hdf - haskell data flow ----------------------- [Haskell][hs] library for uniform rate audio signal processing. It generates [C][c] code that requires either `RDL` (from [sc3-rdu][sc3-rdu]) or `jack-dl` (from [rju][rju]). The [SC2][sc2] [analog bubbles][ab] graph can be written: ~~~~ let o = lf_saw (mce2 8.0 7.23) 0.0 * 3.0 + 80.0 m = lf_saw 0.4 0.0 * 24.0 + o s = sin_osc (midi_cps m) 0.0 * 0.04 c = comb_n [0,1] 0.4 s 0.2 4.0 in out c ~~~~ The data flow graph this generates is:  The generated C-code (for `jack-dl`) is [c/gen/analog-bubbles.c](sw/hdf/c/gen/analog-bubbles.c). Slightly more elaborate, the [berlin 1977][b7] graph can be written: ~~~~ let clock_rate = 9 clock_time = 1 / clock_rate clock = impulse clock_rate 0 -- sequencer trigger tr = trigger clock note = sequ 0 [55,60,63,62,60,67,63,58] tr -- midi note pattern sequencer tr_16 = pulse_divider tr 16 0 -- divide tr by 16 note' = sequ 1 [-12,-7,-5,0,2,5] tr_16 + note -- transpose freq = midi_cps note' -- convert midi note to cycles per second env = decay2 clock (0.05 * clock_time) (2 * clock_time) amp = env * 0.1 + 0.02 -- amplitude envelope filt = env * (sin_osc 0.17 0 * 800) + 1400 -- filter frequency pw = sin_osc (mce2 0.08 0.09) 0 * 0.45 + 0.5 -- pulse width LFO(s) s = lf_pulse freq 0 pw * amp -- not bandlimited in out (comb_n [0,1] 0.2 (rlpf s filt 0.15) (mce2 0.2 0.17) 1.5) ~~~~ The data flow graph this generates is:  The generated C-code (for `jack-dl`) is [c/gen/berlin-1977.c](sw/hdf/c/gen/berlin-1977.c). <!-- These are from the small set of example [graphs][ix]. --> hdf implements `text-dl` for testing. [hs]: http://haskell.org/ [c]: http://c2.com/cgi/wiki?CeeLanguage [sc3-rdu]: http://rd.slavepianos.org/?t=sc3-rdu [rju]: http://rd.slavepianos.org/?t=rju [ab]: sw/hsc3-graphs/gr/analog-bubbles.scd [b7]: sw/hsc3-graphs/gr/berlin-1977.scd [sc2]: http://audiosynth.com/ [ix]: http://rd.slavepianos.org/?t=hdf&e=md/ix.md © [rohan drape][rd], 2006-2014, [gpl] [rd]: http://rd.slavepianos.org/ [gpl]: http://gnu.org/copyleft/