wait until we get the disks and can look at the size of the video and how much space is used on both disks. Personally I find it unlikely that the 2 disk set didn't have space to fit a lossless track if they wanted one. More likely they decided that the DD+ track was good enough people wouldn't be able to tell the difference. Rent the movie and listen to it before you decide if the audio track is crap or not.

I found the following site interesting. http://www.soundexpert.info/ It is setup to do blind testing of audio compression/decompression codecs by compressing and then decompressing an audio sample and then having people do blind evaluation of the results in a wave file along side the original. The net result is that at 256 kbps for a stero track their test show the average rating is that "all sound artifacts will be beyond threshold of human perception with corresponding perception margin" or people can't hear the difference. 6 channels at this rate would only be 768kbps or half the encode rate of the 5.1 paramount is using for Transformers.

Obviously this isn't a perfect setup since we do not know the quality of peoples speakers etc but even then we're still doubling our bit rate and using a fairly recent codec that may be more efficient than the ones we are comparing it to.

Sighting Disc capacity as being the reason for the lack of a lossless track on this title is an assumption on your part. There is no proof of this.

"Why not just put extras on a second disc, especially for such a blockbuster title?"

That's exactly what Paramount did. This is a two disc release with the extras being on the second disc.

This is a Paramount business practises issue and not a HD DVD technical issue.

In other words, it is "good enough"?

IMO that is too much of a "motherhood" statement, which means you can use it to justify anything.

The quality of the mastering has a greater impact on the sound that you hear, therefore MP3 is just as good as PCM.

The quality of the mastering has a greater impact on the sound that you hear, therefore 8-track tapes sound just as good as HD-DVD.