Permalink
Find file
Fetching contributors…
Cannot retrieve contributors at this time
112 lines (97 sloc) 3.21 KB
/*
* QEMU Mixing engine
*
* Copyright (c) 2004-2005 Vassili Karpov (malc)
* Copyright (c) 1998 Fabrice Bellard
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
/*
* Processed signed long samples from ibuf to obuf.
* Return number of samples processed.
*/
void NAME (void *opaque, struct st_sample *ibuf, struct st_sample *obuf,
int *isamp, int *osamp)
{
struct rate *rate = opaque;
struct st_sample *istart, *iend;
struct st_sample *ostart, *oend;
struct st_sample ilast, icur, out;
#ifdef FLOAT_MIXENG
mixeng_real t;
#else
int64_t t;
#endif
ilast = rate->ilast;
istart = ibuf;
iend = ibuf + *isamp;
ostart = obuf;
oend = obuf + *osamp;
if (rate->opos_inc == (1ULL + UINT_MAX)) {
int i, n = *isamp > *osamp ? *osamp : *isamp;
for (i = 0; i < n; i++) {
OP (obuf[i].l, ibuf[i].l);
OP (obuf[i].r, ibuf[i].r);
}
*isamp = n;
*osamp = n;
return;
}
while (obuf < oend) {
/* Safety catch to make sure we have input samples. */
if (ibuf >= iend) {
break;
}
/* read as many input samples so that ipos > opos */
while (rate->ipos <= (rate->opos >> 32)) {
ilast = *ibuf++;
rate->ipos++;
/* See if we finished the input buffer yet */
if (ibuf >= iend) {
goto the_end;
}
}
icur = *ibuf;
/* interpolate */
#ifdef FLOAT_MIXENG
#ifdef RECIPROCAL
t = (rate->opos & UINT_MAX) * (1.f / UINT_MAX);
#else
t = (rate->opos & UINT_MAX) / (mixeng_real) UINT_MAX;
#endif
out.l = (ilast.l * (1.0 - t)) + icur.l * t;
out.r = (ilast.r * (1.0 - t)) + icur.r * t;
#else
t = rate->opos & 0xffffffff;
out.l = (ilast.l * ((int64_t) UINT_MAX - t) + icur.l * t) >> 32;
out.r = (ilast.r * ((int64_t) UINT_MAX - t) + icur.r * t) >> 32;
#endif
/* output sample & increment position */
OP (obuf->l, out.l);
OP (obuf->r, out.r);
obuf += 1;
rate->opos += rate->opos_inc;
}
the_end:
*isamp = ibuf - istart;
*osamp = obuf - ostart;
rate->ilast = ilast;
}
#undef NAME
#undef OP