Set data within the acoustic library in an APX module
#include <sys/asoundlib.h> int snd_pcm_set_apx_data( snd_pcm_t *pcm, uint32_t apx_id, snd_pcm_apx_param_t *param, const void *data );
The snd_pcm_set_apx_data() function retrieves data from the acoustic library in an APX, as specified in the snd_pcm_apx_param_t structure that param points to. For information on snd_pcm_apx_param_t, see snd_pcm_get_apx_data().
This API should not be used to set the external or user volume in the library because the change will not be reflected in the structures io-audio uses to automatically calculate these values and the change will be overwritten. Instead, use snd_pcm_set_apx_external_volume() and snd_pcm_set_apx_user_volume().
Because this function is only used with acoustic (SFO, SPM) APX modules, it must be called on the playback PCM device.
0 on success, or a negative errno value if an error occurred.
This function can also return the return values of devctl() (see devctl() in the QNX Neutrino C Library Reference).
One of the following causes:
QNX Neutrino
Safety: | |
---|---|
Cancellation point | Yes |
Interrupt handler | No |
Signal handler | Yes |
Thread | Yes |
This function is not thread safe if the handle (snd_pcm_t) is used across multiple threads.