Counting Events

Overview

Counting events are generated when cameras count people or vehicles crossing a line or entering an area. All counting events have category == "counting".

Two API versions produce counting events:

• IPC v1.x -- uses the IntrusionDetection class for PASSLINECOUNT and TRAFFIC alarm types
• NVR v2.0 -- dedicated TargetCountingByLine and TargetCountingByArea classes

Event Types

IPC v1.x

Class	smartType	Alarm Description
IntrusionDetection	PASSLINECOUNT	Line Crossing Target Count
IntrusionDetection	TRAFFIC	Intrusion Target Count

IPC counting events reuse the IntrusionDetection class. They share the same base methods as other IPC events -- timestamps, camera name, images, and get_target_types() for the target filter (person, car, motor).

NVR v2.0

Class	smartType	Alarm Description
TargetCountingByLine	targetCountingByLine	Target Counting by Line
TargetCountingByArea	targetCountingByArea	Target Counting by Area

NVR counting events use the standard v2.0 base class (APIpostV2). They include channel ID, microsecond timestamps, and overview/target images when available.

IPC vs NVR Comparison

Feature	IPC v1.x	NVR v2.0
Line counting	Yes (PASSLINECOUNT)	Yes (targetCountingByLine)
Area counting	No	Yes (targetCountingByArea)
Target type filter	Via get_target_types()	Parsed from targetListInfo
Channel ID	No	Yes (get_channel_id())
Images	Yes	Yes

Common Properties

Available on all counting events (inherited from the base event classes):

Method	Returns	Description
get_ip_cam()	str	Camera device name
get_alarm_type()	str	Raw alarm type code (e.g., "PASSLINECOUNT", "targetCountingByLine")
get_alarm_description()	str	Human-readable description
get_time_stamp_formatted()	str	Timestamp like "2026-04-09 15:30:45"
get_time_stamp()	str	Unix timestamp string (for filenames)
source_image_exists()	bool	True if an overview/scene image is available
target_image_exists()	bool	True if a target crop image is available
get_source_image_bytes()	bytes or None	Overview image as JPEG bytes
get_target_image_bytes()	bytes or None	Target crop image as JPEG bytes

IPC-only:

Method	Returns	Description
get_target_types()	str	Supported target types from the camera (person, car, motor)

NVR-only:

Method	Returns	Description
get_channel_id()	str	NVR channel number

Code Examples

Basic Count Handling

def handle_event(event, client_ip):
    if event.category == "counting":
        alarm = event.get_alarm_description()
        camera = event.get_ip_cam()
        print(f"Count event: {alarm} on {camera}")

Filtering Line vs Area

def handle_event(event, client_ip):
    if event.category == "counting":
        alarm_type = event.get_alarm_type()

        if alarm_type in ("PASSLINECOUNT", "targetCountingByLine"):
            print("Line crossing count")
        elif alarm_type == "targetCountingByArea":
            print("Area count")

Distinguishing IPC vs NVR

from viewtron.events import TargetCountingByLine, TargetCountingByArea

def handle_event(event, client_ip):
    if event.category == "counting":
        if isinstance(event, (TargetCountingByLine, TargetCountingByArea)):
            # NVR v2.0 — has channel ID
            print(f"NVR channel {event.get_channel_id()}: {event.get_alarm_description()}")
        else:
            # IPC v1.x — has target type filter
            print(f"IPC count: {event.get_alarm_description()}")
            print(f"Target types: {event.get_target_types()}")

Related Pages

• ViewtronEvent -- common properties and category routing
• API Reference: Line Counting -- raw XML endpoint documentation, counting zone configuration