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 | */ |
30 | void NAME (void *opaque, struct st_sample *ibuf, struct st_sample *obuf, |
31 | size_t *isamp, size_t *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 | |
75 | /* if ipos overflow, there is a infinite loop */ |
76 | if (rate->ipos == 0xffffffff) { |
77 | rate->ipos = 1; |
78 | rate->opos = rate->opos & 0xffffffff; |
79 | } |
80 | /* See if we finished the input buffer yet */ |
81 | if (ibuf >= iend) { |
82 | goto the_end; |
83 | } |
84 | } |
85 | |
86 | icur = *ibuf; |
87 | |
88 | /* interpolate */ |
89 | #ifdef FLOAT_MIXENG |
90 | #ifdef RECIPROCAL |
91 | t = (rate->opos & UINT_MAX) * (1.f / UINT_MAX); |
92 | #else |
93 | t = (rate->opos & UINT_MAX) / (mixeng_real) UINT_MAX; |
94 | #endif |
95 | out.l = (ilast.l * (1.0 - t)) + icur.l * t; |
96 | out.r = (ilast.r * (1.0 - t)) + icur.r * t; |
97 | #else |
98 | t = rate->opos & 0xffffffff; |
99 | out.l = (ilast.l * ((int64_t) UINT_MAX - t) + icur.l * t) >> 32; |
100 | out.r = (ilast.r * ((int64_t) UINT_MAX - t) + icur.r * t) >> 32; |
101 | #endif |
102 | |
103 | /* output sample & increment position */ |
104 | OP (obuf->l, out.l); |
105 | OP (obuf->r, out.r); |
106 | obuf += 1; |
107 | rate->opos += rate->opos_inc; |
108 | } |
109 | |
110 | the_end: |
111 | *isamp = ibuf - istart; |
112 | *osamp = obuf - ostart; |
113 | rate->ilast = ilast; |
114 | } |
115 | |
116 | #undef NAME |
117 | #undef OP |
118 | |