1/*
2 * QEMU Mixing engine
3 *
4 * Copyright (c) 2004-2005 Vassili Karpov (malc)
5 * Copyright (c) 1998 Fabrice Bellard
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
20 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
23 * THE SOFTWARE.
24 */
25
26/*
27 * Processed signed long samples from ibuf to obuf.
28 * Return number of samples processed.
29 */
30void NAME (void *opaque, struct st_sample *ibuf, struct st_sample *obuf,
31           int *isamp, int *osamp)
32{
33    struct rate *rate = opaque;
34    struct st_sample *istart, *iend;
35    struct st_sample *ostart, *oend;
36    struct st_sample ilast, icur, out;
37#ifdef FLOAT_MIXENG
38    mixeng_real t;
39#else
40    int64_t t;
41#endif
42
43    ilast = rate->ilast;
44
45    istart = ibuf;
46    iend = ibuf + *isamp;
47
48    ostart = obuf;
49    oend = obuf + *osamp;
50
51    if (rate->opos_inc == (1ULL + UINT_MAX)) {
52        int i, n = *isamp > *osamp ? *osamp : *isamp;
53        for (i = 0; i < n; i++) {
54            OP (obuf[i].l, ibuf[i].l);
55            OP (obuf[i].r, ibuf[i].r);
56        }
57        *isamp = n;
58        *osamp = n;
59        return;
60    }
61
62    while (obuf < oend) {
63
64        /* Safety catch to make sure we have input samples.  */
65        if (ibuf >= iend) {
66            break;
67        }
68
69        /* read as many input samples so that ipos > opos */
70
71        while (rate->ipos <= (rate->opos >> 32)) {
72            ilast = *ibuf++;
73            rate->ipos++;
74            /* See if we finished the input buffer yet */
75            if (ibuf >= iend) {
76                goto the_end;
77            }
78        }
79
80        icur = *ibuf;
81
82        /* interpolate */
83#ifdef FLOAT_MIXENG
84#ifdef RECIPROCAL
85        t = (rate->opos & UINT_MAX) * (1.f / UINT_MAX);
86#else
87        t = (rate->opos & UINT_MAX) / (mixeng_real) UINT_MAX;
88#endif
89        out.l = (ilast.l * (1.0 - t)) + icur.l * t;
90        out.r = (ilast.r * (1.0 - t)) + icur.r * t;
91#else
92        t = rate->opos & 0xffffffff;
93        out.l = (ilast.l * ((int64_t) UINT_MAX - t) + icur.l * t) >> 32;
94        out.r = (ilast.r * ((int64_t) UINT_MAX - t) + icur.r * t) >> 32;
95#endif
96
97        /* output sample & increment position */
98        OP (obuf->l, out.l);
99        OP (obuf->r, out.r);
100        obuf += 1;
101        rate->opos += rate->opos_inc;
102    }
103
104the_end:
105    *isamp = ibuf - istart;
106    *osamp = obuf - ostart;
107    rate->ilast = ilast;
108}
109
110#undef NAME
111#undef OP
112