seamlessloop

seamlessloop

this project can take a piece of audio and convert it to a seamless loop and can optionally be quantized to the nearest beat. "seamless" means that zero clicks/pops from discontinuities should occur with this transformation.

the process is shown here using audacity:

in the case that the audio is too short (say 31 beats) then the audio is rounded to 32 beats and just appended with 1 beat of silence and the begining/end are given 5 ms fades to prevent clips.

install

the easiest way to install is to download the latest release.

first install Go, then go install github.com/schollz/seamlessloop@latest.

also you need to install Sox: https://sourceforge.net/projects/sox/

usage

you can specify a folder of files and specify a folder to output the resulting loops.

seamlessloop -in-folder INPUTFOLDER -out-folder OUTPUTFOLDER

the OUTPUTFOLDER will be created if it does not exist.

for example, you can make seamless quantized loops out of the files in this repo:

$ seamlessloop --in-folder src --out-folder quantized
wrote 'quantized/136/amenbreak_bpm136_beats8.wav'
wrote 'quantized/174/loop1_bpm174_beats16.wav'
wrote 'quantized/120/pad_bpm120_beats64.wav'

quantized loops

quantizing only works if you include bpmX in the filename of the sample being quantized. for example, this program will not quantize a file named sample.wav but will work if the filename is sample_bpm120.wav or bpm138_blahblah.wav, etc. the bpmX has to be in the filename for this program to work.

quantized seamless loops are made by first figuring out the closest 4/8/16-multiple beat and then implementing a crossfade between the extra end with the beginning. for example, if you have a 35-beat piece of audio it will crop it to 32 beats. the continuous piece of audio is made by taking the X+1 beat (in example, the 33rd beat) and fading it out, and then mixing it into the beginning which has been faded in.

if you are not using quantized loops (no bpmX in the filename) then it will use the -crossfade setting to determine the crossfade amount (default 1 second).

thanks

thanks to Frederik Olofsson for the crossfading graphic / explaination.