snd_pcm_query_chmaps()

Get a list of the available channel mappings for a PCM stream

Synopsis:

#include <sys/asoundlib.h>

snd_pcm_chmap_query_t **snd_pcm_query_chmaps( snd_pcm_t *pcm );

Arguments:

pcm: The handle for the PCM device, which you must have opened by calling snd_pcm_open_name(), snd_pcm_open(), or snd_pcm_open_preferred().

Library:

libasound.so

Use the -l asound option to qcc to link against this library.

Description:

(QNX Software Development Platform 6.6 io-audio patch [patch ID 4510] or later) The snd_pcm_query_chmaps() function returns a list of the available channel mappings for a PCM stream. To free this list, call snd_pcm_free_chmaps().

Returns:

A pointer to an array of snd_pcm_chmap_query_t structures that describe the mappings, or NULL if no mappings are available or an error occurred (errno is set).

Errors:

EINVAL: The value of pcm is NULL.
ENOMEM: Not enough memory was available.

Classification:

QNX Neutrino

Safety:
Cancellation point	No
Interrupt handler	No
Signal handler	Yes
Thread	Read the Caveats

Caveats:

This function isn't thread-safe if pcm (snd_pcm_t) is used across multiple threads.