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

   1 #include <stdio.h>
   2 #include <assert.h>
   3
   4 #include "sample.h"
   5
   6 size_t pa_sample_size(const struct pa_sample_spec *spec) {
   7     assert(spec);
   8     size_t b = 1;
   9
  10     switch (spec->format) {
  11         case PA_SAMPLE_U8:
  12         case PA_SAMPLE_ULAW:
  13         case PA_SAMPLE_ALAW:
  14             b = 1;
  15             break;
  16         case PA_SAMPLE_S16LE:
  17         case PA_SAMPLE_S16BE:
  18             b = 2;
  19             break;
  20         case PA_SAMPLE_FLOAT32:
  21             b = 4;
  22             break;
  23         default:
  24             assert(0);
  25     }
  26
  27     return b * spec->channels;
  28 }
  29
  30 size_t pa_bytes_per_second(const struct pa_sample_spec *spec) {
  31     assert(spec);
  32     return spec->rate*pa_sample_size(spec);
  33 }
  34
  35
  36 uint32_t pa_samples_usec(size_t length, const struct pa_sample_spec *spec) {
  37     assert(spec);
  38
  39     return (uint32_t) (((double) length /pa_sample_size(spec))/spec->rate*1000000);
  40 }
  41
  42 int pa_sample_spec_valid(const struct pa_sample_spec *spec) {
  43     assert(spec);
  44
  45     if (!spec->rate || !spec->channels)
  46         return 0;
  47
  48     if (spec->format >= PA_SAMPLE_MAX)
  49         return 0;
  50
  51     return 1;
  52 }
  53
  54 int pa_sample_spec_equal(const struct pa_sample_spec*a, const struct pa_sample_spec*b) {
  55     assert(a && b);
  56
  57     return (a->format == b->format) && (a->rate == b->rate) && (a->channels == b->channels);
  58 }
  59
  60 void pa_sample_snprint(char *s, size_t l, const struct pa_sample_spec *spec) {
  61     static const char* const table[]= {
  62         [PA_SAMPLE_U8] = "U8",
  63         [PA_SAMPLE_ALAW] = "ALAW",
  64         [PA_SAMPLE_ULAW] = "ULAW",
  65         [PA_SAMPLE_S16LE] = "S16LE",
  66         [PA_SAMPLE_S16BE] = "S16BE",
  67         [PA_SAMPLE_FLOAT32] = "FLOAT32",
  68     };
  69
  70     assert(pa_sample_spec_valid(spec));
  71     snprintf(s, l, "%s %uch %uHz", table[spec->format], spec->channels, spec->rate);
  72 }