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

   1 #include <stdio.h>
   2 #include <stdlib.h>
   3 #include <assert.h>
   4 #include "endianmacros.h"
   5 #include "sconv.h"
   6
   7 #include "sconv-s16le.h"
   8 #include "sconv-s16be.h"
   9
  10 static void u8_to_float32(unsigned n, const void *a, unsigned an, float *b) {
  11     unsigned i;
  12     const uint8_t *ca = a;
  13     assert(n && a && an && b);
  14
  15     for (; n > 0; n--) {
  16         float sum = 0;
  17
  18         for (i = 0; i < an; i++) {
  19             uint8_t v = *(ca++);
  20             sum += (((float) v)-127)/127;
  21         }
  22
  23         if (sum > 1)
  24             sum = 1;
  25         if (sum < -1)
  26             sum = -1;
  27
  28         *(b++) = sum;
  29     }
  30 }
  31
  32 static void u8_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
  33     unsigned i;
  34     uint8_t *cb = b;
  35
  36     assert(n && a && b && bn);
  37     for (; n > 0; n--) {
  38         float v = *(a++);
  39         uint8_t u;
  40
  41         if (v > 1)
  42             v = 1;
  43
  44         if (v < -1)
  45             v = -1;
  46
  47         u = (uint8_t) (v*127+127);
  48
  49         for (i = 0; i < bn; i++)
  50             *(cb++) = u;
  51     }
  52 }
  53
  54 static void float32_to_float32(unsigned n, const void *a, unsigned an, float *b) {
  55     unsigned i;
  56     const float *ca = a;
  57     assert(n && a && an && b);
  58     for (; n > 0; n--) {
  59         float sum = 0;
  60
  61         for (i = 0; i < an; i++)
  62             sum += *(ca++);
  63
  64         if (sum > 1)
  65             sum = 1;
  66         if (sum < -1)
  67             sum = -1;
  68
  69         *(b++) = sum;
  70     }
  71 }
  72
  73 static void float32_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
  74     unsigned i;
  75     float *cb = b;
  76     assert(n && a && b && bn);
  77     for (; n > 0; n--) {
  78         float v = *(a++);
  79         for (i = 0; i < bn; i++)
  80             *(cb++) = v;
  81     }
  82 }
  83
  84 pa_convert_to_float32_func_t pa_get_convert_to_float32_function(enum pa_sample_format f) {
  85     switch(f) {
  86         case PA_SAMPLE_U8:
  87             return u8_to_float32;
  88         case PA_SAMPLE_S16LE:
  89             return pa_sconv_s16le_to_float32;
  90         case PA_SAMPLE_S16BE:
  91             return pa_sconv_s16be_to_float32;
  92         case PA_SAMPLE_FLOAT32:
  93             return float32_to_float32;
  94         default:
  95             return NULL;
  96     }
  97 }
  98
  99 pa_convert_from_float32_func_t pa_get_convert_from_float32_function(enum pa_sample_format f) {
 100     switch(f) {
 101         case PA_SAMPLE_U8:
 102             return u8_from_float32;
 103         case PA_SAMPLE_S16LE:
 104             return pa_sconv_s16le_from_float32;
 105         case PA_SAMPLE_S16BE:
 106             return pa_sconv_s16be_from_float32;
 107         case PA_SAMPLE_FLOAT32:
 108             return float32_from_float32;
 109         default:
 110             return NULL;
 111     }
 112 }