ref: fdf38c9b21956b1aab29005f20bd9d1d5af7fe06
dir: /this.c/
#include <u.h>
#include <libc.h>
#include <thread.h>
#include "stretch.h"
enum{
Nrate = 44100,
Nchan = 2,
Sampsz = Nchan * 2,
};
void
usage(void)
{
fprint(2, "usage: %s [OPTIONS] [FILE]\n"
"-r F stretch ratio, [0.25,4.0] default 1.0\n"
"-g F gap/silence stretch ratio (if different)\n"
"-u N upper freq period limit [40,44100[ default 333 Hz\n"
"-l N lower freq period limit, [20,[ default 55 Hz\n"
"-b N audio buffer/window length, [1,100] default 25 ms\n"
"-t N gap/silence threshold (dB re FS, default -40)\n"
"-c cycle through all ratios, starting higher\n"
"-C cycle through all ratios, starting lower\n"
"-d force dual instance even for shallow ratios\n"
"-s scale rate to preserve duration (not pitch)\n"
"-f fast pitch detection (default >= 32 kHz)\n"
"-n normal pitch detection (default < 32 kHz)\n",
argv0);
exits("usage");
}
double
rms_level_dB (int16_t *audio, int samples, int channels)
{
double rms_sum = 0.0;
int i;
if (channels == 1)
for (i = 0; i < samples; ++i)
rms_sum += (double) audio [i] * audio [i];
else
for (i = 0; i < samples; ++i) {
double average = (audio [i * 2] + audio [i * 2 + 1]) / 2.0;
rms_sum += average * average;
}
return log10 (rms_sum / samples / (32768.0 * 32767.0 * 0.5)) * 10.0;
}
void
threadmain(int argc, char **argv)
{
int n, m, fd, ofd, pfd[2], cycle, dual, fast, normal, doscale, lf, uf, wsz, flags, maxnsamp, silence, nibuf, min_period, max_period, non_silence_frames, silence_frames, used_silence_frames, max_generated_stretch, max_generated_flush, samples_to_stretch, consecutive_silence_frames, verbose;
char *r;
s16int *prebuf, *ibuf, *obuf;
u32int insamp, outsamp;
float max_ratio;
double level, ratio, gap, smin;
StretchHandle S;
fd = 0;
ofd = 1;
cycle = 0; /* cycle ratio, direction, 1: fw, 2: back */
dual = 0; /* force dual instance */
fast = 0; /* force fast pitch detection */
normal = 0; /* force normal pitch detection */
doscale = 0; /* scale rate to preserve duration */
lf = 55; /* freq lower bound */
uf = 333; /* freq upper bound */
gap = 0.0; /* gap/silence stretch ratio */
ratio = 1.0; /* stretch ratio */
wsz = 25; /* window size */
smin = -40; /* gap/silence threshold */
verbose = 0;
ARGBEGIN{
case 'C': cycle = 2; break;
case 'c': cycle = 1; break;
case 'd': dual = 1; break;
case 'f': fast = 1; break;
case 'g': gap = strtod(EARGF(usage()), nil); if(gap < 0.25 || gap > 4.0) usage(); break;
case 'l': lf = strtol(EARGF(usage()), nil, 10); if(lf < 20) usage(); break;
case 'n': normal = 1; break;
case 'r': ratio = strtod(EARGF(usage()), nil); if(ratio < 0.25 || ratio > 4.0) usage(); break;
case 's': doscale = 1; break;
case 't': smin = strtod(EARGF(usage()), nil); if(smin < -70 || smin > -10) usage(); break;
case 'u': uf = strtol(EARGF(usage()), nil, 10); if(uf < 40) usage(); break;
case 'v': verbose = 1; break;
case 'w': wsz = strtol(EARGF(usage()), nil, 10); if(wsz < 1 || wsz > 100) usage(); break;
case 'h':
default: usage(); break;
}ARGEND
if(*argv != nil && (fd = open(*argv, OREAD)) < 0)
usage();
insamp = 0;
outsamp = 0;
min_period = Nrate / uf;
max_period = Nrate / lf;
flags = 0;
silence = gap != 0.0 && gap != ratio && !cycle;
nibuf = Nrate * (wsz / 1000.0);
max_ratio = ratio;
if(dual || ratio < 0.5 || ratio > 2.0 ||
(silence && (gap < 0.5 || gap > 2.0)))
flags |= STRETCH_DUAL_FLAG;
if((fast || Nrate >= 32000) && !normal)
flags |= STRETCH_FAST_FLAG;
if(verbose){
fprint(2, "file sample rate is %d Hz (%s), buffer size is %d samples\n",
Nrate, Nchan == 2 ? "stereo" : "mono", nibuf);
fprint(2, "stretch period range = %d to %d, %d channels, %s, %s\n",
min_period, max_period, 2, (flags & STRETCH_FAST_FLAG) ? "fast mode" : "normal mode",
(flags & STRETCH_DUAL_FLAG) ? "dual instance" : "single instance");
}
if((S = stretch_init(min_period, max_period, Nchan, flags)) == NULL)
sysfatal("initialization failed");
if(cycle)
max_ratio = (flags & STRETCH_DUAL_FLAG) ? 4.0 : 2.0;
else if(silence && gap > max_ratio)
max_ratio = gap;
maxnsamp = stretch_output_capacity(S, nibuf, max_ratio);
obuf = prebuf = nil;
if((ibuf = malloc(nibuf * Sampsz)) == nil
|| (obuf = malloc(maxnsamp * Sampsz)) == nil
|| silence && (prebuf = malloc(nibuf * Sampsz)) == nil)
sysfatal("malloc: %r");
non_silence_frames = 0,
silence_frames = 0,
used_silence_frames = 0;
max_generated_stretch = 0,
max_generated_flush = 0;
samples_to_stretch = 0,
consecutive_silence_frames = 1;
if(doscale){
if(pipe(pfd) < 0)
sysfatal("pipe: %r");
switch(rfork(RFPROC|RFFDG)){
case -1:
sysfatal("rfork: %r");
case 0:
close(0);
close(pfd[1]);
dup(pfd[0], 0);
if((r = smprint("s16c2r%d", (u32int)(Nrate * ratio + 0.5))) == nil)
sysfatal("smprint: %r");
execl("/bin/audio/pcmconv", "pcmconv", "-i", r, "-o", "s16c2r44100", nil);
sysfatal("execl: %r");
default:
close(1);
close(pfd[0]);
ofd = pfd[1];
}
}
for(;;){
n = read(fd, silence ? prebuf : ibuf, Sampsz * nibuf);
n /= Sampsz;
if(n < 0)
sysfatal("read: %r");
if(!silence && n == 0)
break;
insamp += n;
if(silence){
if(n != 0){
level = rms_level_dB(prebuf, n, Nchan);
if(level > smin){
consecutive_silence_frames = 0;
non_silence_frames++;
}
else{
consecutive_silence_frames++;
silence_frames++;
}
}
}
else
samples_to_stretch = n;
if(cycle){
if(flags & STRETCH_DUAL_FLAG)
ratio = (sin((double) outsamp / Nrate / 2.0) *(cycle & 1 ? 1.875 : -1.875)) + 2.125;
else
ratio = (sin((double) outsamp / Nrate) * (cycle & 1 ? 0.75 : -0.75)) + 1.25;
}
if(samples_to_stretch){
if(consecutive_silence_frames >= 3){
m = stretch_samples(S, ibuf, samples_to_stretch, obuf, gap);
used_silence_frames++;
}else
m = stretch_samples(S, ibuf, samples_to_stretch, obuf, ratio);
if(m){
if(m > max_generated_stretch)
max_generated_stretch = m;
write(ofd, obuf, Sampsz * m);
outsamp += m;
if(m > maxnsamp)
sysfatal("sample generation overflow");
}
}
if(silence){
if(n){
memcpy(ibuf, prebuf, n * Sampsz);
samples_to_stretch = n;
}else
break;
}
}
for(;;){
if((n = stretch_flush(S, obuf)) == 0)
break;
if(n > max_generated_flush)
max_generated_flush = n;
if(n > maxnsamp)
sysfatal("flush overflow");
write(ofd, obuf, Sampsz * n);
outsamp += n / Sampsz;
}
if(insamp && verbose){
fprint(2, "done, %ud samples --> %ud samples (ratio = %.3f)\n",
insamp, outsamp, (double)outsamp / insamp);
if(doscale)
fprint(2, "sample rate changed from %d Hz to %ud Hz\n",
Nrate, (u32int)(Nrate * ratio + 0.5));
fprint(2, "max expected samples = %d, actually seen = %d stretch, %d flush\n",
maxnsamp, max_generated_stretch, max_generated_flush);
if(silence_frames || non_silence_frames) {
int total_frames = silence_frames + non_silence_frames;
fprint(2, "%d silence frames detected (%.2f%%), %d actually used (%.2f%%)\n",
silence_frames, silence_frames * 100.0 / total_frames,
used_silence_frames, used_silence_frames * 100.0 / total_frames);
}
}
stretch_deinit(S);
exits(nil);
}