a continuous buffer and looper

hey guys. ive been reading through msp's capabilities of recording audio.

I've wanted to find a decent looper vst that has a continuous running buffer, so that i can hit a button at any time and it will output the last 1,4 (and so on) bars of music, looping them. this is much better for live performance, because you can hit the loop button after you know you got it right, rather than hitting record and then being forced to get it right.

if you guys know of a looper that can do this i'd love to know, otherwise, i am going to set out and try to do it in msp.

but its going to be a lot to chew for me.

1. im wondering how you can continously go over say a 32 bar buffer again and again while still maintaining the information previously recorded in there.

2. then you'll be outputting 1,2,4,8, or 32 bars back from the playback position at the point the switch is pressed. that part shouldn't be hard at all.

3. this will also be taking recording information from ableton live, so im not sure if it would be possible to compensate for changes in tempo. well i guess its possible, but not without pitch shifting

im thinking i could possibly approach problem one by recording into 2 seperate buffer objects, one after the other. when you hit "loop", it could stop the input and then just start playing back the designated number of bars back from when the button was pressed. would this work?

thanks alot for any ideas or the best ways to approach this. im happy to share whatever i finish in the end when it all works!