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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
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