snd_ctl_pcm_channel_info()
Get information about a PCM channel's capabilities from a control handle
Synopsis:
#include <sys/asoundlib.h>
int snd_ctl_pcm_channel_info(
snd_ctl_t *handle,
int dev,
int chn,
int subdev,
snd_pcm_channel_info_t *info );
Arguments:
- handle
- The handle for the control connection to the card. This must be a handle created by snd_ctl_open() .
- dev
- The PCM device number.
- chn
- The channel direction; either SND_PCM_CHANNEL_CAPTURE or SND_PCM_CHANNEL_PLAYBACK.
- subdev
- The PCM subchannel.
- info
- A pointer to a snd_pcm_channel_info_t structure in which snd_ctl_pcm_channel_info() stores the information.
Library:
libasound.so
Use the -l asound option to qcc to link against this library.
Description:
The snd_ctl_pcm_channel_info() function fills the info structure with data about the PCM subchannel subdev in the PCM channel chn on the sound card selected by handle.
This function gets information about the complete capabilities of the system.
It's similar to
snd_pcm_channel_info()
and
snd_pcm_plugin_info()
,
but these functions get a dynamic snapshot of the system's
current capabilities, which can shrink and grow as subchannels are
allocated and freed.
Returns:
Zero on success, or a negative error code.
Errors:
- -EINVAL
- Invalid handle.
Classification:
QNX Neutrino
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Yes |