snd_pcm_channel_params()
Set a PCM channel's configurable parameters
Synopsis:
#include <sys/asoundlib.h>
int snd_pcm_channel_params(
snd_pcm_t *handle,
snd_pcm_channel_params_t *params );
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().
- params
- A pointer to a snd_pcm_channel_params_t structure in which you've specified the PCM channel's configurable parameters. All members are write-only.
Library:
libasound.so
Use the -l asound option with qcc to link against this library.
Description:
The snd_pcm_channel_params() function sets up the transfer parameters according to the params structure.
You can call the function in SND_PCM_STATUS_NOTREADY (initial) and SND_PCM_STATUS_READY states; otherwise, snd_pcm_channel_params() returns -EBADFD.
If the parameters are valid (i.e., snd_pcm_channel_params() returns zero), the driver state is changed to SND_PCM_STATUS_READY.
Note:
The ability to convert audio to match hardware capabilities (for example, voice
conversion, rate conversion, type conversion, etc.) is enabled by default.
As a result, this function behaves as
snd_pcm_plugin_params(),
unless you've disabled the conversion by calling:
snd_pcm_plugin_set_disable(handle, PLUGIN_CONVERSION);
Returns:
EOK on success, a negative errno upon failure. The errno values are available in the errno.h file.
Errors:
Additional information for common error values:
- -EINVAL
- The state of handle is invalid, an invalid params was provided as input, or an invalid state change occurred. You can call snd_pcm_channel_status() to check if the state change was invalid and if you want to recover from the error.
Classification:
QNX Neutrino
| Safety: | |
|---|---|
| Cancellation point | No |
| Interrupt handler | No |
| Signal handler | Yes |
| Thread | Read the Caveats |
Caveats:
This function is not thread safe if handle (snd_pcm_t) is used across multiple threads.
Page updated: