conf_get_string
const char *conf_get_string(snd_config_t *root, const char *key1, const char *key2, const char *def);
array[index] = conf_get_string(cfg, buf, NULL, def);
desc = conf_get_string(pcm_cfg, "description", NULL, NULL);
cs = conf_get_string(pcm_cfg, "format", NULL, "S16_LE");
test_type = conf_get_string(pcm_cfg, "type", NULL, "time");