Audio File Scratching
Is it only possible to scratch audio files loaded into a buffer in Max/Msp or is it possible to scratch audio files loaded into say sfplay~ ? My whole dj player system is built using sfplays but I would like to implement a reasonably realistic sounding scratch effect.
Any pointers and threads anyone can guide me to.
First have a look at the help file for sfplay~ there you will find instructions (look in the ‘new features’ box) on how to alter the speed of sfplay~’s playback this is a good place to start for the sort of thing you are trying to do.
Instead of using speed you may want to investigate connecting line~, or some other signal based object to the right inlet on sfplay~ to do smooth speed changes.
I would also look into gizmo~ as well.
I would go with buffer~ and play~, this will let you "scrub" across
the sample. The trick is interpolating the audio between the control
ticks. You might want to estimate control change and accelleration to
You could feed the output of sfplay~ into tapin~/tapout~ and change the
delaytime with line~ to scratch back in time (increase delay, slow down)
or forth (shorten delay time, speed up)… You might want to put up two
tapout~s to be able to jump to zero without clicks.
Of course you can’t look into the future, this is kind of the same limit
a DJ would have with her vinyl, but this technique would allow you to
scratch even realtime input! Scratch your voice…
   
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hi,I found groove~ with buffer~ can achieve this. Also, if you wish to have an fast and obvious scratch feelings, you may try line~ to arise the speed rate when playback, because it can provide an rapid rise up that we cannot do by hand.