snd_pcm_find()

Find all PCM devices in the system that meet the given criteria

Synopsis:

#include <sys/asoundlib.h>

int snd_pcm_find( unsigned int format, 
                  int *number, 
                  int *cards, 
                  int *devices, 
                  int mode );

Arguments:

format

Any combination of the SND_PCM_FMT_* constants. Here are the most commonly used flags:

• SND_PCM_FMT_U8 — unsigned 8-bit PCM.
• SND_PCM_FMT_S8 — signed 8-bit PCM.
• SND_PCM_FMT_U16_LE — unsigned 16-bit PCM little endian.
• SND_PCM_FMT_U16_BE — unsigned 16-bit PCM big endian.
• SND_PCM_FMT_S16_LE — signed 16-bit PCM little endian.
• SND_PCM_FMT_S16_BE — signed 16-bit PCM big endian.
• SND_PCM_FMT_IEC958_SUBFRAME — S/PDIF data (AC3).

number

The size of the card and device arrays that cards and devices point to. On return, number contains the total number of devices found.

cards

An array in which snd_pcm_find() stores the numbers of the cards it finds.

devices

An array in which snd_pcm_find() stores the numbers of the devices it finds.

mode

One of the following:

• SND_PCM_OPEN_PLAYBACK — the playback channel.
• SND_PCM_OPEN_CAPTURE — the capture channel.

Library:

libasound.so

Description:

The snd_pcm_find() function finds all PCM devices in the system that support any combination of the given format parameters in the given mode.

The card and device arrays are to be considered paired: the following uniquely defines the first PCM device:

card[0] + device[0] 

Returns:

A positive integer representing the total number of devices found (same as number on return), or a negative value on error.

Errors:

-EINVAL

Invalid mode or format.

Classification:

QNX Neutrino