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resample_template.c
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1 /*
2  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #if defined(CONFIG_RESAMPLE_DBL)
22 #define SET_TYPE(func) func ## _dbl
23 #define FELEM double
24 #define FELEM2 double
25 #define FELEML double
26 #define OUT(d, v) d = v
27 #define DBL_TO_FELEM(d, v) d = v
28 #elif defined(CONFIG_RESAMPLE_FLT)
29 #define SET_TYPE(func) func ## _flt
30 #define FELEM float
31 #define FELEM2 float
32 #define FELEML float
33 #define OUT(d, v) d = v
34 #define DBL_TO_FELEM(d, v) d = v
35 #elif defined(CONFIG_RESAMPLE_S32)
36 #define SET_TYPE(func) func ## _s32
37 #define FELEM int32_t
38 #define FELEM2 int64_t
39 #define FELEML int64_t
40 #define OUT(d, v) d = av_clipl_int32((v + (1 << 29)) >> 30)
41 #define DBL_TO_FELEM(d, v) d = av_clipl_int32(llrint(v * (1 << 30)));
42 #else
43 #define SET_TYPE(func) func ## _s16
44 #define FELEM int16_t
45 #define FELEM2 int32_t
46 #define FELEML int64_t
47 #define OUT(d, v) d = av_clip_int16((v + (1 << 14)) >> 15)
48 #define DBL_TO_FELEM(d, v) d = av_clip_int16(lrint(v * (1 << 15)))
49 #endif
50 
51 static void SET_TYPE(resample_one)(ResampleContext *c, int no_filter,
52  void *dst0, int dst_index, const void *src0,
53  int src_size, int index, int frac)
54 {
55  FELEM *dst = dst0;
56  const FELEM *src = src0;
57 
58  if (no_filter) {
59  dst[dst_index] = src[index];
60  } else {
61  int i;
62  int sample_index = index >> c->phase_shift;
63  FELEM2 val = 0;
64  FELEM *filter = ((FELEM *)c->filter_bank) +
65  c->filter_length * (index & c->phase_mask);
66 
67  if (sample_index < 0) {
68  for (i = 0; i < c->filter_length; i++)
69  val += src[FFABS(sample_index + i) % src_size] *
70  (FELEM2)filter[i];
71  } else if (c->linear) {
72  FELEM2 v2 = 0;
73  for (i = 0; i < c->filter_length; i++) {
74  val += src[abs(sample_index + i)] * (FELEM2)filter[i];
75  v2 += src[abs(sample_index + i)] * (FELEM2)filter[i + c->filter_length];
76  }
77  val += (v2 - val) * (FELEML)frac / c->src_incr;
78  } else {
79  for (i = 0; i < c->filter_length; i++)
80  val += src[sample_index + i] * (FELEM2)filter[i];
81  }
82 
83  OUT(dst[dst_index], val);
84  }
85 }
86 
87 static void SET_TYPE(set_filter)(void *filter0, double *tab, int phase,
88  int tap_count)
89 {
90  int i;
91  FELEM *filter = ((FELEM *)filter0) + phase * tap_count;
92  for (i = 0; i < tap_count; i++) {
93  DBL_TO_FELEM(filter[i], tab[i]);
94  }
95 }
96 
97 #undef SET_TYPE
98 #undef FELEM
99 #undef FELEM2
100 #undef FELEML
101 #undef OUT
102 #undef DBL_TO_FELEM