code.delx.au - pulseaudio/blob - src/sconv-s16le.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 <assert.h>
  27 #include <inttypes.h>
  28
  29 #include "endianmacros.h"
  30 #include "sconv.h"
  31
  32 #ifndef INT16_FROM
  33 #define INT16_FROM INT16_FROM_LE
  34 #endif
  35
  36 #ifndef INT16_TO
  37 #define INT16_TO INT16_TO_LE
  38 #endif
  39
  40 void pa_sconv_s16le_to_float32(unsigned n, const void *a, unsigned an, float *b) {
  41     const int16_t *ca = a;
  42     assert(n && a && an && b);
  43
  44     for (; n > 0; n--) {
  45         unsigned i;
  46         float sum = 0;
  47
  48         for (i = 0; i < an; i++) {
  49             int16_t s = *(ca++);
  50             sum += ((float) INT16_FROM(s))/0x7FFF;
  51         }
  52
  53         if (sum > 1)
  54             sum = 1;
  55         if (sum < -1)
  56             sum = -1;
  57
  58         *(b++) = sum;
  59     }
  60 }
  61
  62 void pa_sconv_s16le_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
  63     int16_t *cb = b;
  64     assert(n && a && b && bn);
  65
  66     for (; n > 0; n--) {
  67         unsigned i;
  68         int16_t s;
  69         float v = *(a++);
  70
  71         if (v > 1)
  72             v = 1;
  73         if (v < -1)
  74             v = -1;
  75
  76         s = (int16_t) (v * 0x7FFF);
  77         s = INT16_TO(s);
  78
  79         for (i = 0; i < bn; i++)
  80             *(cb++) = s;
  81     }
  82 }