possible to make this plugin? ("auto draw wave")

[steve]

Code: Select all

(setf a (extract 0 0.5 s))
(setf b (extract 0.5 1 s))
(extract 0 1 (seq b a))

[N871]

works like a charm thank you! very last question! if you resample a track to a higher resolution, and you resample back to the original, is there any loss of quality?
Thanks for all your help!

[steve]

if you resample a track to a higher resolution, and you resample back to the original, is there any loss of quality?
Thanks for all your help!

Possibly, it depends how you do it, but in any case, not much.

[N871]

thanks, another "last" question if you don't mind

Is there a way in audacity to speed-shift multiple tracks at once to a same frequency? The change-percentage is different for all of them because they all have their own frequency...(chromatic samples)

[steve]

Is there a way in audacity to speed-shift multiple tracks at once to a same frequency?

If you want the code to detect the frequency and then calculate the amount of speed-shift to tune it to a specified frequency, that is difficult. The difficult part is to accurately detect the frequency, unless you already know something about the selected audio. For example, if you know that there are exactly 100 cycles of the waveform, then it is relatively easy to calculate the frequency. If it is just an arbitrary waveform of unknown frequency, then accurately determining the frequency is difficult.

[N871]

thank you for your reply, I can calculate the percentage for each track, just a lot of work to open the plugin window for each single track, but I finished it anyway.

The "find zero crossing point feature" is very practical..I almost don't dare to ask (you already helped me out a lot) but, would it be a lot of work to make a plugin
that does the same for a custom value (other than zero)? for example move the selection to the closest 0.257 points...best, Nils

[steve]

The "find zero crossing point feature" is very practical..I almost don't dare to ask (you already helped me out a lot) but, would it be a lot of work to make a plugin
that does the same for a custom value (other than zero)? for example move the selection to the closest 0.257 points...best, Nils

Nyquist effects only know about the audio that is passed to them, which is the "selected" audio. They have no idea about audio before or after the selection. The "find zero crossing" feature will search both forward and backward from the selection ends (both inside and outside of the selection) and look for the nearest zero crossing point, favouring positive going slopes. Nyquist can't "look outside of the selection".

[N871]

but it can look inside the selection, right? In fact this is how I would need it to work..I don't care about the close points outside the selection.

[steve]

Nyquist can find the first point in the selection where the waveform crosses any threshold that you specify, but it can't change the selection start/end point. Nyquist just receives a lump of audio (from the selection), processes it, and returns it to Audacity. Nyquist has no concept of tracks or selections, it only knows about the audio that is passed to it. So you could do "something" based on the point at which a specified level is first crossed, but you've not said what you want to do.

[N871]

I admire your patience with a newbie like myself

I would like the plugin to:
- silence all audio before the first "crossing point" in the selection
- silence all audio after the last "crossing point" in the selection

in other words, to trim the audio going from the first point to the second.