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