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 OUT(d, v) d = v
36
37#elif    defined(TEMPLATE_RESAMPLE_FLT)
38
39#    define RENAME(N) N ## _float
40#    define FILTER_SHIFT 0
41#    define DELEM  float
42#    define FELEM  float
43#    define FELEM2 float
44#    define OUT(d, v) d = v
45
46#elif defined(TEMPLATE_RESAMPLE_S32)
47
48#    define RENAME(N) N ## _int32
49#    define FILTER_SHIFT 30
50#    define DELEM  int32_t
51#    define FELEM  int32_t
52#    define FELEM2 int64_t
53#    define FELEM_MAX INT32_MAX
54#    define FELEM_MIN INT32_MIN
55#    define OUT(d, v) v = (v + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\
56                      d = (uint64_t)(v + 0x80000000) > 0xFFFFFFFF ? (v>>63) ^ 0x7FFFFFFF : v
57
58#elif    defined(TEMPLATE_RESAMPLE_S16)
59
60#    define RENAME(N) N ## _int16
61#    define FILTER_SHIFT 15
62#    define DELEM  int16_t
63#    define FELEM  int16_t
64#    define FELEM2 int32_t
65#    define FELEML int64_t
66#    define FELEM_MAX INT16_MAX
67#    define FELEM_MIN INT16_MIN
68#    define OUT(d, v) v = (v + (1<<(FILTER_SHIFT-1)))>>FILTER_SHIFT;\
69                      d = (unsigned)(v + 32768) > 65535 ? (v>>31) ^ 32767 : v
70
71#endif
72
73static void RENAME(resample_one)(void *dest, const void *source,
74                                 int dst_size, int64_t index2, int64_t incr)
75{
76    DELEM *dst = dest;
77    const DELEM *src = source;
78    int dst_index;
79
80    for (dst_index = 0; dst_index < dst_size; dst_index++) {
81        dst[dst_index] = src[index2 >> 32];
82        index2 += incr;
83    }
84}
85
86static int RENAME(resample_common)(ResampleContext *c,
87                                   void *dest, const void *source,
88                                   int n, int update_ctx)
89{
90    DELEM *dst = dest;
91    const DELEM *src = source;
92    int dst_index;
93    int index= c->index;
94    int frac= c->frac;
95    int sample_index = index >> c->phase_shift;
96
97    index &= c->phase_mask;
98    for (dst_index = 0; dst_index < n; dst_index++) {
99        FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;
100
101        FELEM2 val=0;
102        int i;
103        for (i = 0; i < c->filter_length; i++) {
104            val += src[sample_index + i] * (FELEM2)filter[i];
105        }
106        OUT(dst[dst_index], val);
107
108        frac  += c->dst_incr_mod;
109        index += c->dst_incr_div;
110        if (frac >= c->src_incr) {
111            frac -= c->src_incr;
112            index++;
113        }
114        sample_index += index >> c->phase_shift;
115        index &= c->phase_mask;
116    }
117
118    if(update_ctx){
119        c->frac= frac;
120        c->index= index;
121    }
122
123    return sample_index;
124}
125
126static int RENAME(resample_linear)(ResampleContext *c,
127                                   void *dest, const void *source,
128                                   int n, int update_ctx)
129{
130    DELEM *dst = dest;
131    const DELEM *src = source;
132    int dst_index;
133    int index= c->index;
134    int frac= c->frac;
135    int sample_index = index >> c->phase_shift;
136#if FILTER_SHIFT == 0
137    double inv_src_incr = 1.0 / c->src_incr;
138#endif
139
140    index &= c->phase_mask;
141    for (dst_index = 0; dst_index < n; dst_index++) {
142        FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;
143        FELEM2 val=0, v2 = 0;
144
145        int i;
146        for (i = 0; i < c->filter_length; i++) {
147            val += src[sample_index + i] * (FELEM2)filter[i];
148            v2  += src[sample_index + i] * (FELEM2)filter[i + c->filter_alloc];
149        }
150#ifdef FELEML
151        val += (v2 - val) * (FELEML) frac / c->src_incr;
152#else
153#    if FILTER_SHIFT == 0
154        val += (v2 - val) * inv_src_incr * frac;
155#    else
156        val += (v2 - val) / c->src_incr * frac;
157#    endif
158#endif
159        OUT(dst[dst_index], val);
160
161        frac += c->dst_incr_mod;
162        index += c->dst_incr_div;
163        if (frac >= c->src_incr) {
164            frac -= c->src_incr;
165            index++;
166        }
167        sample_index += index >> c->phase_shift;
168        index &= c->phase_mask;
169    }
170
171    if(update_ctx){
172        c->frac= frac;
173        c->index= index;
174    }
175
176    return sample_index;
177}
178
179#undef RENAME
180#undef FILTER_SHIFT
181#undef DELEM
182#undef FELEM
183#undef FELEM2
184#undef FELEML
185#undef FELEM_MAX
186#undef FELEM_MIN
187#undef OUT
188