Weird thing about review of audio here....

[ryoohki]

Ok let's clear things first and foremost.

1 - STUDIO don't decide the bitrate of a TrueHD Track/DTS HD Track (a lot of time DTS track are higher because they are 24bits). This Bitrate is VARIABLE and is calculated on the compression side. When they run all the 6 or 8 track to the compressor, it loselessly compress the date. The more complex is the WaveBand, the less it compress. If you have a movie with a LOT of sound allways in a speaker, you gonna have a bitrate of 3-4, if you have almost only sound in the front (like a lot of movie MONO to 5.1) you gonna end up with 1.5-2.5mbits at most.

Other thing influence that, the Bits. If it's 16bits or 24bits. 16bits compress better than 24

Because i see the review of Full Metal Alcheimist complain that not enought bitrate was given to the japanese track.

well they can't reallly do nothing about it. If you're master is crappely done (mixed in surround in wierds ways) you gonna end up with a smaller file becase the CODEC IS DOING HIS JOB!

If you have a great experience with FLAC codec on PC you'll understand all this and how a Calm and relax album end up being 300meg(off 600 originally) at 650kbs/sec (example) while than other is busy all the song and you end up at 500meg (of 600) with 1mbits bitrate

[Afrobean]

I read this review and laughed to myself about that too.

It could be the source was a lower quality while still lossless, but the general idea is that it's absurd to complain about low bitrates in lossless codecs. The bitrate is EXACTLY where it is supposed to be given the source material.

Probably could have PM'd the reviewer regarding this though.

[BozQ]

Originally Posted by ryoohki

(a lot of time DTS track are higher because they are 24bits).

You're pretty much right about everything except for this.
Dolby TrueHD is very capable of compressing 24-bit LPCM too.
And there have been TrueHD tracks in 24-bit too.

[Ken Brown]

Alas, reviewers aren't all-knowing machines. We rely on information and correction to hone our reviews and to increase our knowledge on a variety of subjects. But please keep in mind that people devote their entire lives and careers to mastering just one aspect of the filmmaking process; we're tasked with evaluating every aspect of the results. Unfortunately, that means we aren't always aware of bits of technical information (much like the one you pointed out). However, instead of getting upset, it would be far more beneficial for everyone involved if you:

1) PM a reviewer when you notice an error or inaccuracy. I think we're pretty nice fellows, and I can assure you none of us are above correction We covet your feedback and your expertise in areas we don't have the luxury of having extensive training in. I soak up information like a sponge, and I think my reviews improve accordingly. I'm sure you'll find Dustin and the other staff members here are the same.

2) Keep in mind that we make faulty assumptions sometimes too. We're just people; people who can assume one thing until we're informed of another. Especially when it comes to evaluating the look and sound of a presentation, hardly the easiest thing to convey through the written word.

3) Provide clear details (as you did) and refer to sources we can utilize to further educate ourselves on the topic at hand.

Ultimately, please understand we value this sort of feedback. We appreciate PMs or posts that help us correct a faulty assumption or error. But please don't wait until you reach a boiling point to say something -- there's no need to be frustrated, there's no need to assume we have anything but the best of intentions in mind, and there's no need for anyone to get upset. Again, I would suggest contacting a reviewer directly when you notice this sort of thing. We're quick to make changes and correct those inevitable (hopefully minor!) things we get wrong.

Thanks as always for posting!

[kpkelley]

If, as you say, the track itself is what determines the variability of the bit-rate for the lossless audio track, how can the same movie be compressed with the same codec by different studios result in different bit-rates?

This is from the Gomorrah comparison at DVDBeaver. You will notice that the bitrate on the Optimum disc is 2465kbps DTS-HD MA, while the Criterions is 3761kbps DTS-HD MA.

The only track available is a DTS-HD 5.1 in Italian at 2464 kbps. I didn't get much from the surround option - even with the heavy gunplay - and it seems most of the action was coming predominantly from the front speakers. I wouldn't say this is a bad thing although some anticipating a more dynamic mix may be disappointed. There are optional English subtitles and my Momitsu tells me this is a region 'B'-locked Blu-ray.

Similarly the only track available on the Criterion is a DTS-HD 5.1 in Italian - but at, a higher, 3761 kbps. Technically it is a bit more robust but I, honestly couldn't say I noticed. The Criterion may have been better separated but again, I don't know who would be able to differentiate. There seemed to be more subtleties in the mix but I don't know how reliable my opinion on this is. Suffice to say the Criterion surpasses the Optimum - if only a strictly technical, if not also practical, basis. The Criterion also has removable English subtitles and is region 'A'-locked.

Link

[Jeff Kleist]

If, as you say, the track itself is what determines the variability of the bit-rate for the lossless audio track, how can the same movie be compressed with the same codec by different studios result in different bit-rates?

This is from the Gomorrah comparison at DVDBeaver. You will notice that the bitrate on the Optimum disc is 2465kbps DTS-HD MA, while the Criterions is 3761kbps DTS-HD MA.

Optimum is 16-bit, Criterion 24.

[kpkelley]

Originally Posted by Jeff Kleist

Optimum is 16-bit, Criterion 24.

Ok. How about Terminator 2. The Japanese geneon release has a 24-bit DTS-HD MA 5.1 track at 3595kbps, while the Skynet Edition has a 24-bit DTS-HD MA 5.1 track at 4046kbps.

Geneon
Skynet

[PeterTHX]

Originally Posted by BozQ

Dolby TrueHD is very capable of compressing 24-bit LPCM too.
And there have been TrueHD tracks in 24-bit too.

Pretty much all of Paramount's titles are 24-bit TrueHD.

Originally Posted by kpkelley

Ok. How about Terminator 2. The Japanese geneon release has a 24-bit DTS-HD MA 5.1 track at 3595kbps, while the Skynet Edition has a 24-bit DTS-HD MA 5.1 track at 4046kbps.

Skynet is ES (6.1) encoded.

[ClaytonMG]

Originally Posted by kpkelley

Ok. How about Terminator 2. The Japanese geneon release has a 24-bit DTS-HD MA 5.1 track at 3595kbps, while the Skynet Edition has a 24-bit DTS-HD MA 5.1 track at 4046kbps.

Geneon
Skynet

Isn't the Japanese version Dolby TrueHD, not DTS-HD MA?

[kpkelley]

Originally Posted by ClaytonMG

Isn't the Japanese version Dolby TrueHD, not DTS-HD MA?

Yup, my bad.


The only other example I could think of was the Artificial Eye release of Chungking Express vs. the Criterion release, but I can't find any technical specifications on the artificial eye release.

It still begs the question why the codec was able to compress the japanese track on Full Metal Alchemist significantly more than the english track. While his solution way not have been possible, his criticism is still valid as the lower maximum bit-rate would indicate a less dynamic audio presentation than the dubbed language.

[ClaytonMG]

Originally Posted by kpkelley

Yup, my bad.


The only other example I could think of was the Artificial Eye release of Chungking Express vs. the Criterion release, but I can't find any technical specifications on the artificial eye release.

It still begs the question why the codec was able to compress the japanese track on Full Metal Alchemist significantly more than the english track. While his solution way not have been possible, his criticism is still valid as the lower maximum bit-rate would indicate a less dynamic audio presentation than the dubbed language.

I think it might be due to the Japanese track being 16 bit.

[BozQ]

Originally Posted by PeterTHX

Pretty much all of Paramount's titles are 24-bit TrueHD.

They were. I think it's DTS-HD now.
Disney went from LPCM to TrueHD to DTS-HD as well.

The only studio to use TrueHD for most of their release is Warner Bros. And in 16-bit. =\

Originally Posted by kpkelley

It still begs the question why the codec was able to compress the japanese track on Full Metal Alchemist significantly more than the english track. While his solution way not have been possible, his criticism is still valid as the lower maximum bit-rate would indicate a less dynamic audio presentation than the dubbed language.

Don't be too obsessed with the bitrate numbers.
(A guess here)
It could be the Japanese track is in its original 16-bit form. But when the English dubbed dialogue, it's recorded in 24-bit, and finally mixed into the soundtrack in 24-bit. Therefore, resulting in a larger filesize.

But like I said, there's no need to get upset over different bitrate values.

[PeterTHX]

Originally Posted by BozQ

They were. I think it's DTS-HD now.
Disney went from LPCM to TrueHD to DTS-HD as well.

Paramount is title by title.

[BozQ]

Originally Posted by PeterTHX

Paramount is title by title.

Yeah. I just noticed it with Star Trek. Oh well. No biggie to me.
Important thing to note is, Dolby TrueHD 24-bit is possible.