src/pulseaudio.c

   1 /* Pulse Audio sound handler
   2  *
   3  * Copyright 2008 Chris Bagwell And Sundry Contributors
   4  */
   5
   6 #include "sox_i.h"
   7
   8 #include <pulse/simple.h>
   9 #include <pulse/error.h>
  10
  11 typedef struct {
  12   pa_simple *pasp;
  13 } priv_t;
  14
  15 static int setup(sox_format_t *ft, int is_input)
  16 {
  17   priv_t *pa = (priv_t *)ft->priv;
  18   char *server;
  19   pa_stream_direction_t dir;
  20   char *app_str;
  21   char *dev;
  22   pa_sample_spec spec;
  23   int error;
  24
  25   /* TODO: If user specified device of type "server:dev" then
  26    * break up and override server.
  27    */
  28   server = NULL;
  29
  30   if (is_input)
  31   {
  32     dir = PA_STREAM_RECORD;
  33     app_str = "record";
  34   }
  35   else
  36   {
  37     dir = PA_STREAM_PLAYBACK;
  38     app_str = "playback";
  39   }
  40
  41   if (strncmp(ft->filename, "default", (size_t)7) == 0)
  42     dev = NULL;
  43   else
  44     dev = ft->filename;
  45
  46   /* If user doesn't specify, default to some reasonable values.
  47    * Since this is mainly for recording case, default to typical
  48    * 16-bit values to prevent saving larger files then average user
  49    * wants.  Power users can override to 32-bit if they wish.
  50    */
  51   if (ft->signal.channels == 0)
  52     ft->signal.channels = 2;
  53   if (ft->signal.rate == 0)
  54     ft->signal.rate = 44100;
  55   if (ft->encoding.bits_per_sample == 0)
  56   {
  57     ft->encoding.bits_per_sample = 16;
  58     ft->encoding.encoding = SOX_ENCODING_SIGN2;
  59   }
  60
  61   spec.format = PA_SAMPLE_S32NE;
  62   spec.rate = ft->signal.rate;
  63   spec.channels = ft->signal.channels;
  64
  65   pa->pasp = pa_simple_new(server, "SoX", dir, dev, app_str, &spec,
  66                           NULL, NULL, &error);
  67
  68   if (pa->pasp == NULL)
  69   {
  70     lsx_fail_errno(ft, SOX_EPERM, "can not open audio device: %s", pa_strerror(error));
  71     return SOX_EOF;
  72   }
  73
  74   /* TODO: Is it better to convert format/rates in SoX or in
  75    * always let Pulse Audio do it?  Since we don't know what
  76    * hardware prefers, assume it knows best and give it
  77    * what user specifies.
  78    */
  79
  80   return SOX_SUCCESS;
  81 }
  82
  83 static int startread(sox_format_t *ft)
  84 {
  85     return setup(ft, 1);
  86 }
  87
  88 static int stopread(sox_format_t * ft)
  89 {
  90   priv_t *pa = (priv_t *)ft->priv;
  91
  92   pa_simple_free(pa->pasp);
  93
  94   return SOX_SUCCESS;
  95 }
  96
  97 static size_t read_samples(sox_format_t *ft, sox_sample_t *buf, size_t nsamp)
  98 {
  99   priv_t *pa = (priv_t *)ft->priv;
 100   size_t len;
 101   int rc, error;
 102
 103   /* Pulse Audio buffer lengths are true buffer lengths and not
 104    * count of samples. */
 105   len = nsamp * sizeof(sox_sample_t);
 106
 107   rc = pa_simple_read(pa->pasp, buf, len, &error);
 108
 109   if (rc < 0)
 110   {
 111     lsx_fail_errno(ft, SOX_EPERM, "error reading from pulse audio device: %s", pa_strerror(error));
 112     return SOX_EOF;
 113   }
 114   else
 115     return nsamp;
 116 }
 117
 118 static int startwrite(sox_format_t * ft)
 119 {
 120     return setup(ft, 0);
 121 }
 122
 123 static size_t write_samples(sox_format_t *ft, const sox_sample_t *buf, size_t nsamp)
 124 {
 125   priv_t *pa = (priv_t *)ft->priv;
 126   size_t len;
 127   int rc, error;
 128
 129   if (!nsamp)
 130     return 0;
 131
 132   /* Pulse Audio buffer lengths are true buffer lengths and not
 133    * count of samples. */
 134   len = nsamp * sizeof(sox_sample_t);
 135
 136   rc = pa_simple_write(pa->pasp, buf, len, &error);
 137
 138   if (rc < 0)
 139   {
 140     lsx_fail_errno(ft, SOX_EPERM, "error writing to pulse audio device: %s", pa_strerror(error));
 141     return SOX_EOF;
 142   }
 143
 144   return nsamp;
 145 }
 146
 147 static int stopwrite(sox_format_t * ft)
 148 {
 149   priv_t *pa = (priv_t *)ft->priv;
 150   int error;
 151
 152   pa_simple_drain(pa->pasp, &error);
 153   pa_simple_free(pa->pasp);
 154
 155   return SOX_SUCCESS;
 156 }
 157
 158 LSX_FORMAT_HANDLER(pulseaudio)
 159 {
 160   static char const *const names[] = { "pulseaudio", NULL };
 161   static unsigned const write_encodings[] = {
 162     SOX_ENCODING_SIGN2, 32, 0,
 163     0};
 164   static sox_format_handler_t const handler = {SOX_LIB_VERSION_CODE,
 165     "Pulse Audio client",
 166     names, SOX_FILE_DEVICE | SOX_FILE_NOSTDIO,
 167     startread, read_samples, stopread,
 168     startwrite, write_samples, stopwrite,
 169     NULL, write_encodings, NULL, sizeof(priv_t)
 170   };
 171   return &handler;
 172 }