libavresample/resample_template.c

   1 /*
   2  * Copyright (c) 2004 Michael Niedermayer <michaelni@gmx.at>
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <math.h>
  22 #include <stdint.h>
  23
  24 #include "libavutil/common.h"
  25 #include "internal.h"
  26
  27 #if defined(CONFIG_RESAMPLE_DBL)
  28 #define SET_TYPE(func)  func ## _dbl
  29 #define FELEM         double
  30 #define FELEM2        double
  31 #define FELEML        double
  32 #define OUT(d, v) d = v
  33 #define DBL_TO_FELEM(d, v) d = v
  34 #elif defined(CONFIG_RESAMPLE_FLT)
  35 #define SET_TYPE(func)  func ## _flt
  36 #define FELEM         float
  37 #define FELEM2        float
  38 #define FELEML        float
  39 #define OUT(d, v) d = v
  40 #define DBL_TO_FELEM(d, v) d = v
  41 #elif defined(CONFIG_RESAMPLE_S32)
  42 #define SET_TYPE(func)  func ## _s32
  43 #define FELEM         int32_t
  44 #define FELEM2        int64_t
  45 #define FELEML        int64_t
  46 #define OUT(d, v) d = av_clipl_int32((v + (1 << 29)) >> 30)
  47 #define DBL_TO_FELEM(d, v) d = av_clipl_int32(llrint(v * (1 << 30)));
  48 #else
  49 #define SET_TYPE(func)  func ## _s16
  50 #define FELEM         int16_t
  51 #define FELEM2        int32_t
  52 #define FELEML        int64_t
  53 #define OUT(d, v) d = av_clip_int16((v + (1 << 14)) >> 15)
  54 #define DBL_TO_FELEM(d, v) d = av_clip_int16(lrint(v * (1 << 15)))
  55 #endif
  56
  57 static void SET_TYPE(resample_nearest)(void *dst0, int dst_index, const void *src0, unsigned int index)
  58 {
  59     FELEM *dst = dst0;
  60     const FELEM *src = src0;
  61     dst[dst_index] = src[index];
  62 }
  63
  64 static void SET_TYPE(resample_linear)(ResampleContext *c, void *dst0, int dst_index,
  65                                       const void *src0, unsigned int index, int frac)
  66 {
  67     FELEM *dst = dst0;
  68     const FELEM *src = src0;
  69     int i;
  70     unsigned int sample_index = index >> c->phase_shift;
  71     FELEM2 val = 0;
  72     FELEM *filter = ((FELEM *)c->filter_bank) +
  73                     c->filter_length * (index & c->phase_mask);
  74     FELEM2 v2 = 0;
  75
  76     for (i = 0; i < c->filter_length; i++) {
  77         val += src[sample_index + i] * (FELEM2)filter[i];
  78         v2  += src[sample_index + i] * (FELEM2)filter[i + c->filter_length];
  79     }
  80     val += (v2 - val) * (FELEML)frac / c->src_incr;
  81
  82     OUT(dst[dst_index], val);
  83 }
  84
  85 static void SET_TYPE(resample_one)(ResampleContext *c,
  86                                    void *dst0, int dst_index, const void *src0,
  87                                    unsigned int index, int frac)
  88 {
  89     FELEM *dst = dst0;
  90     const FELEM *src = src0;
  91     int i;
  92     unsigned int sample_index = index >> c->phase_shift;
  93     FELEM2 val = 0;
  94     FELEM *filter = ((FELEM *)c->filter_bank) +
  95                     c->filter_length * (index & c->phase_mask);
  96
  97     for (i = 0; i < c->filter_length; i++)
  98         val += src[sample_index + i] * (FELEM2)filter[i];
  99
 100     OUT(dst[dst_index], val);
 101 }
 102
 103 static void SET_TYPE(set_filter)(void *filter0, double *tab, int phase,
 104                                  int tap_count)
 105 {
 106     int i;
 107     FELEM *filter = ((FELEM *)filter0) + phase * tap_count;
 108     for (i = 0; i < tap_count; i++) {
 109         DBL_TO_FELEM(filter[i], tab[i]);
 110     }
 111 }
 112
 113 #undef SET_TYPE
 114 #undef FELEM
 115 #undef FELEM2
 116 #undef FELEML
 117 #undef OUT
 118 #undef DBL_TO_FELEM