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LinzerSchnitteMidibeta0.5.c
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LinzerSchnitteMidibeta0.5.c
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/*
LinzerSchnitte Midi Sound Server - Midi Interface for generating pure tones for controlling LinzerSchnitte
Copyright (C) 2014 Josh Gardiner
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>
Based on miniFMsynth by Matthias Nagorni.
*/
#include <stdio.h>
#include <stdlib.h>
#include <alsa/asoundlib.h>
#include <math.h>
#define POLY 10
#define GAIN 1000.0
#define BUFSIZE 1024
#define FREQ_START 300
#define FREQ_CHANNEL_WIDTH 100
snd_seq_t *seq_handle;
snd_pcm_t *playback_handle;
short *buf;
double phi[POLY], velocity[POLY], attack, decay, sustain, release, env_time[POLY], env_level[POLY];
int note[POLY], gate[POLY], note_active[POLY];
unsigned int rate = 48000;
/*int polyphony, buffersize, outputvolume, firstnotefreq, freqchannelwidth; */
/* TODO Make sample rate, buffer, gain and polyphony set from CL interface*/
void connect2MidiThroughPort(snd_seq_t *seq_handle) {
snd_seq_addr_t sender, dest;
snd_seq_port_subscribe_t *subs;
int myID;
myID=snd_seq_client_id(seq_handle);
fprintf(stderr,"MyID=%d",myID);
sender.client = 14;
sender.port = 0;
dest.client = myID;
dest.port = 0;
snd_seq_port_subscribe_alloca(&subs);
snd_seq_port_subscribe_set_sender(subs, &sender);
snd_seq_port_subscribe_set_dest(subs, &dest);
snd_seq_port_subscribe_set_queue(subs, 1);
snd_seq_port_subscribe_set_time_update(subs, 1);
snd_seq_port_subscribe_set_time_real(subs, 1);
snd_seq_subscribe_port(seq_handle, subs);
}
snd_seq_t *open_seq() {
snd_seq_t *seq_handle;
if (snd_seq_open(&seq_handle, "default", SND_SEQ_OPEN_DUPLEX, 0) < 0) {
fprintf(stderr, "Error opening ALSA sequencer.\n");
exit(1);
}
snd_seq_set_client_name(seq_handle, "LinzerSchnitteMIDI");
if (snd_seq_create_simple_port(seq_handle, "LinzerSchnitteMIDI",
SND_SEQ_PORT_CAP_WRITE|SND_SEQ_PORT_CAP_SUBS_WRITE,
SND_SEQ_PORT_TYPE_APPLICATION) < 0) {
fprintf(stderr, "Error creating sequencer port.\n");
exit(1);
}
return(seq_handle);
}
snd_pcm_t *open_pcm(char *pcm_name) {
snd_pcm_t *playback_handle;
snd_pcm_hw_params_t *hw_params;
snd_pcm_sw_params_t *sw_params;
if (snd_pcm_open (&playback_handle, pcm_name, SND_PCM_STREAM_PLAYBACK, 0) < 0) {
fprintf (stderr, "cannot open audio device %s\n", pcm_name);
exit (1);
}
snd_pcm_hw_params_alloca(&hw_params);
snd_pcm_hw_params_any(playback_handle, hw_params);
snd_pcm_hw_params_set_access(playback_handle, hw_params, SND_PCM_ACCESS_RW_INTERLEAVED);
snd_pcm_hw_params_set_format(playback_handle, hw_params, SND_PCM_FORMAT_S16_LE);
snd_pcm_hw_params_set_rate_near(playback_handle, hw_params, &rate, 0);
snd_pcm_hw_params_set_channels(playback_handle, hw_params, 2);
snd_pcm_hw_params_set_periods(playback_handle, hw_params, 2, 0);
snd_pcm_hw_params_set_period_size(playback_handle, hw_params, BUFSIZE, 0);
snd_pcm_hw_params(playback_handle, hw_params);
snd_pcm_sw_params_alloca(&sw_params);
snd_pcm_sw_params_current(playback_handle, sw_params);
snd_pcm_sw_params_set_avail_min(playback_handle, sw_params, BUFSIZE);
snd_pcm_sw_params(playback_handle, sw_params);
return(playback_handle);
}
double envelope(int *note_active, int gate, double *env_level, double t, double attack, double decay, double sustain, double release) {
if (gate) {
if (t > attack + decay) return(*env_level = sustain);
if (t > attack) return(*env_level = 1.0 - (1.0 - sustain) * (t - attack) / decay);
return(*env_level = t / attack);
} else {
if (t > release) {
if (note_active) *note_active = 0;
return(*env_level = 0);
}
return(*env_level * (1.0 - t / release));
}
}
/* TODO: ADD MIDI PANIC/ALL NOTES OFF */
int midi_callback() {
snd_seq_event_t *ev;
int l1;
do {
snd_seq_event_input(seq_handle, &ev);
switch (ev->type) {
case SND_SEQ_EVENT_NOTEON:
for (l1 = 0; l1 < POLY; l1++) {
if (!note_active[l1]) {
note[l1] = ev->data.note.note;
printf("Note ON %d FREQ %d\n", note[l1] ,(note[l1])*FREQ_CHANNEL_WIDTH+FREQ_START);
velocity[l1] = ev->data.note.velocity / 127.0;
env_time[l1] = 0;
gate[l1] = 1;
note_active[l1] = 1;
break;
}
}
break;
case SND_SEQ_EVENT_NOTEOFF:
for (l1 = 0; l1 < POLY; l1++) {
if (gate[l1] && note_active[l1] && (note[l1] == ev->data.note.note)) {
printf("Note OFF %d \n", note[l1]);
env_time[l1] = 0;
gate[l1] = 0;
}
}
break;
}
snd_seq_free_event(ev);
} while (snd_seq_event_input_pending(seq_handle, 0) > 0);
return (0);
}
int playback_callback (snd_pcm_sframes_t nframes) {
int l1, l2;
double dphi, freq_note, sound;
memset(buf, 0, nframes * 4);
for (l2 = 0; l2 < POLY; l2++) {
if (note_active[l2]) {
freq_note = (note[l2]*FREQ_CHANNEL_WIDTH)+FREQ_START;
/*debug printf(" Note Frequency %6.2f \n", freq_note); */
/* make faster by precompute delta phase*/
dphi = (M_PI * freq_note * 2) / (rate);
/*debug printf(" detaphase %6.6f ", dphi);*/
for (l1 = 0; l1 < nframes; l1++) {
phi[l2] += dphi;
/* make faster by precompute 2pi */
if (phi[l2] > 2.0 * M_PI) {
phi[l2] -= 2.0 * M_PI;
}
/* NEED faster OPTION THAN SIN (phi) */
/* maybe series expantion? */
/* maybe lookup tables? */
sound = GAIN * sin(phi[l2])* envelope(¬e_active[l2], gate[l2], &env_level[l2], env_time[l2], attack, decay, sustain, release);
env_time[l2] += 1.0 / rate;
buf[2 * l1] += sound;
buf[2 * l1 + 1] += sound;
}
}
}
return snd_pcm_writei (playback_handle, buf, nframes);
}
int main (int argc, char *argv[]) {
int nfds, seq_nfds, l1;
struct pollfd *pfds;
if (argc < 6) {
fprintf(stderr, "LinzerSchnitteMIDI <hw:0,0,1> <attack> <decay> <sustain> <release>\n");
exit(1);
}
attack = atof(argv[2]);
decay = atof(argv[3]);
sustain = atof(argv[4]);
release = atof(argv[5]);
/* polyphony = atoi(argv[6]);
buffersize = atoi(argv[7]);
outputvolume = atoi(argv[8]);
firstnotefreq = atoi(argv[9]);
freqchannelwidth = atoi(argv[10]);
*/
buf = (short *) malloc (2 * sizeof (short) * BUFSIZE);
playback_handle = open_pcm(argv[1]);
seq_handle = open_seq();
seq_nfds = snd_seq_poll_descriptors_count(seq_handle, POLLIN);
nfds = snd_pcm_poll_descriptors_count (playback_handle);
pfds = (struct pollfd *)alloca(sizeof(struct pollfd) * (seq_nfds + nfds));
snd_seq_poll_descriptors(seq_handle, pfds, seq_nfds, POLLIN);
snd_pcm_poll_descriptors (playback_handle, pfds+seq_nfds, nfds);
connect2MidiThroughPort(seq_handle);
for (l1 = 0; l1 < POLY; note_active[l1++] = 0);
while (1) {
if (poll (pfds, seq_nfds + nfds, 1000) > 0) {
for (l1 = 0; l1 < seq_nfds; l1++) {
if (pfds[l1].revents > 0) midi_callback();
}
for (l1 = seq_nfds; l1 < seq_nfds + nfds; l1++) {
if (pfds[l1].revents > 0) {
if (playback_callback(BUFSIZE) < BUFSIZE) {
fprintf (stderr, "xrun ! increase buffer \n");
snd_pcm_prepare(playback_handle);
}
}
}
}
}
snd_pcm_close (playback_handle);
snd_seq_close (seq_handle);
free(buf);
return (0);
}