Scrubbing and/or Slow Play

[John Sprung]

One thing I'd really like to have in Audacity is the ability to scrub with the mouse, or to play back very slowly. I'm very new to Audacity, and one thing I tried as a learning exercise is to remove artifacts from an old Edith Piaf record. There's a subtle little click that doesn't show up as an obvious spike in the wave form, no matter how I zoom in and scroll thru. But I can definitely hear it.

In the old days of magnetic film, this kind of thing could be found using a synchronizer with a playback head. We would crank the amp all the way up, and slowly turn the knob to move the offending place on the film back and forth under the head. That was called "scrubbing". Alternately, if we could play back at our choice of single digit frame rates, that would certainly server the same purpose.

Would this be a huge programming challenge?

All in all, I really like the program so far.



-- J.S.

[kozikowski]

<<<Would this be a huge programming challenge? >>>

Yes.

I would kill to be able to scrub like I can in my video editors.

http://forum.audacityteam.org/viewforum.php?f=20

Koz

[steve]

Scrubbing is one of the most asked for feature requests. It's on the list, but we've not got it yet.
I've added your vote here: http://wiki.audacityteam.org/index.php? ... e_Requests

or to play back very slowly. I

You can do that in Audacity 1.3.9 with the "Transcription" slider.

An alternative, and often easier way to find clicks is to switch the track to "Spectrum" view. Click on the name of the track and select "spectrum". Clicks will often show up as vertical red lines.

[waxcylinder]

Just to add to STF's advice about spectrum view - you may find the zooming in helps you spot the red line.

Note that repairing the click is easier in 1.3 than in 1.2 - In 1.2 you will need to interpolate and redraw the soundcurve youself by hand/mouse. In 1.3, provided the click is less than 128 sound samples then you can use the Repair Effect in Audacity which will interpolate a repaired waveform based on the neighbouring sound samples.

WC

[John Sprung]

Scrubbing is one of the most asked for feature requests. It's on the list, but we've not got it yet.
I've added your vote here: http://wiki.audacityteam.org/index.php? ... e_Requests

or to play back very slowly. I

You can do that in Audacity 1.3.9 with the "Transcription" slider.

An alternative, and often easier way to find clicks is to switch the track to "Spectrum" view. Click on the name of the track and select "spectrum". Clicks will often show up as vertical red lines.

Oops -- I actually already voted there, too. Should I go undo my extra vote? (I wouldn't want to pull a Big Jim "vote early and often" Thomson here.... )

I'll have to overcome by BetaPhobia and give 1.3.9 a try.

I looked both at the waveform and spectrum, and didn't find it initially. Just now, I tried again, and got it. It's not a spike. It looks like a high frequency low amplitude beep riding on the waveform. I saved a 0.40 sec example as an MP3, but uploading attachments with extensions is not allowed. Rough estimating from the waveform, it's noise at about 8475 Hz riding on a 238 Hz vocal note for a duration of 0.02 sec. with an amplitude about a quarter that of the vocal. The trick to finding such things, at least as they play on my machine, is that the cursor is past the anomaly in the waveform when I hear it.

Thanks again for the program and all your help.




-- J.S.

[waxcylinder]

I'll have to overcome by BetaPhobia and give 1.3.9 a try.

I think that Betaphobia is fairly uncalled for at this stage - 1.3.9 is now fairly mature and the next versions are reaching potential Release Candidate stage.

However, once 2.0 is released then your Betaphobia should return with a a vengeance (unless that is you are intertested in helping with the testing and QA). Early betas can be a very "interesting" ride ....

WC

[steve]

Early betas can be a very "interesting" ride ....

"Alpha" testing is pretty exciting too
Alpha versions are most definitely NOT for production use, but carefully selected beta versions replaced 1.2.6 alpha as my main audio editor quite some time ago. Currently I use 1.3.9 beta - it has a few minor issues, but it is pretty easy to work around these, and it is better than 1.2.6 by a long way.