code.delx.au - pulseaudio/blob - polyp/sconv.c

   1 /* $Id$ */
   2
   3 /***
   4   This file is part of polypaudio.
   5
   6   polypaudio is free software; you can redistribute it and/or modify
   7   it under the terms of the GNU General Public License as published
   8   by the Free Software Foundation; either version 2 of the License,
   9   or (at your option) any later version.
  10
  11   polypaudio is distributed in the hope that it will be useful, but
  12   WITHOUT ANY WARRANTY; without even the implied warranty of
  13   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  14   General Public License for more details.
  15
  16   You should have received a copy of the GNU General Public License
  17   along with polypaudio; if not, write to the Free Software
  18   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  19   USA.
  20 ***/
  21
  22 #ifdef HAVE_CONFIG_H
  23 #include <config.h>
  24 #endif
  25
  26 #include <stdio.h>
  27 #include <stdlib.h>
  28 #include <assert.h>
  29 #include "endianmacros.h"
  30 #include "sconv.h"
  31
  32 #include "sconv-s16le.h"
  33 #include "sconv-s16be.h"
  34
  35 static void u8_to_float32(unsigned n, const void *a, unsigned an, float *b) {
  36     unsigned i;
  37     const uint8_t *ca = a;
  38     assert(n && a && an && b);
  39
  40     for (; n > 0; n--) {
  41         float sum = 0;
  42
  43         for (i = 0; i < an; i++) {
  44             uint8_t v = *(ca++);
  45             sum += (((float) v)-127)/127;
  46         }
  47
  48         if (sum > 1)
  49             sum = 1;
  50         if (sum < -1)
  51             sum = -1;
  52
  53         *(b++) = sum;
  54     }
  55 }
  56
  57 static void u8_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
  58     unsigned i;
  59     uint8_t *cb = b;
  60
  61     assert(n && a && b && bn);
  62     for (; n > 0; n--) {
  63         float v = *(a++);
  64         uint8_t u;
  65
  66         if (v > 1)
  67             v = 1;
  68
  69         if (v < -1)
  70             v = -1;
  71
  72         u = (uint8_t) (v*127+127);
  73
  74         for (i = 0; i < bn; i++)
  75             *(cb++) = u;
  76     }
  77 }
  78
  79 static void float32_to_float32(unsigned n, const void *a, unsigned an, float *b) {
  80     unsigned i;
  81     const float *ca = a;
  82     assert(n && a && an && b);
  83     for (; n > 0; n--) {
  84         float sum = 0;
  85
  86         for (i = 0; i < an; i++)
  87             sum += *(ca++);
  88
  89         if (sum > 1)
  90             sum = 1;
  91         if (sum < -1)
  92             sum = -1;
  93
  94         *(b++) = sum;
  95     }
  96 }
  97
  98 static void float32_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
  99     unsigned i;
 100     float *cb = b;
 101     assert(n && a && b && bn);
 102     for (; n > 0; n--) {
 103         float v = *(a++);
 104         for (i = 0; i < bn; i++)
 105             *(cb++) = v;
 106     }
 107 }
 108
 109 pa_convert_to_float32_func_t pa_get_convert_to_float32_function(enum pa_sample_format f) {
 110     switch(f) {
 111         case PA_SAMPLE_U8:
 112             return u8_to_float32;
 113         case PA_SAMPLE_S16LE:
 114             return pa_sconv_s16le_to_float32;
 115         case PA_SAMPLE_S16BE:
 116             return pa_sconv_s16be_to_float32;
 117         case PA_SAMPLE_FLOAT32:
 118             return float32_to_float32;
 119         default:
 120             return NULL;
 121     }
 122 }
 123
 124 pa_convert_from_float32_func_t pa_get_convert_from_float32_function(enum pa_sample_format f) {
 125     switch(f) {
 126         case PA_SAMPLE_U8:
 127             return u8_from_float32;
 128         case PA_SAMPLE_S16LE:
 129             return pa_sconv_s16le_from_float32;
 130         case PA_SAMPLE_S16BE:
 131             return pa_sconv_s16be_from_float32;
 132         case PA_SAMPLE_FLOAT32:
 133             return float32_from_float32;
 134         default:
 135             return NULL;
 136     }
 137 }