Unwanted snapping when stretching audio

PeterDuke wrote on 7/1/2016, 8:26 PM

I have a multitrack audio project with no video. I have quantize to frames turned off and the normal snapping (F8) turned off. I have aligned all tracks to be in sync at the start but for some reason, some tracks are very slightly different in length. (The audio was generated by the Windows synthesizer using the Smartscore program).

When I try to resync at the end of the tracks by Ctrl-draggiing the end a track, I find that the drag gives a small jump in the vicinity of the original track length.

How can I prevent this jump? Holding shift as well as Ctrl to override snapping does not help.

Comments

musicvid10 wrote on 7/1/2016, 8:37 PM

With snapping and QTF turned off, and the audio ungrouped, the lowest logical unit of precision is one sample of the project frequency.

Are you zoomed in that far?
Does your project sample rate match your media sample rate?
Audio events terminating at subsample points are pretty common in my work. Are they audible?

PeterDuke wrote on 7/2/2016, 4:54 AM

What happened to my reply?

Here I go again.

I am zoomed in so that I can clearly see the beats in a bar (measure) and so that I can see both the end to Ctrl-drag and my reference notes for syncing

The sample rates now agree but it didn't help.

The out of sync is not obvious to casual listening. (No worse than live performance?)
The question is perhaps academic but you know what a fusspot I can be ...

I presume that the jump is implemented to permit a stretched track to be restored exactly back to the original.

Steve_Rhoden wrote on 7/2/2016, 5:56 AM

None of that is gonna work. You cant stretch audio like that and not have issues.
Use a filter, Like the built in "Time Stretch" plugin.
You will have no issues using that. The only thing, you will have to change your line
of thinking when working with it on the timeline with what you are doing.
It's quite versatile.

musicvid10 wrote on 7/2/2016, 7:16 AM

I guess I'm not understanding what you are seeing an hearing. Post a screenshot?

PeterDuke wrote on 7/2/2016, 9:02 PM

As I said, it is somewhat academic since the out of sync is only about 10 or 20 ms at the end of 3 minutes (ca 0.01%).

Can't you see the jump when you Ctrl-drag the end of the audio clip in the vicinity of its original length?

musicvid10 wrote on 7/2/2016, 10:13 PM

Oh, now I know what you mean -- it snaps to the original length or notch point when you get close.

I don't remember if I found a way to turn that off or not; in any event, I wouldn't stretch to cover a ragged end, which would possibly be covered with a fade in one of my projects.

Being a different kind of purist, and if it annoyed me, I would insert a tiny gap precisely at zero crossings, in a quiet spot somewhere the middle of the event, or every ten minutes in a longer program. I've resynced multiple audio sources (8 submixes) to a reference track that way using Pluraleyes, and with really good results.

PeterDuke wrote on 7/3/2016, 7:40 PM

Thanks for trying to help. I can live with the problem.