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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: F.O.Bean on February 09, 2013, 11:19:07 PM

Title: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: F.O.Bean on February 09, 2013, 11:19:07 PM
I recorded Dopapod last nite, and didnt bother getting a patch in my 2nd M10. Well, after the show, Luke gave me the 2/8 PBurgh SBD on a SD Card of mine, and it stays aligned for about 15-20 mins and then goes out of sync :9 :'(  If anyone can walk me thru what exactly to do or just wants to do it instead of me, please shoot me a PM or post in this thread :)

Thanks in advance,
Bean
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: flipp on February 09, 2013, 11:57:39 PM
I am not familiar with Wavelab so don't know how different v5 and v6 are so the following may be spot on or completely different. The ts reference section has a tutorial for matrixing two sources in Wavelab5 (http://taperssection.com/reference/pdf/Wavelab5Matrix_MikeB.pdf).
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: F.O.Bean on February 10, 2013, 12:02:28 AM
I am not familiar with Wavelab so don't know how different v5 and v6 are so the following may be spot on or completely different. The ts reference section has a tutorial for matrixing two sources in Wavelab5 (http://taperssection.com/reference/pdf/Wavelab5Matrix_MikeB.pdf).

Oh my god, THANK YOU THANK YOU THANK YOU!!!! I looked everywhere for that :)

The only difference I know is that WL 6 can handle files UP TO 4GB ;D
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: Marshall7 on February 10, 2013, 05:45:33 AM
Nice find, flipp!
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: raymonda on February 10, 2013, 10:47:25 AM
I am not familiar with Wavelab so don't know how different v5 and v6 are so the following may be spot on or completely different. The ts reference section has a tutorial for matrixing two sources in Wavelab5 (http://taperssection.com/reference/pdf/Wavelab5Matrix_MikeB.pdf).

That tutorial does not discuss time stretch but rather syncing, which does not solve the question of timing issues. I've found that if there is drift you may need to cut the files up into smaller segments and may even need to remove very small segments of the file if the problem occurs during a song.

I've never really figured out how to use the time stretch, which would be really useful for analog sources. This is something I need to learn. anyone have a reference or answer?
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: flipp on February 10, 2013, 10:57:01 AM
There is a little discussion about that in the Mixing / Syncing Two or More Sources section of README1st! Links to frequently asked about topics... (http://taperssection.com/index.php?topic=117279.0) stickied to this section of ts.

note there is also a link to the Wavelab instructions there which Brian had the foresight to make a pdf file of since Fatah Ruark's original site is no longer available; other than poking around some of the links in that sticky I got nothin
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: raymonda on February 10, 2013, 11:19:16 AM
Excellent.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: todd e on February 21, 2013, 11:12:57 AM
i'm more than willing to take a stab too, if the FAQ doesnt help.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: hi and lo on February 21, 2013, 03:31:01 PM
I am not familiar with Wavelab so don't know how different v5 and v6 are so the following may be spot on or completely different. The ts reference section has a tutorial for matrixing two sources in Wavelab5 (http://taperssection.com/reference/pdf/Wavelab5Matrix_MikeB.pdf).

That tutorial does not discuss time stretch but rather syncing, which does not solve the question of timing issues. I've found that if there is drift you may need to cut the files up into smaller segments and may even need to remove very small segments of the file if the problem occurs during a song.

I've never really figured out how to use the time stretch, which would be really useful for analog sources. This is something I need to learn. anyone have a reference or answer?

You're not alone. I've found my success rate in using the time-strech function to be < 10% (and that's being generous) and the issue is that each time-stretch operation can require 20-40 minutes or longer. I don't believe that WL6 has much in the way of support for newer hardware (i.e. quad-core processors), so it's possible this operation runs much quicker on a new version, but it's slow as heck in WL6.

Anyways... what usually occurs is that it takes me 4-5 tries, at least, to get the right amount of stretch. I probably just suck at math (I do) because I am seemingly off every time and it turns into a routine of trial-and-error.

And then there is the changes in drift over time as you mention. I've seen plenty of recordings lined up perfectly at the beginning and end, but seemingly very far apart in the middle. The rate of a word clock is not an absolute constant and it's definitely possible to see large variations in drift over seemingly short time-segments. When this happens, the only option is to start chopping up one of the files and sync in small portions. bleck.

Quite frankly, I don't think any FAQ or Guide is going to help anyone attempting this process and fair warning... if you are going to attempt this be prepared to spend a lot of hours trying to get it right with the possibility that the only solution is the 'chop' method.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: F.O.Bean on February 21, 2013, 03:57:39 PM
I did the chop method recently, and IMO! It came out great, but it's not an easy/quick thing at all!
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: microburst on February 21, 2013, 09:08:05 PM
I've been working on time stretching a SBD source of the Joe Russo's Almost Dead show from Brooklyn Bowl with my audience pairs now for several weeks.  Both the SBD and my mics were recorded on a 744T but I was synched to the V3's clock and recorded at different bit and sample rates than the SBD that Bill Mulvey recorded.  This has been a monumentally frustrating task, one that I likely will not pursue again if and when I ever complete getting this done to my satisfaction.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: tgakidis on February 22, 2013, 03:23:50 PM
I've been working on time stretching a SBD source of the Joe Russo's Almost Dead show from Brooklyn Bowl with my audience pairs now for several weeks.  Both the SBD and my mics were recorded on a 744T but I was synched to the V3's clock and recorded at different bit and sample rates than the SBD that Bill Mulvey recorded.  This has been a monumentally frustrating task, one that I likely will not pursue again if and when I ever complete getting this done to my satisfaction.

I use Sony Vegas to stretch and it's a snap.  Send me the files and i will sink them up for you.  PM me if interested Eric.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: microburst on February 22, 2013, 05:59:18 PM
Sweet ted, seeing the ringers tonight but tomorrow i'll try to send em down...have a dropbox account?
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: tgakidis on February 23, 2013, 05:58:18 AM
Sweet ted, seeing the ringers tonight but tomorrow i'll try to send em down...have a dropbox account?

Yeah, hit me up at tgakidis@gmail.com
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: microburst on February 23, 2013, 07:22:14 AM
Sweet ted, seeing the ringers tonight but tomorrow i'll try to send em down...have a dropbox account?

Yeah, hit me up at tgakidis@gmail.com

Sent ya a an e-mail Ted.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: tim in jersey on February 23, 2013, 03:26:16 PM
I use Sony Vegas to stretch and it's a snap.  Send me the files and i will sink them up for you.  PM me if interested Eric.

Ditto.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: stevetoney on February 28, 2013, 07:52:42 AM
Ted, when you use Vegas to do the stretch, do the two files typically line up throughout or is there any mid-file mismatch?  If there's a mismatch, how is it to correct the mid-file drift using Vegas?  (I'm not a Vegas user, but I'd think it might get a bit hairy if there's not consistent straight line drift between the two sources.)

FWIW, I've had experiences both ways, where I'll stretch a file and it synchs well with the file I'm trying to match, but then I've had some where they don't line up great in the middle, even if they do line up at the beginning and the end.

In either case, when they don't match up, you need to line the tracks up so they're synched at time = 0 and then choose one or the other of the tracks to 'massage' all the way to the end of the set to get them paralleled with each other. 

For those of us that don't have Vegas, you can do this in the multi-track view of your DAW one of two ways that I know of.  You can try to stretch/shink small portions of the second track as you progress along the timeline of the show so that it matches the first track from t = 0.  Personally, I find this method to be a complete PITA and it never works right for me anyway. 

My preference is simply to delete tiny portions of the second file a tiny portion at a time along the track, starting at t = 0.  You can do this a song at a time or you can do a complete set at a time, as long as you build each master file starting from t = 0 with both files synched and keep them matched started from t = 0.  As long as you zoom way in and you only delete tiny portions on the second track, you can't hear the deletes...especially on a mixdown.  It's easy to keep the tracks lined up like this.  (hint: save often!)

I don't find it to be particularly difficult or really all that time consuming to synch two tracks when I use the second method (a couple hours for a show).  The key is, when you're lining up the tracks, to zoom in enough so you're focusing on individual notes along the timeline of the performance and make sure the two tracks are never more than a millsecond or so apart from each other, otherwise you'll hear the time delay between the two tracks as being overly reverb-y or echo-y on your mixdown master.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: tgakidis on February 28, 2013, 08:31:33 AM
I have never experienced a "mid file" drift.  I line up a high peak in the begining and stretch to line up the high peak at the end. Doesn't take long at all, maybe 5 minutes.  I then adjust levels of each source to my taste then vegas can render it down to 16/44.  Typical mix time with rendering is less then a 1/2 hour.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: stevetoney on February 28, 2013, 09:04:17 AM
I have never experienced a "mid file" drift.  I line up a high peak in the begining and stretch to line up the high peak at the end. Doesn't take long at all, maybe 5 minutes.  I then adjust levels of each source to my taste then vegas can render it down to 16/44.  Typical mix time with rendering is less then a 1/2 hour.

Damn.  That's freakin' sweet.  Hmmm, where did I put my old 'try it out' copy of Vegas anyhow?
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: Fatah Ruark (aka MIKE B) on February 28, 2013, 11:04:06 AM
The way I do this is to line up the beginning of the recording, then go to the end.

Try and find a spot to match it up TOWARDS the end. Doesn't have to be exactly at the end.

Then measure the time between the two points. To do this I highlight from the shorter sources peak to the longer sources peak.

On the lower right of the screen it will tell you how much time you selected.

Stretch the shorter source by that amount.

Doesn't work 100% of the time, but I usually can get it by the second or third attempt.

I have solved this problem by a second method which is much easier. I bought a DR-680. :P

I'd make another tutorial, but I don't use that method anymore since my two (or 3) sources are always in sync.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: hi and lo on March 01, 2013, 03:25:47 PM
I'd like to know why Vegas can do a timestrech operation in 5 minutes but Wavelab can take an hour or longer.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: nicegrin on July 03, 2013, 04:58:11 PM
It´s quite straight forward as Mike B already described...

If you are using the same two recorders often enough you just benefit alot from calculating the stretchfactor just once and then just apply it every time.

The stretch factor between my two m10s for example is 1.00000245144 which is about 10 times better than between my 10s and my Edirol R09 HR! :p

Applying this stretch factor the difference is usually less then 0.001 seconds at any time for a 2 hour recording!

Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: Gutbucket on July 03, 2013, 06:10:07 PM
The way I do this is to line up the beginning of the recording, then go to the end.

Try and find a spot to match it up TOWARDS the end. Doesn't have to be exactly at the end.

Then measure the time between the two points. To do this I highlight from the shorter sources peak to the longer sources peak.

On the lower right of the screen it will tell you how much time you selected.

Stretch the shorter source by that amount.

Doesn't work 100% of the time, but I usually can get it by the second or third attempt.

I have solved this problem by a second method which is much easier. I bought a DR-680. :P

I'd make another tutorial, but I don't use that method anymore since my two (or 3) sources are always in sync.

Works similarly in Samplitude:
1) Find appropriate peaks near the beginning and ends of the file.
2) Measure the time or samples between those points in the reference (non-stretched file).
3) Select the same range in the file to be stretched.
4) Use the time or sample value from the reference file to modify the object properties of the one to be adjusted.


It probably doesn’t make much difference since the overall stretch percentage is pretty small, but simply as a best practice thing, it’s technically better and less artifact prone to ‘shrink’ the longer running file rather than ‘stretch’ the shorter running one, regardless of what editor is used to do it.
Title: Re: Matrix Time Stretch walk-thru for WaveLab 6.0............
Post by: beatkilla on July 04, 2013, 11:04:55 AM
It's really easy in Sony Vegas but for best quality be sure to set

Project Properties audio tab to BEST pitch and time stretching

and very important to change in the timeline on the audio event to be stretched,Right CLick and go in to properties tab and change stretch method to Elastique PRO.Otherwise it defaults to classic A03.