Finish processing all pending data in a PCM channel's queue and stop the channel
#include <sys/asoundlib.h> int snd_pcm_plugin_flush( snd_pcm_t *handle, int channel );
Use the -l asound option to qcc to link against this library.
The snd_pcm_plugin_flush() function flushes all unprocessed data in the driver queue:
- If the plugin is processing playback data, the call blocks until all data in the driver queue is played out the channel.
- If the plugin is processing capture data, any unread data in the driver queue is discarded.
If the operation is successful (zero is returned), the channel's state is changed to SND_PCM_STATUS_READY.
A positive number on success, or a negative value on error.
- The state of handle is invalid, an invalid channel was provided as input,or an invalid state change occurred. You can call snd_pcm_plugin_status() to check if the state change was invalid.
- The operation was interrupted because of a system signal (such as a timer) or an error was returned asynchronously
|Thread||Read the Caveats|
This function is not thread safe if handle (snd_pcm_t) is used across multiple threads.
Because the plugin interface may be subbuffering the written data until a complete driver block can be assembled, the flush call may have to inject up to (blocksize-1) samples into the channel so that the last block can be sent to the driver for playing. For this reason, the flush call may return a positive value indicating that this silence had to be inserted.
This function is the plugin-aware version of snd_pcm_channel_flush(). It functions exactly the same way, with the above caveat. However, make sure that you don't mix and match plugin- and nonplugin-aware functions in your application, or you may get undefined behavior and misleading results.
Last modified: 2014-06-24