Overview
The evAPI callback functions are used to receive event notifications from the exacqVision server, such as motion detected by a camera or a configuration change made to a server.
Usage
To use the evAPI callback functionality, it is necessary to define and declare a callback function and then assign the function in the API. The format of the definition for the EVAPI_Callback and EVAPI_CallbackEx functions can be found in the API documentation under the Core API module.
To assign the callback function to be used by evAPI, it is necessary to call EVAPI_SetCallback or EVAPI_SetCallbackEx. If both callbacks are assigned, the API will default to using the EVAPI_Callback function and will not execute the EVAPI_CallbackEx function.
Parameters
int param – the event identifier
int value – the event state
PayloadType *payload – data associated with event
size_t length – the size of the payload parameter
PayloadType
u32 camera – camera ID or device ID associated with an event
i32 time – UTC time of the event
u16 ms – millisecond part of the event time
u8 type – 0 for audio, >=1 for video
u8 flags – 0x80 for motion, 0x40 for alarm
u32 trigger – trigger ID associated with an event
i32 time_end – UTC time of the end of the event
u16 ms_end – millisecond part of the event end time
ParamTypes
ParamType Discover – indicates a server was found.
param – Discover
value – N/A
payload – NULL
length – size of payload
ParamType Login – indicates there was a login attempt on the server.
param – Login
value – 0 for success, otherwise error
payload – NULL
length – size of payload
ParamType Config – indicates configuration information has been sent from the server.
param – Config
value – N/A
payload – NULL
length – size of payload
Notes: A ParamType Config is sent any time the configuration of the server changes, such as when a camera is added or removed from the server or a soft trigger is created.
ParamType Status – indicates status information has been sent from the server.
param – Status
value – N/A
payload – NULL
length – size of payload
ParamType Loss – indicates that there is no video signal detected on an analog camera input for the camera id in the payload.
param – Loss
value – 1 for video loss, 0 for no video loss
payload – camera
time
ms
length – size of payload
ParamType Motion – indicates that motion was detected on the camera that corresponds to the camera id in the payload.
param – Motion
value – 1 for motion, 0 for no motion
payload – camera
time
ms
length – size of payload
ParamType Connected – indicates the server no longer detects a previously detected IP camera with the camera id in the payload.
param – Connection
value – 1 for connected, 0 for not connected
payload – camera
time
ms
length – size of payload
ParamType Live – indicates that a live video frame corresponding to the camera id in the payload has been received and decompressed.
param – Live
value – N/A
payload – camera
time
ms
type
flags
length – size of payload
Notes: The type payload field indicates whether audio or video data is being streamed. The flags payload field indicates whether motion or an alarm associated with the camera has been triggered.
ParamType Stored – indicates that a stored video frame corresponding to the camera id in the payload has been received but NOT decompressed.
param – Stored
value – N/A
payload – camera
time
ms
type
flags
length – size of payload
Notes: The type payload field indicates whether audio or video data is being streamed. The flags payload field indicates whether motion or an alarm associated with the camera has been triggered.
ParamType SoftTrigger – indicates that a soft trigger has been set to either on or off on the server.
param – SoftTrigger
value – 1 for trigger on, 0 for trigger off
payload – time
ms
trigger
length – size of payload
ParamType InputTrigger – indicates that an input trigger has been set to either on or off on the server.
param – InputTrigger
value – 1 for trigger on, 0 for trigger off
payload – camera
time
ms
trigger
length – size of payload
Notes: The camera payload field represents the device ID associated with the input trigger.
ParamType EVAPI_DISPLAY – indicates that a frame is ready for display after a call to EVAPI_SetFrame. This means that the frame has been decompressed.
param – EVAPI_DISPLAY
value – N/A
payload – camera
time
ms
type
flags
length – size of payload
ParamType EVAPI_SEARCH_COMPLETE – indicates the server has completed and sent all the found video or meta data from a search.
param – EVAPI_SEARCH_COMPLETE
value – N/A
payload – camera
time
ms
type
flags
length – size of payload
ParamType EVAPI_TEMPERATURE – indicates the temperature status of a device on the server.
param – EVAPI_TEMPERATURE
value – 1 for alarm, 0 for no alarm
payload – camera
time
ms (optional)
length – size of payload
Notes: The camera payload field may also represent a device_id.
ParamType EVAPI_LICENSE – indicates exacq license information has been received from the server.
param – EVAPI_LICENSE
value – N/A
payload – NULL
length – size of payload
ParamType EVAPI_DEVICE_FAIL – indicates that a capture card on the server has failed to initialize.
param – EVAPI_DEVICE_FAIL
value – 1 for alarm, 0 for no alarm
payload – camera (device ID)
– time
– ms (optional)
length – size of payload
ParamType EVAPI_STORAGE_ALARM – indicates the status of a storage drive on the server.
param – EVAPI_STORAGE_ALARM
value – 1 for over threshold, 0 for below or equal to threshold
payload – camera
time
ms
length – size of payload
Notes: The drive number associated with the alarm is indicated by the camera field of the Payload.
ParamType EVAPI_DEVICE_BUTTON – indicates the status of the front panel push button on the exacq server.
param – EVAPI_DEVICE_BUTTON
value – 1 for alarm, 0 for no alarm
payload – camera (device ID)
– time
– ms (optional)
length – size of payload
ParamType EVAPI_LICENSE_PACKET – indicates that a license packet has been received after a call to EVAPI_LicenseRequest.
param – EVAPI_LICENSE_PACKET
value – N/A
payload – NULL
length – size of payload
ParamType EVAPI_CORE_THROTTLING – indicates the status of the server throttling video.
param – EVAPI_CORE_THROTTLING
value – 1 for alarm, 0 for no alarm
payload – time
length – size of payload
ParamType EVAPI_DEVICE_FAN_FAIL – indicates the status a video capture card fan.
param – EVAPI_DEVICE_FAN_FAIL
value – 1 for alarm, 0 for no alarm
payload – camera (device ID)
– time
– ms (optional)
length – size of payload
ParamType EVAPI_SYS_MGMT – indicates the status of storage device.
param – EVAPI_SYS_MGMT
value – 1 for alarm, 0 for no alarm
payload – camera (storage ID)
– time
length – size of payload
ParamType UpdateStatus – indicates the status of a remote server update.
param – UpdateStatus
value –
INSTALL_TIMEOUT = -21,
INSTALL_ERROR = -20,
WGET_PARSE_ERROR = -17,
WGET_FILE_IO_ERROR = -16,
WGET_NETWORK_ERROR = -15,
WGET_SSL_ERROR = -14,
WGET_AUTH_ERROR = -13,
WGET_PROTOCOL_ERROR = -12,
WGET_HOST_ERROR = -11,
WGET_ERROR = -10,
INVALID_PATH_URI = -6,
INVALID_HOST_NAME = -5,
CHECKSUM_FAILED = -4,
INVALID_URI_LOCATION = -3,
NO_BUNDLE_NAME = -2,
UPDATE_FAILED = -1,
NO_UPDATE = 0,
BUNDLE_DOWNLOAD = 1,
BUNDLE_INSTALL = 2,
PENDING_UPDATE = 3,
BUNDLE_FILE = 4,
UPDATE_SUCCESS = 13
payload – time
length – size of payload
ParamType EVAPI_META_DATA_SEARCH – returns video meta data from a EVAPI_MetaDataSearch.
param – EVAPI_META_DATA_SEARCH
value – 0
payload – camera
– time (beginning of meta data block)
– flags (0x80 for motion, 0x40 for alarm, 0x0 for free run)
– time_end (end of meta data block)
length – size of payload
ParamType EVAPI_SOFT_TRIGGER_SEARCH – returns results from a soft trigger search.
param – EVAPI_SOFT_TRIGGER_SEARCH
value – 0
payload –
– time
– time_ms
– trigger
– time_end
– ms_end
length – size of payload
ParamType EVAPI_INPUT_TRIGGER_SEARCH – returns results from an input trigger search.
param – EVAPI_INPUT_TRIGGER_SEARCH
value – 0
payload –
– time
– time_ms
– trigger
– time_end
– ms_end
length – size of payload
ParamType EVAPI_ARCHIVE_ALARM – indicates if the server has lost connection to an archive target .
param – Connection
value – 1 for connected, 0 for not connected
payload – camera ( target ID)
– time
length – size of payload
Example
Function evCallback(parameters: int param, int value, PayloadType *payload, size_t length)
Switch on param
Case Discover
Do something
End Case
Case Login
Do something
End Case
….
Continue for other params
….
End Switch
End Function evCallback
Function Main
Initialize evAPI (EVAPI_INIT)
Set evAPI callback to evCallback (EVAPI_SetCallback)
….
Continue with other functions
….
End Function Main
Note: Samples of how to use the callback with C/C++ or C# are shipped with the SDK in the window and c-sharp samples.
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How-to-Using-EVAPI-Callback-and-EVAPI-CallbackEx.pdf
