Added option for cropping samples to a set width or detect it from beats

[jahu00]

I've added an option for cropping samples (actually images right before being converted into WAV) in the Riffusion tab. This can be useful when samples (like the ones produced by prompt travel) have excess length (appears to be most of the time for me). Cropped samples join more seamlessly.

There are two main options for cropping samples:

• Fixed width - you can open one generated image (preferably first) in an image manipulation program of your choice and eye where the excess begins
• Beat finder - I've made a somewhat naive algorithm for estimating where the sample should end. You input which horizontal slice of the image to check, find indexes with values above threshold (with certain minimum distance) and count beats to match a set rhythm, There isn't one set of parameters that fits all samples, but I've added a visualization for the beat finder to help tweak them to your need.

Image generated by the visualization (after getting settings just right).

This could be further improved by checking local maxima instead of just threshold (it's somewhat visible on the image, beats are detected when threshold is satisfied rather on the peak). Also, it might be possible to automate finding some of the settings (like horizontal slice or threshold).

If the code needs cleaning up, leave me a comment.

[enlyth]

Hey, thanks for all the effort.

I've invited you as a collaborator on the repo, since I don't have time right now to manage it or review PRs. Feel free to contribute what you think can improve it

[jahu00]

Ok, I think there other small improvements that can be made to the batch tool. I'll try doing those next,