external hook

[dpwe]

Looks good.

• I would pass num_samples to the external hook. Of course it's always AMY_BLOCK_SIZE, but this external hook may be ignorant about Amy internals. It just makes sense as a signature IMO.
• SAMPLES is not the greatest type to be exporting - it's Amy-internal, and somewhat nonstandard (sign bit, 8 integer bits, 23 fractional bits). As it stands, the external hook is going to have to be pretty well-informed about Amy internals. I guess that's OK. The alternative would be to convert to int16 (like the waveform output) or float, but I can see why you don't want to do that.
• Why not have the function return a bool saying whether it consumed the samples? Less clumsy than a pointer to a return value.

[bwhitman]

OK on (1). on (2) i agree but not sure i want to do all that work per block. (3) sure, but i am not sure how to set up a function pointer that returns a value. i can ask the internet

[bwhitman]

Fixed up for (1) and (3). Gonna merge