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Dolby Surround captured tracks - options
#1
You have a beautiful mixed stereo track encoded in Dolby Surround, ready to be captured and sync'ed with the latest BD which, of course, has the *wrong* audio track...

Now, there are few options to treat this track...
  1. capture the track in stereo, leave it "as is", untouched (apart eventual 44.1->48KHz conversion) and leave the task of decoding to the BD player/amplifier/PC software
  2. capture the track in stereo, decode it with a software decoder, then save the decoded output as uncompressed PCM/lossless compressed DTS-HD MA/lossy compressed DTS or AC3
  3. decode the stereo track with an hardware decoder, then capture the multichannel decoded output and save the resultĀ as uncompressed PCM/lossless compressed DTS-HD MA/lossy compressed DTS or AC3
why? Well, actually all Dolby Surround - better, ProLogic (I, II etc.) are on the same Dolby Digital chipset, and its quality is lower than ancient, vintage, Dolby Surround (ProLogic) dedicated decoders... also, software decoder seems to be not on the same level of hardware decoder...

So, option #3 seems to be a great alternative to the other two...

Opinions?
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#2
Its funny you posted this spoRv, I have been working on a project using this very train of thought. I usually prefer the first solution. Try to preserve the original track as close to the way it appears on the laserdisc (44 to 48 not withstanding). But much like you, I realized people are not listening to these tracks in Dolby Surround (Stereo) or Pro Logic anymore. Most modern Receivers/Pres/Pros don't have Surround or Pro Logic anymore. They have Pro Logic 2 or X or Z and DTS:Neo. Hell, the latest units that have Atmos have a up-mixing system called Dolby Surround that has little to nothing to do with the tradition Dolby Surround.

Anyway, I was working on a project using your third solution. Thinking people could hear a discrete representation of a Dolby Surround track. While my Alien project has 3 tracks (one PCM, two AC3), Blade Runner has 3 tracks (two PCM, one AC3), my Road Warrior project just has the 1 PCM track (Jonno's LD cap). So there is room for experimentation. I thought I could pull the 5.1 from the BD or even better, I could up-mix the PCM.

A few years ago when I had more money I started collection old Dolby Surround (DS) hardware decoders to listen to DS in its "purest" form. I wondered if I could record the output and add it to a project. Recording 5 RCA plus (essential 5 PCM tracks) is hard but I think I found a solution that might work. So I was thinking how about a track through a Fosgate Model 5 in 70mm mode or a Shure HTs (Disclord's old favorite) or the newfangled Involve audio? Much like you, I think its a interesting, fun project.
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#3
PDB, now that I know you have a Shure HTS (I bet the 5300), I'm starting to hate you... Wink Smile Tongue

Well, I thought to do that, capture the output from a real, "old school" Dolby Surround (ProLogic) decoder, and convert the channels as discrete multichannel track; I'm thinking to do it with my poor (in comparison to your hardware) Pioneer SP-07D, but now that I discovered you have far better equipment, it's your turn to experiment... Wink

Indeed, I'm thinking to buy a new PCI sound card with analog multichannel inputs, but it's quite difficult - if not impossible - to find out one at fair price with RCA inputs; I know, I can use the 6.3mm jacks with jacks->RCA cables... I'm dreaming about a Lynx TWO-A, but it will remain only a dream...

Of course, as DS is only 4 channels, you could always capture the signal with a double capture (ch1+2 first, then ch3+4); double time, but no further equipments needed!
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#4
Sadly its an older HTS 5000. Like I said I have idea but I'm not 100% sure it will work. So I don't want to discourage your own tests spoRv. Not sure I will succeed.
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#5
HTS 5000 is not bad, AFAIR... also, more tests = more results... Big Grin

I thought to do this:
capture video and audio ch1+2 with VirtualDub (cap1)
capture video and audio ch3+4 with VirtualDub (cap2)
put in synch cap1 & cap2 (cap1sync & cap2sync)
extract ch1+2 from cap1sync
extract ch2+3 from cap2sync
result is L+R+C+S
copy S to S2
extract LFE from L+R (and maybe from C, or from the whole)
put the L+R+C+S+S2+LFE in a single multichannel track

easy, uh? Big Grin
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#6
(2015-06-04, 05:24 PM)spoRv Wrote: HTS 5000 is not bad, AFAIR... also, more tests = more results... Big Grin

......
easy, uh? Big Grin

That is the opposite of easy and exactly what I wanted to avoid Big Grin
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#7
...now you know why I wrote "it's your turn to experiment!" Big Grin Big Grin Big Grin

Well, maybe someone else has done it before... or, we'll going on with our experiments, release few projects with such tracks, to discover in few years that some studios have done the same - probably stealing our idea!!! Wink

To the studios: you are more than welcome to use our techniques; but some credits are deserved, though! Wink
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#8
(2015-06-04, 05:24 PM)spoRv Wrote: HTS 5000 is not bad, AFAIR... also, more tests = more results... Big Grin

I thought to do this:
capture video and audio ch1+2 with VirtualDub (cap1)
capture video and audio ch3+4 with VirtualDub (cap2)
put in synch cap1 & cap2 (cap1sync & cap2sync)
extract ch1+2 from cap1sync
extract ch2+3 from cap2sync
result is L+R+C+S
copy S to S2
extract LFE from L+R (and maybe from C, or from the whole)
put the L+R+C+S+S2+LFE in a single multichannel track

easy, uh? Big Grin

This is actually a pretty good ideaWink

Yes, I would say that this is easy, just a little time-consuming. And most of "us" that work on various projects know, that this is usually the biggest problem - not enough time, LOL

That being said, once anyone has some "tests" conducted, I would love to see a sample because theory does not always equal reality and I'm wondering if this would actually sound right...
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#9
(2015-06-04, 11:18 PM)jerryshadoe Wrote: ...and I'm wondering if this would actually sound right...

How did you dare to suppose it would not sound right?!? Tongue Tongue Tongue

It WILL sound right; it should be proved, however, if this is better than a new, modern, Dolby-"I-do-it-all,bad-but-I-do" decoder!
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#10
The fact that it "should" sound better captured this way versus the new "dolby-decode-it-all-bad-but-it-does," I am NOT arguing... however, I wonder if it will be "right" to change it to a 5.1? Since the original is made 4.0, shouldn't the "final" audio output be the same?
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