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
RENAME(resample_one)75 static 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
RENAME(resample_common)88 static 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
RENAME(resample_linear)143 static 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