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audio/pcmconv: cleanup

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This commit is contained in:
cinap_lenrek 2012-12-12 19:04:57 +01:00
parent 985df234d6
commit a8b02eb198
1 changed files with 29 additions and 26 deletions
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55
sys/src/cmd/audio/pcmconv/pcmconv.c
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@ -23,9 +23,9 @@ struct Chan
ulong lΔ; /* filter step */
ulong le; /* filter end */
int u; /* unity scale */
int *h; /* filter coefficients */
int *hΔ; /* coefficient deltas for interpolation */
int u; /* unity scale */
int wx; /* extra samples */
int ix; /* buffer index */
@ -34,17 +34,13 @@ struct Chan
};
enum {
Nl = 8,
Nη = 8,
Np = Nl+Nη,
L = 1<<Np,
Nz = 13,
Nl = 8, /* 2^Nl samples per zero crossing in fir */
Nη = 8, /* phase bits for filter interpolation */
Np = Nl+Nη, /* phase bits (fract of fixed point) */
One = 1<<Np,
};
void
int
chaninit(Chan *c, int irate, int orate, int count)
{
static int h[] = {
@ -55,29 +51,35 @@ chaninit(Chan *c, int irate, int orate, int count)
c->ρ = ((uvlong)orate<<Np)/irate;
if(c->ρ == One)
return;
goto Done;
c->tΔ = ((uvlong)irate<<Np)/orate;
c->lΔ = L;
c->lΔ = 1<<(Nl+Nη);
c->le = nelem(h)<<Nη;
c->wx = 1 + (c->le / c->lΔ);
c->u = 13128; /* unity scale factor for fir */
if(c->ρ < One){
c->u *= c->ρ;
c->u >>= Np;
c->lΔ *= c->ρ;
c->lΔ >>= Np;
c->wx *= c->tΔ;
c->wx >>= Np;
}
c->le = nelem(h)<<Nη;
c->h = h;
if(!init){
init = 1;
for(n=0; n<nelem(hΔ)-1; n++)
hΔ[n] = h[n+1] - h[n];
}
c->h = h;
c->hΔ = hΔ;
c->u = 13128; /* unity scale factor for fir */
c->wx = 2*Nz*irate / orate;
c->ix = c->wx;
c->t = c->ix<<Np;
c->nx = c->wx*2 + count;
c->x = sbrk(sizeof(c->x[0]) * c->nx);
count += c->nx; /* account for buffer accumulation */
Done:
return ((uvlong)count * c->ρ) >> Np;
}
int
@ -418,7 +420,7 @@ main(int argc, char *argv[])
int *out, *in;
Chan ch[8];
Desc i, o;
int k, r, n, m;
int k, n, m, nin, nout;
vlong l;
void (*oconv)(int *, uchar *, int, int, int) = nil;
@ -473,21 +475,22 @@ main(int argc, char *argv[])
if(i.fmt == 'f' || o.fmt == 'f')
setfcr(getfcr() & ~(FPINVAL|FPOVFL));
n = (sizeof(ibuf)-i.framesz)/i.framesz;
r = n*i.framesz;
m = 3+(n*o.rate)/i.rate;
in = sbrk(sizeof(int) * n);
out = sbrk(sizeof(int) * m);
obuf = sbrk(o.framesz * m);
nin = (sizeof(ibuf)-i.framesz)/i.framesz;
in = sbrk(sizeof(int) * nin);
nout = 0;
memset(ch, 0, sizeof(ch));
for(k=0; k < i.channels; k++)
chaninit(&ch[k], i.rate, o.rate, n);
nout = chaninit(&ch[k], i.rate, o.rate, nin);
out = sbrk(sizeof(int) * nout);
obuf = sbrk(o.framesz * nout);
for(;;){
if(l >= 0 && l < r)
r = l;
n = cread(0, ibuf, r, i.framesz);
n = nin * i.framesz;
if(l >= 0 && l < n)
n = l;
n = cread(0, ibuf, n, i.framesz);
if(n < 0)
sysfatal("read: %r");
if(l > 0)