aboutsummaryrefslogtreecommitdiffstats
path: root/libswresample/resample_template.c
blob: 4c227b9940150543c52c11a7db6aafb56ca3cd06 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
/*
 * audio resampling
 * Copyright (c) 2004-2012 Michael Niedermayer <michaelni@gmx.at>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * audio resampling
 * @author Michael Niedermayer <michaelni@gmx.at>
 */

#if defined(TEMPLATE_RESAMPLE_DBL)

#    define RENAME(N) N ## _double
#    define FILTER_SHIFT 0
#    define DELEM  double
#    define FELEM  double
#    define FELEM2 double
#    define FOFFSET 0
#    define OUT(d, v) d = v

#elif    defined(TEMPLATE_RESAMPLE_FLT)

#    define RENAME(N) N ## _float
#    define FILTER_SHIFT 0
#    define DELEM  float
#    define FELEM  float
#    define FELEM2 float
#    define FOFFSET 0
#    define OUT(d, v) d = v

#elif defined(TEMPLATE_RESAMPLE_S32)

#    define RENAME(N) N ## _int32
#    define FILTER_SHIFT 30
#    define DELEM  int32_t
#    define FELEM  int32_t
#    define FELEM2 int64_t
#    define FELEM_MAX INT32_MAX
#    define FELEM_MIN INT32_MIN
#    define FOFFSET (1<<(FILTER_SHIFT-1))
#    define OUT(d, v) (d) = av_clipl_int32((v)>>FILTER_SHIFT)

#elif    defined(TEMPLATE_RESAMPLE_S16)

#    define RENAME(N) N ## _int16
#    define FILTER_SHIFT 15
#    define DELEM  int16_t
#    define FELEM  int16_t
#    define FELEM2 int32_t
#    define FELEML int64_t
#    define FELEM_MAX INT16_MAX
#    define FELEM_MIN INT16_MIN
#    define FOFFSET (1<<(FILTER_SHIFT-1))
#    define OUT(d, v) (d) = av_clip_int16((v)>>FILTER_SHIFT)

#endif

static void RENAME(resample_one)(void *dest, const void *source,
                                 int dst_size, int64_t index2, int64_t incr)
{
    DELEM *dst = dest;
    const DELEM *src = source;
    int dst_index;

    for (dst_index = 0; dst_index < dst_size; dst_index++) {
        dst[dst_index] = src[index2 >> 32];
        index2 += incr;
    }
}

static int RENAME(resample_common)(ResampleContext *c,
                                   void *dest, const void *source,
                                   int n, int update_ctx)
{
    DELEM *dst = dest;
    const DELEM *src = source;
    int dst_index;
    int index= c->index;
    int frac= c->frac;
    int sample_index = 0;

    while (index >= c->phase_count) {
        sample_index++;
        index -= c->phase_count;
    }

    for (dst_index = 0; dst_index < n; dst_index++) {
        FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;

        FELEM2 val = FOFFSET;
        FELEM2 val2= 0;
        int i;
        for (i = 0; i + 1 < c->filter_length; i+=2) {
            val  += src[sample_index + i    ] * (FELEM2)filter[i    ];
            val2 += src[sample_index + i + 1] * (FELEM2)filter[i + 1];
        }
        if (i < c->filter_length)
            val  += src[sample_index + i    ] * (FELEM2)filter[i    ];
#ifdef FELEML
        OUT(dst[dst_index], val + (FELEML)val2);
#else
        OUT(dst[dst_index], val + val2);
#endif

        frac  += c->dst_incr_mod;
        index += c->dst_incr_div;
        if (frac >= c->src_incr) {
            frac -= c->src_incr;
            index++;
        }

        while (index >= c->phase_count) {
            sample_index++;
            index -= c->phase_count;
        }
    }

    if(update_ctx){
        c->frac= frac;
        c->index= index;
    }

    return sample_index;
}

static int RENAME(resample_linear)(ResampleContext *c,
                                   void *dest, const void *source,
                                   int n, int update_ctx)
{
    DELEM *dst = dest;
    const DELEM *src = source;
    int dst_index;
    int index= c->index;
    int frac= c->frac;
    int sample_index = 0;
#if FILTER_SHIFT == 0
    double inv_src_incr = 1.0 / c->src_incr;
#endif

    while (index >= c->phase_count) {
        sample_index++;
        index -= c->phase_count;
    }

    for (dst_index = 0; dst_index < n; dst_index++) {
        FELEM *filter = ((FELEM *) c->filter_bank) + c->filter_alloc * index;
        FELEM2 val = FOFFSET, v2 = FOFFSET;

        int i;
        for (i = 0; i < c->filter_length; i++) {
            val += src[sample_index + i] * (FELEM2)filter[i];
            v2  += src[sample_index + i] * (FELEM2)filter[i + c->filter_alloc];
        }
#ifdef FELEML
        val += (v2 - val) * (FELEML) frac / c->src_incr;
#else
#    if FILTER_SHIFT == 0
        val += (v2 - val) * inv_src_incr * frac;
#    else
        val += (v2 - val) / c->src_incr * frac;
#    endif
#endif
        OUT(dst[dst_index], val);

        frac += c->dst_incr_mod;
        index += c->dst_incr_div;
        if (frac >= c->src_incr) {
            frac -= c->src_incr;
            index++;
        }

        while (index >= c->phase_count) {
            sample_index++;
            index -= c->phase_count;
        }
    }

    if(update_ctx){
        c->frac= frac;
        c->index= index;
    }

    return sample_index;
}

#undef RENAME
#undef FILTER_SHIFT
#undef DELEM
#undef FELEM
#undef FELEM2
#undef FELEML
#undef FELEM_MAX
#undef FELEM_MIN
#undef OUT
#undef FOFFSET