| Self-motivation (skip if your eyes are glazing over) |
[Feb. 13th, 2006|07:03 pm] |
Ideas that I want to try when I get my experimental FFT code running:
(A "frame" is a very short snip of sound - there will be just over 20 of them per second. A "bin" is how much energy there is at a certain frequency in that frame.)- Fauxverb - a synthesized reverb-like trail off the end of a sound. For each bin, look at the previous frame, and if it is less than X% of the previous amplitude, bring it up to that. We could even extrapolate the phase change from the previous two to be more exact. Could be made more controllable by making the value of "X" dependent on the frequency.
- Isolate - reject all sound that isn't panned within a certain region. Should be able to reasonably dissect stereo recordings into more than two channels.
- Max-mix - mix two sounds together, then adjust the amplitude of each bin to the louder of the two originals. This should counteract phase cancellations, if you're trying to replace an instrument that's already there - i.e. you're doubling a bass line but you don't want it to get quieter and louder as the old bass and new bass go in and out of phase with each other.
- Overflow - if there is too much energy in any one bin, reduce it to a certain limit and carry what you removed over into higher multiples of that frequency. This should add a gentle "brightening" to tones that are a little too loud.
- Phase align - force the left and right channels to be in phase. Louder bins get more weight. I don't know what this would be good for but I'd be curious to hear it.
- Smart limit - same as "overflow" but just throw the extra energy away instead of carrying it over.
- The twist - gradually shift one channel's phase by +90 degrees and the other by -90 degrees so that a sound goes 180 degrees out without changing the overall level of either channel. May have a small impact on perceived pitch in each channel.
- The watusi - sorry, there will be no such thing as "the watusi". Unless you can think of something. No "el dorado" either. Take this, brother, may it serve you well.
- Total separation - for two sounds that are recorded with microphones near each other, like an acoustic guitar and vocal. For any bin, if it is louder in the left, silence the right altogether, and vice versa.
- Transient - any bin that is louder in this frame than the one just before it and just after it is considered a transient - it can be removed by replacing this bin with an average of the one before and after it. (I might try to work this out so a transient can last for two frames, since it might fall right between two.)
Anyway. Look at all those potentially fun things I might be able to do. That should motivate me! |
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