Detailed Description
The PEvent class represents an event detected by a video analytics algorithm (PAnalytics); NOT thread-safe.
This class can be inherited.
For instance, SafeZoneEdge2d analytics plugin is an advanced plug-and-play motion detection on video streams. Each time you call Apply() to analyse a frame, it returns a list of PEvent which contains bounding boxes of all detected persons or vehicles (list can be empty is no motion detected).
To build an event, the simplest approach is to use the builder pattern, see following example: PEvent e = PEvent::Create("alarm", "", myDetector.GetId()).Certainty(0.7).Done(); Unless you develop a new PAnalytics plugin, you should not have to build your own events.
#include <PEvent.h>
Member Enumeration Documentation
◆ EEventTimeGranularity
Constructor & Destructor Documentation
◆ PEvent() [1/2]
| PEvent::PEvent | ( | ) |
Constructs an empty event.
The state of the object is the following:
- EventType is set to empty
- EventAnnotation is set to empty
- EventSource is set to PGuid::Null()
- EventSourceName is set to empty
- Payload is set to empty
- EventCertainty is set to 0
- OccurrenceTime is set to an invalid PDateTime
- TimeGranularity is set to PEvent::E_UNDEFINED
- DetectionTime is set to an invalid PDateTime
- EventId is set to PGuid::Null()
- EventComposition is set to false
- Ancestors is set to empty list
◆ PEvent() [2/2]
| PEvent::PEvent | ( | const PEvent & | other | ) |
Constructs a shared copy of other.
◆ ~PEvent()
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virtual |
Destroys this object.
Member Function Documentation
◆ AddAncestor()
| void PEvent::AddAncestor | ( | const PGuid & | ancestor | ) |
Add an ancestor for this event.
◆ Create()
|
static |
Returns a builder object to be able to create any event.
Typical usage is: PEvent e = PEvent::Create("alarm", "", myDetector.GetId()).Certainty(0.7).Done();
The following default parameters are applied:
- OccurrenceTime is set to current date/time
- TimeGranularity is set to PEvent::E_MILLISECONDS
- DetectionTime is set to OccurrenceTime
- EventId is set to a unique GUID (PGuid::CreateUniqueId())
◆ FromJSON()
Construct PEvent from JSON.
The format of JSON is defined in the schema defined in Event Schema. When constructing an event from JSON the header is fixed. However, the payload can contain any Papillon object. When constructing a PEvent the following rules are applied.
- All JSON integer are mapped to PInt64
- All JSON numbers are mapped to PDouble
- All JSON strings are mapped to PString
- All PDate or PDateTime timestamps must be in ISO 8601 format and UTC
- All PGuid must be in correct string format, i.e. five hex-fields separated by '-'.
- All PImage data must be in base-64 encoded string and compressed with JPG, PNG, TIF, BMP, WEBP, PNM or JP2. It is loaded using PImage::LoadFromBase64().
- All other Papillon objects must be in base-64 binary serialisation strings
See mirror function PEvent::ToJson()
- Parameters
-
jsonString The string in JSON format
◆ GetAncestors()
| const PList& PEvent::GetAncestors | ( | ) | const |
Get a list of all the ancestors for this event.
◆ GetAnnotation()
| const PString& PEvent::GetAnnotation | ( | ) | const |
Returns the text explanation of what happened in this event.
◆ GetCertainty()
| double PEvent::GetCertainty | ( | ) | const |
Returns the certainty if this event.
◆ GetComposition()
| bool PEvent::GetComposition | ( | ) | const |
Does this event have any ancestors.
◆ GetDetectionTime()
| const PDateTime& PEvent::GetDetectionTime | ( | ) | const |
Returns the detection time of this event, the time at which the event became known to the system.
◆ GetEventId()
| const PGuid& PEvent::GetEventId | ( | ) | const |
Returns the identifier of this event.
◆ GetOccurrenceTime()
| const PDateTime& PEvent::GetOccurrenceTime | ( | ) | const |
Returns the time at which the event occurred in the external system.
The precision of this timestamp is given by the event-types temporal granularity.
◆ GetPayload()
| const PProperties& PEvent::GetPayload | ( | ) | const |
Gets the payload associated with this event (read-only).
◆ GetSource()
| const PGuid& PEvent::GetSource | ( | ) | const |
Gets the source identifier of this event.
◆ GetSourceName()
| const PString& PEvent::GetSourceName | ( | ) | const |
Get the friendly name of the source of this event.
◆ GetTimeGranularity()
| EEventTimeGranularity PEvent::GetTimeGranularity | ( | ) | const |
Returns the time granularity of this event.
◆ GetType()
| const PString& PEvent::GetType | ( | ) | const |
Returns the event-type of this event.
◆ GetVersion()
| int PEvent::GetVersion | ( | ) | const |
Get the version number of the event format.
◆ operator=()
◆ operator==()
| bool PEvent::operator== | ( | const PEvent & | other | ) | const |
Returns true if this object is the same instance than other, false otherwise.
◆ SetAnnotation()
| void PEvent::SetAnnotation | ( | const PString & | eventAnnotation | ) |
Sets the event annotation which is a free text explanation of what happened in this event.
◆ SetCertainty()
| void PEvent::SetCertainty | ( | double | eventCertainty | ) |
Sets the event certainty which is an estimate of certainty of this event.
◆ SetComposition()
| void PEvent::SetComposition | ( | bool | eventComposition | ) |
Set if this event is composed or not.
◆ SetDetectionTime()
| void PEvent::SetDetectionTime | ( | const PDateTime & | detectionTime | ) |
Sets the detection time, the time at which the event became known to the system.
◆ SetEventId()
| void PEvent::SetEventId | ( | const PGuid & | eventId | ) |
Sets the event identifier.
Should be a system-generated unique ID for this event.
◆ SetOccurrenceTime()
| void PEvent::SetOccurrenceTime | ( | const PDateTime & | occurrenceTime | ) |
Sets the time at which the event occurred in the external system.
The precision of this timestamp is given by the event-types temporal granularity.
◆ SetPayload()
| PProperties& PEvent::SetPayload | ( | ) | const |
Returns the internal payload of this event; can be used to store any event specific information here.
◆ SetSource()
| void PEvent::SetSource | ( | const PGuid & | sourceId | ) |
Sets the source identifier of this event.
◆ SetSourceName()
| void PEvent::SetSourceName | ( | const PString & | sourceName | ) |
Set a friendly name for the source of this event.
◆ SetTimeGranularity()
| void PEvent::SetTimeGranularity | ( | EEventTimeGranularity | eventGranularity | ) |
Sets the precision of the any date/times in this event.
◆ SetType()
| void PEvent::SetType | ( | const PString & | eventType | ) | const |
Sets the event-type of this event.
The event-type uniquely identifies the type of event we are dealing with.
◆ ToJSON()
| PString PEvent::ToJSON | ( | const PStringList & | includeKeysFromPayload = PStringList() | ) | const |
Get the event as a JSON string.
The schema of the JSON is defined Event Schema. The schema has two parts a header and payload. The payload of events can store any Papillon object. When converting the payload to JSON the following rules are applied.
- PBool mapped to JSON boolean,
- PInt8, PUInt8, PInt16, PUInt16, PInt32, PUInt32, PInt64, PUInt64 are mapped to JSON integer
- PFloat and PDouble are mapped to JSON number
- PString are mapped are mapped to JSON string
All other Papillon objects are stored as JSON objects, with two fields. A type which is the Papillon class-name and a value which is a representation of that object. Note, the following rules are applied when saving the objects to the value field.
- PImage is saved as base-64 encoded JPG string - using PImage::ToJpegBase64()
- PDate and PDateTime are saved as a string in ISO 8601 format and UTC
- PGuid is saved as a string
- All other Papillon Objects are stored as base-64 encoded binary serialisation strings.
See mirror function PEvent::FromJson()
- Parameters
-
includeKeysFromPayload If this is specified, only include the data from the specified keys in the payload. If it is not specified, all keys are saved.
- Returns
- PString A string in JSON format
Friends And Related Function Documentation
◆ PEventBuilder
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friend |