Archipelago » qemu

/*

 * 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