snd_pcm_set_filter()
Enable or disable the generation of PCM events
Synopsis:
#include <sys/asoundlib.h>
int snd_pcm_set_filter(snd_pcm_t *handle,
int channel,
const snd_pcm_filter_t * filter)
Arguments:
- handle
- 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().
- channel
- The channel to use. SND_PCM_CHANNEL_CAPTURE or SND_PCM_CHANNEL_PLAYBACK.
- filter
- A
constpointer to a snd_pcm_filter_t structure that defines a mask of events to track.
Library:
libasound.so
Use the -l asound option with qcc to link against this library.
Description:
The snd_pcm_set_filter() function uses the snd_pcm_filter_t structure to set the mask of all PCM events for the channel that the handle was opened on. Only those events that are specified in the mask are tracked; all others are discarded as they occur.
You can arrange to have your application receive notification when an event occurs by calling select() on the channel. You can use snd_pcm_channel_read_event() to read the event's data.
Returns:
EOK on success, a negative errno upon failure. The errno values are available in the errno.h file.
Errors:
- -EINVAL
- Invalid handle or filter is NULL.
Classification:
QNX Neutrino
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |
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