code.delx.au - pulseaudio/blob - polyp/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 Lesser 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 Lesser 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 #include "log.h"
  32
  33 #ifndef INT16_FROM
  34 #define INT16_FROM INT16_FROM_LE
  35 #endif
  36
  37 #ifndef INT16_TO
  38 #define INT16_TO INT16_TO_LE
  39 #endif
  40
  41 void pa_sconv_s16le_to_float32(unsigned n, const void *a, unsigned an, float *b) {
  42     const int16_t *ca = a;
  43     assert(n && a && an && b);
  44
  45     for (; n > 0; n--) {
  46         unsigned i;
  47         float sum = 0;
  48
  49         for (i = 0; i < an; i++) {
  50             int16_t s = *(ca++);
  51             sum += ((float) INT16_FROM(s))/0x7FFF;
  52         }
  53
  54         if (sum > 1)
  55             sum = 1;
  56         if (sum < -1)
  57             sum = -1;
  58
  59         *(b++) = sum;
  60     }
  61 }
  62
  63 void pa_sconv_s16le_from_float32(unsigned n, const float *a, void *b, unsigned bn) {
  64     int16_t *cb = b;
  65
  66 /*     pa_log("%u %p %p %u\n", n, a, b, bn); */
  67
  68     assert(n && a && b && bn);
  69
  70     for (; n > 0; n--) {
  71         unsigned i;
  72         int16_t s;
  73         float v = *(a++);
  74
  75         if (v > 1)
  76             v = 1;
  77         if (v < -1)
  78             v = -1;
  79
  80         s = (int16_t) (v * 0x7FFF);
  81         s = INT16_TO(s);
  82
  83         for (i = 0; i < bn; i++)
  84             *(cb++) = s;
  85     }
  86 }