Create a handle and open a connection to the preferred audio interface
#include <sys/asoundlib.h> int snd_pcm_open_preferred( snd_pcm_t **handle, int *rcard, int *rdevice, int mode );
You can OR this flag with any of the above:
You can change the blocking setup later by calling snd_pcm_nonblock_mode().
The snd_pcm_open_preferred() function is an extension to the snd_pcm_open() function that attempts to open the user-selected default (or preferred) device for the system.
|If you use this function, your application will be more flexible than if you use snd_pcm_open().|
In a system where more then one PCM device exists, the user may set a preference for one of these devices. This function attempts to open that device and return a PCM handle to it. The function returns the card and device numbers if the rcard and rdevice arguments aren't NULL.
Here's the search order to find the preferred device:
pcmPreferredp card_number device_number pcmPreferredc card_number device_number
If all of the above fail, you don't have an audio system running.
Zero on success, or a negative value on error.
See the example in “Opening your PCM device” in the Playing and Capturing Audio Data chapter.
Successfully opening a PCM channel doesn't guarantee that there are enough audio resources free to handle your application. Audio resources (e.g. subchannels) are allocated when you configure the channel by calling snd_pcm_channel_params() or snd_pcm_plugin_params().
snd_pcm_close(), snd_pcm_nonblock_mode(), snd_pcm_open()