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Gear / Technical Help => Post-Processing, Computer / Streaming / Internet Devices & Related Activity => Topic started by: Chilly Brioschi on November 18, 2023, 10:59:32 AM

Title: Audacity - New Time Stretching Abilities, etc
Post by: Chilly Brioschi on November 18, 2023, 10:59:32 AM
Audacity has upped its game
The new version has a few very useful features.
  "Good and free"
Not heard spoken together very often...
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: capnhook on November 18, 2023, 11:30:57 AM



I call bullshit, watch their video



Tempo and beats mean nothing to us tapers, time stretch is not fine enough for our use



They deprecated the "Change Speed" again.....seriously doubt if it will take a 16-place decimal factor

(https://i.postimg.cc/0ym0sygb/change-speed-deprecated.jpg)



Everything is bullshit, as Willie and Micah fortold....

https://www.youtube.com/watch?v=GR7DAdocNOg

 :banging head:
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: robgronotte on November 19, 2023, 06:59:43 AM
What do you mean they "deprecated" it?
Do you actually think the program has gotten worse?
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: capnhook on November 19, 2023, 01:38:22 PM
If you look around here in these pages, us tapers have proven that something mysterious happened after v2.1.0 that truncated your fine 16-place decimal factor down to only about 4 places in the "Change Speed" function.

Don't know why they broke something that worked.

Has it been fixed, some report yes, I don't know and don't want to try

Their newest example looks depricated to the astute observer...

Here's v2.1.0 for comparison

(https://i.postimg.cc/3xGNkgq8/v2-1-0-Change-Speed.jpg)


Anybody want to test?

I got stuff to mix.. ;D
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: Chilly Brioschi on November 19, 2023, 02:00:11 PM
Wait, it was always there?

I'm writing the Audacity developer team and Time Team, dagnabbit !


                (https://notednames.com/ImgFame/hokfm_FamousChar.jpg)
It's a hokey BBC TV archeology show that the GF (archeology maj.) likes





OK,ok - silliness aside
Does this still work?
https://manual.audacityteam.org/man/sync_locked_track_groups_time_stretching.html
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: blakenan on December 08, 2023, 10:50:12 AM
I'm on a Mac, trying to use Audacity to mix a SBD and Aud source recorded on different decks.  As expected there is a small amount of drift over the course of a 2 hour show.  I'm trying to stretch the shorter source by a factor of 1.000022759 (drift was about 150ms over 2 hrs).  As suggested above, the current version of Audacity (v3.4.2) limits precision to 3 digits to the right of the decimal when specifying the "Speed Multiplier" in the "Change Speed and Pitch" options.  I tried running v2.1.0 but, as expected, it is not compatible with the latest MacOS. 

Any suggestions on other ways to stretch/mix these sources?  I've been out of the multi-source game for a long time...
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: Chilly Brioschi on December 08, 2023, 12:19:10 PM
My apologies for the lack of precision in my posting ...

Definitely email the developer's buglist
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: nulldogmas on December 08, 2023, 01:04:10 PM

Any suggestions on other ways to stretch/mix these sources?  I've been out of the multi-source game for a long time...

I use Sound Studio for this, but it costs money (I think around $30?).

EDIT: Actually $50 now, ugh. Its time stretching goes to lots of decimal places, though, and it has some other nice features.

https://apps.apple.com/us/app/sound-studio/id405537804?mt=12
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: boomfizzle on December 08, 2023, 01:24:31 PM
Any suggestions on other ways to stretch/mix these sources?  I've been out of the multi-source game for a long time...

Stretch Markers in Reaper.  More specifically, Magnetic Stretch Markers.  The relevant part comes at around 1:10 here: https://www.youtube.com/watch?v=pjKBp1b8n6o
(when I saw those wavs moving around together my jaw dropped)

I did a little more digging and found this trick, to create Transient Guides automatically https://youtu.be/GRO-ecLZqmw?t=448.

I used the transient guides to automatically locate the identical transients between the waveforms and used Magnetic Stretch Markers to line them up (snap and grid disabled) at the beginning and the end of the show.   Once those were synced up perfectly, I just started scrubbing through the files looking for stuff that seemed out of alignment.  I'd zoom in, look for a pair of transient guides that seemed to match up, click them to automatically create stretch markers, and I'd line them up using the Magnetic trick (zoomed all the way in to the level of plotted samples) and try again.   As long as I left the playhead within the stretch-markered region I was working on, every additional sync point would add additional clarity and phase alignment on playback.  If I added a new sync point and playback got wonky, I'd delete that set of markers and dive back into the transient guides, looking for a better match nearby.  Then I just cleared the Transient Guides when I was done to leave it with a cleaner look.
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: blakenan on December 08, 2023, 04:23:42 PM
All...  Thanks for the help.  I think I may have found a way to use Audacity.  Seems like this post in the Audacity forums might be a work around: https://forum.audacityteam.org/t/more-precise-speed-change-solved/65245/5.  I'll try and report back over the weekend.
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: blakenan on December 10, 2023, 12:00:56 PM
The approach cited in the post linked above works.  So, while Audacity "speed multiplier" precision on the "Change Speed" dialog is not very precise anymore (just 3 digits), you can make much more precise duration adjustments by changing by changing the units in the "Selection Length" section.  I used "Samples" to stretch a two hour section by just 7300 samples (about 0.25 seconds) by just adding 7300 to the current length with specifying the "new length".  Two sources are aligned within a few samples through out the two hour show.   
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: morst on December 11, 2023, 03:26:10 PM
Audacity 2.4.2 has the ability to do precise speed change down to the sample, using the Speed Change plugin. I use it regularly.


https://www.fosshub.com/Audacity-old.html (https://www.fosshub.com/Audacity-old.html)


Remember, versions of audacity 3.0 and after have some function where they contact an external server for some reason.


edit: I see where the problem is, ya got to set the NEW LENGTH mode to SAMPLES using that little downward pointing triangle where audacity loves to hide its super important features in a very much non-mac-like interface
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: breakonthru on December 11, 2023, 03:48:37 PM
good find

Audacity 2.4.2 has the ability to do precise speed change down to the sample, using the Speed Change plugin. I use it regularly.


https://www.fosshub.com/Audacity-old.html (https://www.fosshub.com/Audacity-old.html)


Remember, versions of audacity 3.0 and after have some function where they contact an external server for some reason.


edit: I see where the problem is, ya got to set the NEW LENGTH mode to SAMPLES using that little downward pointing triangle where audacity loves to hide its super important features in a very much non-mac-like interface
Title: Re: Audacity - New Time Stretching Abilities, etc
Post by: capnhook on December 11, 2023, 03:48:58 PM
Thanks morst  :coolguy:

I don't do the sample method

I calculate percent change and enter a long decimal in the box, and found that the next version above V2.1.0 truncated and rounded my 16 digits to about 4 places


Can anyone test Audacity 2.4.2 (or other versions above V2.1.0) with the time method, instead?