Frequency interpolation nyquist plugin

[hypn666]

Hi everyone,

Im looking for nyquist plugin based on frequency interpolation (It will take a short section before and after selected sound and interpolate it those two parts) which can repair for example claps, hits etc in a sound. I know there is a "repair" plugin in beta version, but its only for really short sections (only 128 samples) and its not a in nyquist, so I want something for longer ones or short ones that doesnt really matter, I can edit it for my needs. Yeah, it wont be something special, when Ill apply it on longer section, but thats not a problem for me, its just a part of my bachelors work, but really needed part .
Im working on my own plugin, but because I have never worked with lisp and nyquist, so its really pain for me to write something advanced.

Would be greatful for every tip on this topic.

Thanks,
Hypn

[steve]

Does it really need to work on frequency interpolation? It would be much easier to make something that just cross-fades a mix of what went before and what goes after to "patch" the bad bit.

[hypn666]

Hey steve, thanks for the quick reply.

Yes, its required to be freq. interpolation. But as I wrote, Im new to lisp and not used to it. Im working with c#, java, php etc, so this is I little bit hard for me to work with, so I would be happy for everything that can repair sound (not mute it ), just to see, how it works...
At the moment, Im at stage where doing just basic stuff with my sound, reading lisp tutorials and looking on some other nyquist plugins .

[steve]

I wasn't suggesting "muting" the damaged sound. I was suggesting copying a short section from before the damage, and a short section from after the damage and using these copies to overwrite the damaged areas (using cross-fades to create a smooth transition).

If you insist of frequency interpolation you'll probably be needing this: http://audacity-forum.de/download/edgar ... torial.htm
(I can't help you with that - I don't understand it )

[hypn666]

I was just kidding with mute And yes, sadly FFT will be needed So is there some nyquist plugin to repair sound in any way, or mine will be worlds first?

[steve]

I've seen a few (and written a couple) of plug-ins for making repairs, but I've not seen one that uses frequency interpolation.

Good luck with it, and let us know how you get on.

(you know about the Audacity-Nyquist mailing list? http://n2.nabble.com/audacity-nyquist-f238279.html
It's never very busy, but it's there.)

[hypn666]

Hi,

Im back with some questions after some time. Ive managed to write a simple plugin that just cut selected area and crossfade both remaining ends. My question is... Is it possible to work with sound outside selected area? I mean, in my iterpolation plugin I select sound I want to repair and then I need to take its length and do fft to sound clips before and after this selected sound. Yes, the solution to this can be just select longer clip, then split it to 3 pieces and do what I want with them... Im just curious if its possile to work with area outside my selection.

Thanks.

[steve]

Is it possible to work with sound outside selected area?

Short answer - no.

Long answer -
The sound is passed from Audacity to Nyquist in the global variable "s" - which is an array for multi-channel (currently that means "stereo") sounds.
Audio files may be written/read to/from disk, but there are practical difficulties in using this for general release plug-ins as the default location *default-sf-dir* is not consistent across different platforms.
Some plug-ins (for example the vocoder) make use of stereo tracks to perform actions with 2 mono sounds (which must be manually combined into a stereo track by the user prior to applying the effect).
In the case of your plug-in, I think you've hit the nail on the head - "the solution to this can be just select longer clip, then split it to 3 pieces and do what I want with them... "

[steve]

Have you come across the *scratch* symbol? You can't use it for passing sounds, but you can use it for other data.
http://www.audacity-forum.de/download/e ... tm#scratch

[hypn666]

Hi guys,

after some time I was working on my plugin. And have a few questions again . So I think I managed to split selected sound into 3 pieces, but dont know how to test it. The easiest way would be to mute the middle piece, problem is dont know how So my code to split sound looks like this:

Code: Select all

(let*	((beg-sound (extract 0 +len+ channel))
		(mid-sound (extract +len+ (- 1 +len+) channel))
                (end-sound (extract (- 1 +len+) 1 channel))))

To be honest, dont know if its correct, but no errors in audacity so would be nice if u can write me how to mute middle piece. If this isnt correct, would be happy for any advice how to split the sound into 3 pieces. The +len+ is made like this:

Code: Select all

(setq +len+ (/ (get-duration 1) 3))

So it should be selection length/3. After I solve this, the next step is fft .

Thanks for answers.