Advanced Search

Finding out ALSA devices

/ Published in: C
Save to your folder(s)
This script finds out ALSA devices in Linux programatically, which can be a bit tricky.

Expand | Embed | Plain Text

Copy this code and paste it in your HTML 
  1. /**
  2.  * Reads audio devices from ALSA interface and returns count and array of
  3.  * strings containing the devices.
  4.  *
  5.  * @param[out] count Number of devices found.
  6.  * @param[out] Array of strings containing the device names.
  7.  *
  8.  */
  9. static void getALSADevices(int *count, char **devices)
  10. {
  11.   void **hints;
  12.   const char *ifaces[] = {"card", "pcm", "rawmidi", "timer", "seq", "hwdep", 0};
  13.   int index = 0;
  14.   void **str;
  15.   char *name;
  16.   char *desc;
  17.   char *io;
  18.   char *name_tmp;
  19.   char *desc_tmp;
  20.   int devIdx = 0;
  21.   int len;
  22.  
  23.   snd_config_update();
  24.  
  25.   while (ifaces[index]) {
  26.  
  27.     printf(" --- Trying interface %s ---\n", ifaces[index]);
  28.     if (snd_device_name_hint(-1, ifaces[index], &hints) < 0) {
  29.       printf("Querying devices failed for %s.\n", ifaces[index]);
  30.       index++;
  31.       continue;
  32.     }
  33.  
  34.     str = hints;
  35.  
  36.     while (*str) {
  37.       name = snd_device_name_get_hint(*str, "NAME");
  38.       desc = snd_device_name_get_hint(*str, "DESC");
  39.       io = snd_device_name_get_hint(*str, "IOID");
  40.  
  41.       len = strlen(name)+1;
  42.       name_tmp = (char*)malloc(len);
  43.       devices[devIdx] = name_tmp;
  44.       strcpy(name_tmp, name);
  45.       devices[devIdx][len-1] = '\0';
  46.  
  47.       printf("\n-- %s --\n", name);
  48.       printf("IO: %s\n", io);
  49.  
  50.       desc_tmp = strtok(desc, "\n");
  51.  
  52.       while (desc_tmp != NULL) {
  53.           printf("%s\n", desc_tmp);
  54.           desc_tmp = strtok(NULL, "\n");
  55.       }
  56.  
  57.       free(name);
  58.       free(desc);
  59.       devIdx++;
  60.       str++;
  61.     }
  62.     index++;
  63.     snd_device_name_free_hint(hints);
  64.   }
  65.   *count = devIdx;
  66.   return;
  67. }

Report this snippet


Comments

RSS Icon Subscribe to comments

You need to login to post a comment.