src/usr.bin/sndiod/dsp.c - diff

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Diff for /src/usr.bin/sndiod/dsp.c between version 1.18 and 1.19

version 1.18, 2021/07/05 08:29:59

version 1.19, 2024/04/22 11:01:02

Line 269

}

* resample the given number of frames

* Return the number of input and output frame that would be consumed

* by resamp_do(p, *icnt, *ocnt).

void

resamp_do(struct resamp *p, adata_t *in, adata_t *out, int todo)

resamp_getcnt(struct resamp *p, int *icnt, int *ocnt)

{

long long idiff, odiff;

int cdiff;

cdiff = p->oblksz - p->diff;

idiff = (long long)*icnt * p->oblksz;

odiff = (long long)*ocnt * p->iblksz;

if (odiff - idiff >= cdiff)

*ocnt = (idiff + cdiff + p->iblksz - 1) / p->iblksz;

else

*icnt = (odiff + p->diff) / p->oblksz;

}

* Resample the given number of frames. The number of output frames

* must match the corresponding number of input frames. Either always

* use icnt and ocnt such that:

* icnt * oblksz = ocnt * iblksz

* or use resamp_getcnt() to calculate the proper numbers.

void

resamp_do(struct resamp *p, adata_t *in, adata_t *out, int icnt, int ocnt)

{

unsigned int nch;

adata_t *idata;

unsigned int oblksz;

unsigned int ifr;

int s, ds, diff;

adata_t *odata;

unsigned int iblksz;

unsigned int ofr;

unsigned int c;

int64_t f[NCHAN_MAX];

adata_t *ctxbuf, *ctx;

unsigned int ctx_start;

int q, qi, qf, n;

#ifdef DEBUG

if (todo % p->iblksz != 0) {

log_puts("resamp_do: partial blocks not supported\n");

panic();

}

#endif

* Partially copy structures into local variables, to avoid

* unnecessary indirections; this also allows the compiler to

Line 300

Line 320

idata = in;

odata = out;

diff = p->oblksz;

diff = p->diff;

iblksz = p->iblksz;

oblksz = p->oblksz;

ctxbuf = p->ctx;

ctx_start = p->ctx_start;

nch = p->nch;

ifr = icnt;

ofr = ocnt;

* Start conversion.

#ifdef DEBUG

if (log_level >= 4) {

log_puts("resamp: copying ");

log_puti(ifr);

log_puts(" -> ");

log_putu(ofr);

log_puts(" frames, diff = ");

log_puti(diff);

log_puts("\n");

}

#endif

for (;;) {

if (diff >= oblksz) {

if (todo == 0)

if (ifr == 0)

break;

ctx_start = (ctx_start - 1) & (RESAMP_NCTX - 1);

ctx = ctxbuf + ctx_start;

Line 318

Line 354

ctx += RESAMP_NCTX;

}

diff -= oblksz;

todo--;

ifr--;

} else {

if (ofr == 0)

break;

for (c = 0; c < nch; c++)

f[c] = 0;

Line 361

Line 399

#endif

*odata++ = s;

}

diff += iblksz;

ofr--;

}

p->diff = diff;

p->ctx_start = ctx_start;

#ifdef DEBUG

if (ifr != 0) {

log_puts("resamp_do: ");

log_puti(ifr);

log_puts(": too many input frames\n");

panic();

}

if (ofr != 0) {

log_puts("resamp_do: ");

log_puti(ofr);

log_puts(": too many output frames\n");

panic();

}

#endif

}

static unsigned int

uint_gcd(unsigned int a, unsigned int b)

{

unsigned int r;

while (b > 0) {

r = a % b;

a = b;

b = r;

}

return a;

}

* initialize resampler with ibufsz/obufsz factor and "nch" channels

Line 375

Line 442

resamp_init(struct resamp *p, unsigned int iblksz,

unsigned int oblksz, int nch)

{

unsigned int g;

* reduce iblksz/oblksz fraction

g = uint_gcd(iblksz, oblksz);

iblksz /= g;

oblksz /= g;

* ensure weird rates don't cause integer overflow

while (iblksz > ADATA_UNIT || oblksz > ADATA_UNIT) {

iblksz >>= 1;

oblksz >>= 1;

}

p->iblksz = iblksz;

p->oblksz = oblksz;

p->diff = 0;

p->nch = nch;

p->ctx_start = 0;

memset(p->ctx, 0, sizeof(p->ctx));