Time stretching audio

[SMS]

I'm doing a project where I need to time stretch some drum tracks. These are fills or short sections that are a little rushed, so I need to stretch all the drum tracks the same amount so they land in the right place.

I cut the soundbite at the beginning of the bar and right at the end of the hit on "1", then stretch that until the hit lands on 1. I just do it visually, using the 'hand' cursor to stretch the soundbite until the hit lines up with the grid. Easy peasy for a single track, but I'd like to be able to do this to multiple tracks at once. As far as I can tell the only way to do that is with the Region>Scale Time... commmand, but then I need to know exactly where the end of the bite needs to be, or the correct percentage to scale by.

I want to make sure all the tracks are stretched exactly the same. You'd think that if multiple tracks are selected, the 'hand stretch' would apply to all selected bites, but no. Also doesn't seem like I can get the stretch to snap to the grid, which would also insure all tracks get stretched the same.

Thanks


Spence

[davidh]

Not near my computers at the moment, but I'm pretty sure you can do this by creating a group comprising all your drum tracks. Make sure that 'edge edit' is enabled in the group's settings. Then when you edge edit (or stretch) any track within your drum group, all tracks in the group should be affected.

[SMS]

Oddly, that group setting doesn't apply to 'edge-stretching'.

[terrybritton]

If worse comes to worse and DP cannot handle this, export the stems and try using the latest version of Audacity.

Just was notified that Audacity has updated from version 2.1.2 to 2.1.3, and it has added a high quality option to its time-stretch/pitch-shift algorithm as per this from the changelog:

SBSMS (higher quality but slower) option on Change Tempo / Change Pitch effects.


Here is the full change log:

Changes since version 2.1.2: 

Changes and Improvements:
   
 * Interface:  
   * (macOS) Support for horizontal scroll on Magic Mouse / Trackpad and for
     Trackpad pinch/expand zoom gesture.
   * Pinned option on waveform so waveform moves and recording/playing head
     stays still.
   * Timer Record options to save/export/exit after recording.
   * Scrub Ruler and optional Scrub Toolbar.
   * New shortcuts ALT+RIGHT and ALT+LEFT (move to labels without editing). 
   
 * Effects:
   * Effects no longer grayed out when paused.
   * New Distortion effect (replaces Leveller).
   * SBSMS (higher quality but slower) option on Change Tempo / Change Pitch 
     effects.
   * New Rhythm Track generator (replaces Click Track). 
   * New Generator for Sample Data Import.
   * Nyquist effects now significantly faster.
   
 * Other Changes:   
   * Upgraded the PortAudio library to v19 rev r1966.  This gives Audacity 
     Windows 10 support.
   * (macOS) Audacity.app now has its resources inside it rather than in a
     separate folder, so installation to /Applications/ is cleaner.
   * (macOS) Audacity 2.1.3 provides partial support for Sierra. Details at 
    http://wiki.audacityteam.org/wiki/Parti ... a_in_2.1.3

http://www.audacityteam.org/download/

Terry

[mikehalloran]

Good news and bad:

It's easy enough to line your tracks up if you zoom to a higher resolution in DP. That's the good news.

The bad is that DP's time stretch and compression are limited before you start hearing artifacts. Percussion should be less noticeable—that's good

More good news: MOTU announced at NAMM that this function was getting a nice update. Those who heard it were impressed. The bad news is that it's not been released yet.

There are many third party tools that do this very well including Melodyne 4 and IRCAM Time Stretch, available as its own plugin and bundled with MachFive3, UVI Falcon and others.

There are other 3rd party plugs whose quality ranges from ok/on par with DP to very good. I haven't heard that any are as good as Melodyne or IRCAM, however.

I'd try DP first. Zoom in and see if you can make it work.

[SMS]

Thanks for the replies.

In DP, drum tracks and also upright Bass parts are stretching just fine with no audible artifacts. These are small (around 105% at the most) stretches, and even stretching the drum tracks individually at lower edit resolutions seems to be OK, so I don't need to use external apps. I was just looking for a quicker, more 'guaranteed successful' way to accomplish this in DP.

Speaking of external apps, for those times when I need to do a significant time or pitch change on complex material, the IRCAM algorithm in Machfive does an amazing job. Check out the YouTube videos on this if you haven't seen it.

[mikehalloran]

I usually find that anything outside the 90%–110% range is pushing it in DP.

Yes, MachFive3 is quite good for this. I also have Melodyne Studio 4 but don't use it for that. Well, not yet but I hear that's also quite good.

[SMS]

Luckily I haven't had to deal with tracks that rush or drag by more than 10%!

[mike_o]

you can get a time-stretch to snap to grid by holding the command key while using the hand tool, I'm pretty sure its the command key, but it might be option.

I snap to grid on time-stretch all the time, it's there.

[Don T]

Hello,
OK I just have to be "that guy" again.
This problem is why I also have PT running on my rig. What you are trying to do is incredibly easy and transparent using elastic audio / warp in ProTools.
I love DP and it is my main DAW but I believe in using the best tool for any job which means there are things I do in other DAWs as well.

[EMRR]

Love to see a useful update in DP. I gave up on stretching multi-miked anything in DP, drums always develop audible phasing problems (phase shifter stomp box sound) between tracks, no matter how small or large the stretch.

[Morpheo]

Hello,
OK I just have to be "that guy" again.
This problem is why I also have PT running on my rig. What you are trying to do is incredibly easy and transparent using elastic audio / warp in ProTools.

Besides, the resulting sound quality in DP in always more than questionable, even with very small amount of stretching. I've done this countless times in Pro Tools and it's indeed so much easier. Being able to do it on a group of tracks simultaneously would be a very welcome addition to DP.

[buzzsmith]

Hoping the eventual update will incorporate a useable time stretching algorithm!

Buzzy


Sent from my iPad using Tapatalk

[Klaus]

Hi all
I'm working on a live album and one song is played pretty well, but speeds up gradually…
Is there a plug or a standalone app that you can 'input' a time / speed curve ?
Thanks for hints and
best regards to everybody

Klaus

[bayswater]

Hi all
I'm working on a live album and one song is played pretty well, but speeds up gradually…
Is there a plug or a standalone app that you can 'input' a time / speed curve ?
Thanks for hints and
best regards to everybody

Klaus

Melodyne works with tempo maps and can be used to change tempo. I haven't tried it for this. Their manual is on line.