code.delx.au - pulseaudio/blob - polyp/sample.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 <assert.h>
  28
  29 #include "sample.h"
  30
  31 size_t pa_frame_size(const struct pa_sample_spec *spec) {
  32     assert(spec);
  33     size_t b = 1;
  34
  35     switch (spec->format) {
  36         case PA_SAMPLE_U8:
  37         case PA_SAMPLE_ULAW:
  38         case PA_SAMPLE_ALAW:
  39             b = 1;
  40             break;
  41         case PA_SAMPLE_S16LE:
  42         case PA_SAMPLE_S16BE:
  43             b = 2;
  44             break;
  45         case PA_SAMPLE_FLOAT32LE:
  46         case PA_SAMPLE_FLOAT32BE:
  47             b = 4;
  48             break;
  49         default:
  50             assert(0);
  51     }
  52
  53     return b * spec->channels;
  54 }
  55
  56 size_t pa_bytes_per_second(const struct pa_sample_spec *spec) {
  57     assert(spec);
  58     return spec->rate*pa_frame_size(spec);
  59 }
  60
  61 uint32_t pa_bytes_to_usec(size_t length, const struct pa_sample_spec *spec) {
  62     assert(spec);
  63
  64     return (uint32_t) (((double) length /pa_frame_size(spec))/spec->rate*1000000);
  65 }
  66
  67 int pa_sample_spec_valid(const struct pa_sample_spec *spec) {
  68     assert(spec);
  69
  70     if (!spec->rate || !spec->channels)
  71         return 0;
  72
  73     if (spec->format >= PA_SAMPLE_MAX)
  74         return 0;
  75
  76     return 1;
  77 }
  78
  79 int pa_sample_spec_equal(const struct pa_sample_spec*a, const struct pa_sample_spec*b) {
  80     assert(a && b);
  81
  82     return (a->format == b->format) && (a->rate == b->rate) && (a->channels == b->channels);
  83 }
  84
  85 void pa_sample_snprint(char *s, size_t l, const struct pa_sample_spec *spec) {
  86     static const char* const table[]= {
  87         [PA_SAMPLE_U8] = "U8",
  88         [PA_SAMPLE_ALAW] = "ALAW",
  89         [PA_SAMPLE_ULAW] = "ULAW",
  90         [PA_SAMPLE_S16LE] = "S16LE",
  91         [PA_SAMPLE_S16BE] = "S16BE",
  92         [PA_SAMPLE_FLOAT32LE] = "FLOAT32LE",
  93         [PA_SAMPLE_FLOAT32BE] = "FLOAT32BE",
  94     };
  95
  96     assert(pa_sample_spec_valid(spec));
  97     snprintf(s, l, "%s %uch %uHz", table[spec->format], spec->channels, spec->rate);
  98 }