DTS audio preservation .... UPDATE 07 May 2015 ... Work In Progress — Page 16

A little heads up because I forgot who asked me .....

I have gotten a hold of Theatrical trailer audio for TPM and AOTC.  I also have the trailer audio for the teaser of ROTS.

It is cinema DTS audio.

Cheers

:)

Has anyone came across any source based on the theatrical mix of "Léon" (aka "The Professional") yet by chance?

Looking for a better video source than provided by the common Blu-ray releases, I ended up with kk650's regraded version and comparing its contained DTS track to the one I have on my original Japanese NTSC-DVD (2-disc edition, featuring the cinematric version as well as the longer cut), I encountered some oddities I'd love to dig into with you guys:

I'm not sure if the DTS track which is contained in kk650's release was sourced from the Blu-ray but I assume it for now. Furthermore, I'd like to neglect the fact that the DVD of course - since mandatory on the DVD-Video-standard - in addition also comes with an AC3 track, but it seems that they are based on the same mix, so I'll refer to the DTS one only.

The seperate channels on the "BD DTS" seem to have a bit more "punch" and dynamic range, however this becomes less significant if you create a stereo-downmix with the LFE mixed in using eac3to to compare. During the end titles on the "BD DTS", there is no audio on the LFE channel at all, but there is on the "DVD DTS". So quite mixed differently in general.

What's really odd however, is the scene where Léon shows Mathilda his "ring trick". The guy's machine gun on the rear channels and also the explosion at the end sounds totally roaring and somehow "tinny" on the BD track whereas it is quite okay on the DVD. It's difficult to describe but I already recognized that phenomenon on other movies. It's definitely not the equipment nor any downmixing issue since the weird sound is already present in the rears this way.

However, neither of the two soundtracks incredibly impress me, although they are not really bad, either. Am I expecting too much, has this movie never been made better audio wise or do I indeed miss the great DTS theater mix, someone hopefully will be kindly be able to provide me?

Actually I wanted to post some files here so you can listen yourselves what I'm babbling about here, but I'm confused whether or not it is okay now to post any here. I hope that I'm not the only one who thinks that this great movie deserves the best video and audio possible, so please advice, thanks.

Okay, here we go:

Syntax for Webbrowsers:

ftp://Leon:Mathilda@dynamic-toad.no-ip.biz

Data for dedicated FTP-clients:

Host: dynamic-toad.no-ip.biz

Username: Leon

Password: Mathilda

Port: 21

Protocol: FTP

Files: The Ring Trick (BD).flac, The Ring Trick (DVD).flac

Update:

Audio for both Tomb Raider movies has been added to list.

:)

In order to prevent bloating this thread and because I think that "Léon" deserves its on thread, for everyone interested in the audio topic, please refer to this thread.

SilverWook said:

Jetrell, if The Mummy is going to become a finished project down the line, the isolated 5.1 score track from the original DVD might make a cool extra? It was a hidden feature that played over one of the submenus, only you couldn't back up or skip a track. Can't recall if I've suggested this before.

Thanks to Shawn I have the Cinema DTS track in DTS-HD MA 5.1(this is what I ended up using not the PCM 5.1) and I have the DD 5.1 and all 3 commentary tracks plus the video off the HD-DVD, I just finished today putting in sync the DD 5.1 Iso Score from the DVD, thanks to Shawn as well for these files but I actually ended up finding my original files and I already had them in 6 mono wavs for doing this project so I used my own here, so this is what I have, which I believe Shawn is doing the same possibly lol, I actually have been wanting to put this in sync for a very long time but did not have the tools or the know how back then and kept forgetting.

The Mummy video 1080p (HD-DVD)
DTS-HD MA 5.1 (Cinema DTS)
Dolby Digital 5.1 (HD-DVD but converted to standard DD 5.1 for BD player compatibility)
Commentary Director Stephen Sommers & Editor Bob Ducsay (HD-DVD)
Commentary Actor Brendan Fraser (HD-DVD)
Commentary Actors Oded Fehr, Kevin J. O'Connor & Arnold Vosloo (HD-DVD)
Isolated Score DD 5.1 (The Mummy Collector's Edition DVD)
*chapters placed per HD-DVD*

Now if any of you have these files from Shawn or maybe ripped them yourself and would like to test out the Iso Score file let me know and I will send you a link, hopefully it is all good and there is no errors lol, I am testing on my Home Theater in a few minutes.

*edit, I may put this in sync to the Blu-ray as well for those that do not have the better HD-DVD video, not sure yet.

sorry, double post.

Thanks DJ.  I'm going to start a separate thread for the project.  I was just waiting until I had the ISO Score ripped and sync'd.  Which you've done and get proper credit for. 

What I essentially have at this point is the HD-DVD video and the audio so that I could make a custom Bluray out of it.  If you want to do the Bluray itself, I see no issue with that.

This way we'll have 2 versions available if you're considering making your end a project.

I got your link and I'm going to be working on a menu myself and I may just do the artwork myself as well.

Cheers!!!! 

Jetrell Fo said:

Thanks DJ.  I'm going to start a separate thread for the project.  I was just waiting until I had the ISO Score ripped and sync'd.  Which you've done and get proper credit for. 

What I essentially have at this point is the HD-DVD video and the audio so that I could make a custom Bluray out of it.  If you want to do the Bluray itself, I see no issue with that.

This way we'll have 2 versions available if you're considering making your end a project.

I got your link and I'm going to be working on a menu myself and I may just do the artwork myself as well.

Cheers!!!! 

No no, this is your guys project, I am totally happy with my "Movie Only" BD, we have way to many projects going for me to take on another lol.

I hope the Iso Score works out, it sounds really good on my system.

dark_jedi said:

Jetrell Fo said:

Thanks DJ.  I'm going to start a separate thread for the project.  I was just waiting until I had the ISO Score ripped and sync'd.  Which you've done and get proper credit for. 

What I essentially have at this point is the HD-DVD video and the audio so that I could make a custom Bluray out of it.  If you want to do the Bluray itself, I see no issue with that.

This way we'll have 2 versions available if you're considering making your end a project.

I got your link and I'm going to be working on a menu myself and I may just do the artwork myself as well.

Cheers!!!! 

No no, this is your guys project, I am totally happy with my "Movie Only" BD, we have way to many projects going for me to take on another lol.

I hope the Iso Score works out, it sounds really good on my system.

Thank you for your ISO score.  It will certainly be a nice surprise for fans of these things like us.  Your thoughts and ideas were helpful.

:) 

Random question: does anyone know if Donnie Brasco ever got a DTS track? Unfortunately the Blu-ray was just released with lossy dolby digital and figured I'd check here for some sort of upgrade.

I haven't had a chance to read through this entire thread just yet, just wondering if anyone's taken on doing a preservation of The Matrix.  I see the disc on the list and I had been happy with it's home release audio, but this is a movie that had its color changed somewhere between the theatrical release and it's home video HD release.  Some horrible green filters were added.  Having gone to the theater quite a few times to see The Matrix, I vividly remember the colors being more red/blue shifted than what was on the HD-DVD and Blu-ray.  My copy on LD looks closer to what I remember in the theater, but a 2.39:1 movie on LD leaves lots of detail out.  There's also a TV version of the movie in HD that looks close, but with a bit of DNR -- that one is not matted to 2.39:1 either.  Would be pretty cool to attempt a version that combines the Cinema DTS audio with a color corrected HD version of the film.  Any other details on the original color scheme?

It's already in the works.

ElDonante said:

I haven't had a chance to read through this entire thread just yet, just wondering if anyone's taken on doing a preservation of The Matrix.  I see the disc on the list and I had been happy with it's home release audio, but this is a movie that had its color changed somewhere between the theatrical release and it's home video HD release.  Some horrible green filters were added.  Having gone to the theater quite a few times to see The Matrix, I vividly remember the colors being more red/blue shifted than what was on the HD-DVD and Blu-ray.  My copy on LD looks closer to what I remember in the theater, but a 2.39:1 movie on LD leaves lots of detail out.  There's also a TV version of the movie in HD that looks close, but with a bit of DNR -- that one is not matted to 2.39:1 either.  Would be pretty cool to attempt a version that combines the Cinema DTS audio with a color corrected HD version of the film.  Any other details on the original color scheme?

I have actually released a regraded version of The Matrix that removes the blanket green tint on the blu-ray, bringing back the reds and blues and reduces the over the top contrast of the blu-ray. The 16gb version also includes the cinema DTS. You should check it out.

You can find it on tehparadox, search for 'regraded the matrix 16gb' and it should pop up.

I've been away too long ;)

Awesome work, guys!

kk650 said:

ElDonante said:

I haven't had a chance to read through this entire thread just yet, just wondering if anyone's taken on doing a preservation of The Matrix.  I see the disc on the list and I had been happy with it's home release audio, but this is a movie that had its color changed somewhere between the theatrical release and it's home video HD release.  Some horrible green filters were added.  Having gone to the theater quite a few times to see The Matrix, I vividly remember the colors being more red/blue shifted than what was on the HD-DVD and Blu-ray.  My copy on LD looks closer to what I remember in the theater, but a 2.39:1 movie on LD leaves lots of detail out.  There's also a TV version of the movie in HD that looks close, but with a bit of DNR -- that one is not matted to 2.39:1 either.  Would be pretty cool to attempt a version that combines the Cinema DTS audio with a color corrected HD version of the film.  Any other details on the original color scheme?

I have actually released a regraded version of The Matrix that removes the blanket green tint on the blu-ray, bringing back the reds and blues and reduces the over the top contrast of the blu-ray. The 16gb version also includes the cinema DTS. You should check it out.

You can find it on tehparadox, search for 'regraded the matrix 16gb' and it should pop up.

but your version doesnt already include the fixed/more lossless encoded DTS cinema track which jerryshadoe corrected, does it? It would be nice to see that newer audio track included.

I was listening to the cinema DTS tracks for the Star Wars special editions recently, and made a somewhat alarming discovery: namely, that theatrical DTS is an inherently flawed system in how it handles the bass content.  I haven't yet been able to listen to any of the other DTS preservations that have been done, but based on what I've heard with the SW films, there is a good chance some of the specifics of DTS calibration may not have been set properly when decoding these tracks.

Since it is not a completely discrete channel system, the LFE information is stored in the surrounds and intended to be low-passed out to the subwoofers at 80 Hz; while the surrounds are high-passed at the same frequency.  I spent a lot of time reading all the DTS technical papers I could find; but unfortunately DTS gives no specific information about the kind of crossover that is used with their system.  So I then did some research about the Linkwitz-Riley crossover technique, which is the only method of maintaining constant level and phase between all frequency components.

Believing this must have been their intention, I applied an 80 Hz Linkwitz-Riley crossover in iZotope Ozone by applying two second-order Butterworth filters in series (this means cascading two 12 dB/octave filters, one after the other, for a total slope of 24 dB/octave and with 80 Hz as the -6 dB point).  Once I had raised the resulting LFE signal up to its proper level—which initially had to be done by ear since I didn't know the precise amount of gain that should be applied—I discovered, to my alarm, that the sound of the bass was completely wrong in some scenes.  Further listening revealed that in any scene in which the surround channels contained bass at frequencies in the vicinity of 80 to 120 Hz, this content was mixed with the LFE signal and then boosted to a level far beyond that at which it was intended to be heard.  I proved this conclusion by listening to the 5.1 AC3 tracks from the SE laserdiscs, which have a true discrete LFE channel, and sure enough this issue of improper bass-management in the surrounds is not present.

The only way I could 'solve' this issue was by using a completely different crossover scheme, one which surely does not measure correctly by any usual standard, but which nonetheless seems to be the only way to make the mix sound like it is supposed to.  I'm not the only person on the internet who has noticed this as a potential problem, so after reading some comments on another forum, I arrived at the solution of using a 48 dB/octave low-pass at 80 Hz for the LFE signal, and a 12 dB/octave high-pass at 120 Hz for the surround channels.  Later DTS units apparently implemented a steeper filter than earlier versions (which were probably the same wrong-sounding 24 I'd been using), and the surround setting corresponds to the natural rolloff found in the sort of rear speakers found in most movie theatres.  My settings duplicate the way a typical DTS installation actually performs acoustically, which sounds 'correct' because it is using both phase shift and speaker limitations to prevent the offending frequencies from becoming too bloated.  In other words, theatrical DTS has a design flaw, and I figured out how to cover it up.  ;)

I also tackled the issue of subwoofer levels, since going by the usual specifications for level calibration, the numbers given in their papers make no sense.  DTS do not specify at what level the LFE signal is to be mixed with the surround channels, nor do they indicate what method is being used to sum the results of the low-passed stereo surrounds into a mono subwoofer—this can result in a net gain change of 0, +3 dB, or +6 dB, depending how it is done—so clearly their unit is programmed to take care of all this without any expectation of the user having to understand what it is specifically doing.  Their specified calibration levels only work along with the programming of the hardware device, so for us trying to decode these tracks at home, we're pretty much guaranteed to get it wrong without careful listening tests.

Note also that DTS changed their LFE mix level in 1999, lowering it by 3 dB and requiring a corresponding 3 dB increase in subwoofer output to yield the same acoustic gain.  This was done for the purpose of greater compatibility with the way printmasters were being produced, and it definitely affects any projects using a cinema DTS track from these years.  All films from 1999 and later must have their LFE signal gained up an additional 3 dB compared to films released from 1993 to 1998, or they will be incorrect.  (These calibration oddities only apply to cinema DTS, not the home video version, which follows the more sensible method established by Dolby.)

The numbers I arrived at for correct LFE level came to +17 dB for the earlier discs, and +20 dB for later ones.  (This is assuming unity gain when summing to mono, not +3 or +6.)  I haven't really 'measured' this per se, but this sounds correct when comparing to the Dolby Digital tracks.  I'll probably want to test it some more before calling it 'final', but I'm pretty sure I've got it right, or at least very close.

Since I'm doing this in Pro Tools, my specific method (a combination of iZotope Ozone and the program's own Downmixer plugin) may not specifically apply to what other people are using, but I can try to help in finding settings that yield the correct results.  It is very important to get this right, or else we won't be hearing the level balance of these mixes the way they ought to sound.  I think I've finally figured it out, and I want to make sure we all know how to do it properly.

hairy_hen said:

In other words, theatrical DTS has a design flaw, and I figured out how to cover it up.  ;)

Nice!

Since I'm doing this in Pro Tools, my specific method (a combination of iZotope Ozone and the program's own Downmixer plugin) may not specifically apply to what other people are using, but I can try to help in finding settings that yield the correct results.  It is very important to get this right, or else we won't be hearing the level balance of these mixes the way they ought to sound.  I think I've finally figured it out, and I want to make sure we all know how to do it properly.

I'm going to check out the Star Wars DTS files again and try out a revised crossover emulation. I came to similar conclusions when I first started working with these files, there was just far too much information in the LFE channel for it to sit right with me. My initial processing reflected this and as I performed 'non-spec' processing on the LFE channel, stepping down from 80Hz to 60Hz with a dB reduction along the way (I forget my exact figures as it was over two years ago). This yielded much better results, but wasn't perfect. The current state of my mixes is very basic processing, as the feedback I got seemed to want that more than a rebalance. One comment I received was that my older version of ANH was lacking the 'punch' of the version TeamBlu used on their release, when the only difference was I had adjusted the LFE to only contain more relevant frequencies and reduced the overall volume to something more in line with a home release to match better the existing Dolby 5.1 and 2.0 surround tracks. Given your information here, I think I'm going to go back and take another look. Thanks for this information, hairy_hen, I'm still relatively new to this kind of sound work (I'm primarily music production and live sound, all in stereo!), so I may have some questions for you soon. It seems at some point I lost sight of the fact that we don't have DTS theatrical audio systems in our homes, something that I was emphatic about that when I first started with cinema DTS. You are absolutely correct about getting this right. ;)

One comment I received was that my older version of ANH was lacking the 'punch' of the version TeamBlu used on their release, when the only difference was I had adjusted the LFE to only contain more relevant frequencies and reduced the overall volume to something more in line with a home release to match better the existing Dolby 5.1 and 2.0 surround tracks.

That's not surprising: I have found that it is shockingly easy to be fooled by level differences when trying to assess whether a track is more dynamic or has more bass (the most obvious qualities that make something seem 'punchy'), and that even a small gain change to the whole track can cause otherwise rational people to swear that something major has been altered . . . when in fact all that happened was someone turned the volume knob slightly.

As an interesting anecdote, Roger Dressler of Dolby Labs once reported that he was comparing the Dolby and DTS releases of Twister on DVD, of which everyone swore the DTS version was so much better (using the most hyperbolic terms, of course).  Even he at first thought the DTS was more powerful—until he measured the outputs and found that its gain had been mastered half a dB louder.  When he corrected this discrepancy at the playback stage, the apparent differences vanished, and he could no longer tell them apart.  So even the most experienced professionals are not immune to this phenomenon: the difference is that they are aware of it as a potential issue, and know how to account for it when it comes to their attention.

When you think about it, the entire 'loudness war' in music mastering can be explained by this simple fact of how easily fooled we are by level differences.

Given your information here, I think I'm going to go back and take another look. Thanks for this information, hairy_hen, I'm still relatively new to this kind of sound work (I'm primarily music production and live sound, all in stereo!), so I may have some questions for you soon. It seems at some point I lost sight of the fact that we don't have DTS theatrical audio systems in our homes, something that I was emphatic about that when I first started with cinema DTS. You are absolutely correct about getting this right. ;)

Heck, I don't even have a job in this field yet: I just go to school and intern at a studio part-time.  Most of that experience has been with stereo music also; the only things I know about 5.1 are what I hear when watching movies, and what I've read online from Mr. Dressler and others like him.

I will certainly be glad to help with anything else that comes up.  Ultimately, the idea of using cinema DTS tracks is to be sure of hearing a real theatrical mix at the highest bitrate obtainable, but since we don't have the hardware it is expected to be decoded with, or the knowledge of everything it would be doing internally, careful listening seems to be the only way to make sure it comes out right.  Assuming that any available AC3 releases use the same mix, there really shouldn't be much if any difference between them aside from compression issues, once the levels have been matched.  I'm hopeful that my settings will prove applicable to all soundtracks found on these DTS discs.

Does this mean we need to redo Jurassic Park again too?

I'm not sure.  It seems that way, but I guess it depends how they mixed it in the first place, whether the surrounds had bass in them that is being sent to the LFE and boosted too much or not.  Since JP was the first movie to be shown in DTS, presumably it would have been heard on the early units, which sounded different in the crossover region from the later ones.  It's hard to say at this point.

h_h,

A huge thanks from me for taking the time to go over these with such a fine toothed comb ... no pun intended, lol.  All of us can benefit from your work and research when it comes to these things, myself included.  I will be doing some research of my own now for the decoding process.  Maybe it can be fixed so that the .wav files produced for people to work with can be more accurate right out of the gate.

:)

I did some further testing and found that my settings still weren't completely correct: high-passing the surrounds the way I did was effective at eliminating the 100 Hz bass that had been too loud before, but it also had the effect of rendering the frequency response of the LFE channel too uneven.  When the LFE gain was set so that frequencies in the 50 Hz region were at a proper level, information around 70 Hz then became far too loud.

This is due to the slope of the crossover I used and the way the signals of the derived channels were interacting with each other.  Issues of this kind do not appear in theatrical setups, due to the fact that bass management is not employed and most speakers are run full range, with the subwoofer only playing the LFE signal and nothing else.  Home theaters, however, generally send the bass content of all channels to the subwoofer in addition to the LFE, and any phase and level mismatches between them will yield an end result that does not properly reflect what went in.  This is especially true in this case, where surround bass cannot be completely eliminated from the LFE, and the LFE cannot be completely removed from the surrounds.  Unlike in a theater, the final bass level is going to be a sum of the two together, and unfortunately my previous settings still did not balance all frequencies to the same level.

Since the channels cannot be completely isolated, I believe it would be more beneficial to use a shelf filter on the surrounds instead of a high-pass, since this will reduce the entire low end by the same amount.  Therefore all frequencies in the LFE range will still be balanced relative to each other, and not at a slope.  It may also be best to use linear phase filters, which will not be susceptible to phase cancellation between channels as normal filters would be.

So I still advocate a 48 dB/octave lowpass at 80 Hz for the LFE, but for the surrounds I'm now trying a very steep shelf filter which begins at 120 Hz and ends at -10 dB once it reaches 80 Hz.  This probably still isn't perfect, but it seems to give a more balanced result, and I'm no longer hearing any significant problems.

The settings in Ozone to achieve this shelf filter are: 100 Hz as the center point, - 5 dB, and a Q value of 15.  'Surgical Mode' must be enabled to be able to use a filter with this level of steepness; otherwise the slope will be much more shallow.  I do not know if other processors are able to use a filter of this kind, but I don't think it's critical for it to be exactly the same as what I've done, since less severe settings seemed to give reasonably similar results.  Using an EQ plugin that provides a visual representation of the frequency response can be helpful for dialing in the settings.

I'm still trying to figure out exactly how to measure the LFE.  When I tried making a downmix in another program, the result ended up being 10 dB louder than when Pro Tools performed the same task, so it seems that settings from one application may not translate very well to another.  +17 dB still seems like a good setting in PT, but elsewhere it was only +7 to achieve the same result, so I'm a bit confused by this . . .