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path: root/libswresample/resample_template.c (plain)
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1/*
2 * audio resampling
3 * Copyright (c) 2004-2012 Michael Niedermayer <michaelni@gmx.at>
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22/**
23 * @file
24 * audio resampling
25 * @author Michael Niedermayer <michaelni@gmx.at>
26 */
27
28#if defined(TEMPLATE_RESAMPLE_DBL)
29
30# define RENAME(N) N ## _double
31# define FILTER_SHIFT 0
32# define DELEM double
33# define FELEM double
34# define FELEM2 double
35# define FOFFSET 0
36# define OUT(d, v) d = v
37
38#elif defined(TEMPLATE_RESAMPLE_FLT)
39
40# define RENAME(N) N ## _float
41# define FILTER_SHIFT 0
42# define DELEM float
43# define FELEM float
44# define FELEM2 float
45# define FOFFSET 0
46# define OUT(d, v) d = v
47
48#elif defined(TEMPLATE_RESAMPLE_S32)
49
50# define RENAME(N) N ## _int32
51# define FILTER_SHIFT 30
52# define DELEM int32_t
53# define FELEM int32_t
54# define FELEM2 int64_t
55# define FELEM_MAX INT32_MAX
56# define FELEM_MIN INT32_MIN
57# define FOFFSET (1<<(FILTER_SHIFT-1))
58# define OUT(d, v) (d) = av_clipl_int32((v)>>FILTER_SHIFT)
59
60#elif defined(TEMPLATE_RESAMPLE_S16)
61
62# define RENAME(N) N ## _int16
63# define FILTER_SHIFT 15
64# define DELEM int16_t
65# define FELEM int16_t
66# define FELEM2 int32_t
67# define FELEML int64_t
68# define FELEM_MAX INT16_MAX
69# define FELEM_MIN INT16_MIN
70# define FOFFSET (1<<(FILTER_SHIFT-1))
71# define OUT(d, v) (d) = av_clip_int16((v)>>FILTER_SHIFT)
72
73#endif
74
75static void RENAME(resample_one)(void *dest, const void *source,
76 int dst_size, int64_t index2, int64_t incr)
77{
78 DELEM *dst = dest;
79 const DELEM *src = source;
80 int dst_index;
81
82 for (dst_index = 0; dst_index < dst_size; dst_index++) {
83 dst[dst_index] = src[index2 >> 32];
84 index2 += incr;
85 }
86}
87
88static int RENAME(resample_common)(ResampleContext *c,
89 void *dest, const void *source,
90 int n, int update_ctx)
91{
92 DELEM *dst = dest;
93 const DELEM *src = source;
94 int dst_index;
95 int index= c->index;
96 int frac= c->frac;
97 int sample_index = 0;
98
99 while (index >= c->phase_count) {
100 sample_index++;
101 index -= c->phase_count;
102 }
103
104 for (dst_index = 0; dst_index < n; dst_index++) {
105 FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;
106
107 FELEM2 val = FOFFSET;
108 FELEM2 val2= 0;
109 int i;
110 for (i = 0; i + 1 < c->filter_length; i+=2) {
111 val += src[sample_index + i ] * (FELEM2)filter[i ];
112 val2 += src[sample_index + i + 1] * (FELEM2)filter[i + 1];
113 }
114 if (i < c->filter_length)
115 val += src[sample_index + i ] * (FELEM2)filter[i ];
116#ifdef FELEML
117 OUT(dst[dst_index], val + (FELEML)val2);
118#else
119 OUT(dst[dst_index], val + val2);
120#endif
121
122 frac += c->dst_incr_mod;
123 index += c->dst_incr_div;
124 if (frac >= c->src_incr) {
125 frac -= c->src_incr;
126 index++;
127 }
128
129 while (index >= c->phase_count) {
130 sample_index++;
131 index -= c->phase_count;
132 }
133 }
134
135 if(update_ctx){
136 c->frac= frac;
137 c->index= index;
138 }
139
140 return sample_index;
141}
142
143static int RENAME(resample_linear)(ResampleContext *c,
144 void *dest, const void *source,
145 int n, int update_ctx)
146{
147 DELEM *dst = dest;
148 const DELEM *src = source;
149 int dst_index;
150 int index= c->index;
151 int frac= c->frac;
152 int sample_index = 0;
153#if FILTER_SHIFT == 0
154 double inv_src_incr = 1.0 / c->src_incr;
155#endif
156
157 while (index >= c->phase_count) {
158 sample_index++;
159 index -= c->phase_count;
160 }
161
162 for (dst_index = 0; dst_index < n; dst_index++) {
163 FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;
164 FELEM2 val = FOFFSET, v2 = FOFFSET;
165
166 int i;
167 for (i = 0; i < c->filter_length; i++) {
168 val += src[sample_index + i] * (FELEM2)filter[i];
169 v2 += src[sample_index + i] * (FELEM2)filter[i + c->filter_alloc];
170 }
171#ifdef FELEML
172 val += (v2 - val) * (FELEML) frac / c->src_incr;
173#else
174# if FILTER_SHIFT == 0
175 val += (v2 - val) * inv_src_incr * frac;
176# else
177 val += (v2 - val) / c->src_incr * frac;
178# endif
179#endif
180 OUT(dst[dst_index], val);
181
182 frac += c->dst_incr_mod;
183 index += c->dst_incr_div;
184 if (frac >= c->src_incr) {
185 frac -= c->src_incr;
186 index++;
187 }
188
189 while (index >= c->phase_count) {
190 sample_index++;
191 index -= c->phase_count;
192 }
193 }
194
195 if(update_ctx){
196 c->frac= frac;
197 c->index= index;
198 }
199
200 return sample_index;
201}
202
203#undef RENAME
204#undef FILTER_SHIFT
205#undef DELEM
206#undef FELEM
207#undef FELEM2
208#undef FELEML
209#undef FELEM_MAX
210#undef FELEM_MIN
211#undef OUT
212#undef FOFFSET
213
generated by cgit at 2024-05-17 18:52:57 (GMT)