AuElementNotifyEvent − element notify event structure
#include <audio/audiolib.h>
typedef union _AuEvent
{
. . .
AuElementNotifyEvent auelementnotify;
. . .
}AuEvent;
typedef struct _AuElementNotifyEvent
{
int type;
AuUint32 serial;
AuBool send_event;
AuServer *server;
AuTime time;
AuFlowID flow;
unsigned char element_num;
unsigned char kind;
unsigned char prev_state;
unsigned char cur_state;
unsigned char reason;
AuUint32 num_bytes;
}AuElementNotifyEvent;
type |
The event type. ElementNotify events are type AuEventTypeElementNotify. |
||
serial |
The serial ID of the event expanded from the 16 bit value sent by the server. |
send_event
AuTrue if the event came from a SendEvent protocol request.
server |
The connection to the audio server that the event was read from. |
||
time |
The server time in milliseconds when the event was generated. |
||
flow |
The ID of the flow that caused the event. |
element_num
The index of the element that caused the event or AuElementAll to indicate the flow.
kind |
The kind of notify event. This will be one of these constants: AuElementNotifyKindLowWater, AuElementNotifyKindHighWater, or AuElementNotifyKindState. |
prev_state
The previous state of the element indexed by element_num. This will be one of these constants: AuStateStop, AuStateStart, or AuStatePause.
cur_state |
The current state of the element indexed by element_num. This will be one of these constants: AuStateStop, AuStateStart, or AuStatePause. |
||
reason |
The reason for the notify event. This will be one of these constants: AuReasonUser, AuReasonUnderrun, AuReasonOverrun, AuReasonEOF, AuReasonWatermark, or AuReasonHardware. |
||
num_bytes |
The number of bytes to send or receive. Only valid if the the element indexed by element_num is an ImportClient or ExportClient. |
ElementNotify events are sent to client applications to notify them of a watermark condition or state change. If kind is AuElementNotifyKindLowWater, the ImportClient element indexed by element_num in flow is ready to receive num_bytes of audio data from the client application. If kind is AuElementNotifyKindHighWater, the ExportClient element indexed by element_num in flow is ready to send num_bytes of audio data to the client application. If kind is AuElementNotifyKindState, the element indexed by element_num (or flow if element_num is AuElementAll) has made a state transition from prev_state to cur_state triggering the event. Reguardless of kind, prev_state and cur_state contain the old and new states and reason contains the reason for the event.
AuAnyEvent, AuErrorEvent, AuGrabNotifyEvent, AuMakeSendNotifyAction, AuMonitorNotifyEvent.
audiolib − Network Audio System C Language Interface