Table of Contents

• 1. Introduction
• 2. Getting Started
• 3. Main Window Overview
• 4. Camera Views
• 5. How It Works
• 6. Web-Based Access
• 7. Configuration Guide
  • 7.1 Application Settings (lv.ini)
  • 7.2 Connecting Detection Applications
• 8. Troubleshooting

1. Introduction

The Metrici Live View Interface is a video monitoring display application designed to show live video feeds from other Metrici detection applications. This application acts as a "video wall" or monitoring display that collects images from up to 3 detection systems (such as License Plate Recognition, Area Counting, Parking Place Detection, and other Metrici detection software) and presents them in a unified viewing interface.

This manual is intended for end users who will operate and configure the application. It explains all features, options, and settings in an easy-to-understand manner.

What This Application Does

• Receives Images: Other Metrici detection applications send their processed video frames to this application
• Multi-Display: Shows up to 3 camera feeds simultaneously on one screen
• Flexible Layout: Arranges cameras vertically or horizontally based on your preference
• Web Broadcasting: Makes camera feeds available via web browsers for remote viewing
• Status Monitoring: Shows when camera connections are lost and displays a "No Stream" placeholder

What This Application Does NOT Do

• It does NOT perform video analysis - Detection and analysis are done by separate Metrici applications
• It does NOT connect directly to cameras - Images are received from other Metrici applications
• It does NOT control barriers or gates - That's handled by the detection applications
• It does NOT recognize license plates - LPR is performed by the LPR detection application
• It does NOT generate reports or events - Event reporting is done by the detection applications

Typical Setup

┌─────────────────┐     ┌─────────────────────────┐     ┌─────────────────────┐
│  Metrici LPR    │───▶│  Metrici Live View      │───▶│  Local Display +    │
│  Application    │     │  Interface (This App)   │     │  Web Browser Views  │
└─────────────────┘     └─────────────────────────┘     └─────────────────────┘
        │                         ▲
        │                         │
        │                   ┌─────┴─────┐
        │                   │  Metrici  │
        │                   │  Parking  │
        └──────────────────▶│  Detector │
                            └───────────┘
        

2. Getting Started

Starting the Application

The application is started by running the lv executable. When launched:

1. The application reads its configuration from lv.ini for general settings
2. The main window opens displaying the camera views
3. The web server starts listening for image submissions from detection applications
4. The application starts waiting to receive images from connected detection systems

Stopping the Application

To stop the application, simply close the main window using the standard window controls (X button or File → Exit).

3. Main Window Overview

The main window is the primary interface for monitoring camera feeds. It displays video streams received from configured detection applications.

Window Elements

Element	Description
Title Bar	Displays "Metrici Live View Interface v1.3" and the standard window controls
Camera Display Area	The central area where live video from detection applications is shown
Frame	A bordered panel that contains and organizes all camera views

Camera Display Behavior

• Active Feed: When a detection application is sending images, the live video is displayed
• Lost Connection: If a detection application stops sending images for more than 2 seconds, a "No Stream" placeholder image is displayed
• Automatic Scaling: Video images are automatically scaled to fit the available display area while maintaining proper proportions
• Real-Time Updates: Images are refreshed approximately 10 times per second (every 100 milliseconds)

4. Camera Views

The application can display video from up to 3 different detection applications. The number of visible views and their arrangement are configured in the settings.

Number of Views

You can configure how many detection feeds to display:

Setting Value	Result
1	Only Detection Feed 1 is displayed (full screen, largest size)
2	Detection Feeds 1 and 2 are displayed, sharing the screen space
3	All three detection feeds are displayed (smaller individual size)

Layout Arrangements

Vertical Arrangement (Default)

Detection feeds are arranged in a column, one above the other:

┌─────────────────────┐
│   Detection Feed 1  │
├─────────────────────┤
│   Detection Feed 2  │
├─────────────────────┤
│   Detection Feed 3  │
└─────────────────────┘
        

Best for: Monitoring long areas like entrance lanes, hallways, or when you need to see more vertical detail.

Horizontal Arrangement

Detection feeds are arranged in a row, side-by-side:

┌─────────────┬─────────────┬─────────────┐
│  Feed 1     │  Feed 2     │  Feed 3     │
└─────────────┴─────────────┴─────────────┘
        

Best for: Wide-area surveillance, parking lots, or when you want to compare feeds side-by-side.

Image Scaling

Video images are automatically scaled to fit their allocated display area:

• Height-Fit Priority: Images are scaled to match the height of their display area first
• Width Constraint: If scaling to height would make the image too wide, it's scaled down to fit the width instead
• Aspect Ratio: Original width-to-height proportions are always maintained to prevent distortion
• Dynamic Adjustment: When you resize the application window, images automatically resize to fit

Display Size Examples

Number of Views	Vertical Layout	Horizontal Layout
1 view	Nearly full screen height	Nearly full screen width
2 views	~50% screen height each	~50% screen width each
3 views	~33% screen height each	~33% screen width each

5. How It Works

Image Flow

1. Detection Applications Process Video
   Your Metrici detection applications (LPR, Parking Detector, Area Counter, etc.) connect to cameras and process the video to detect objects, license plates, or people.
2. Detection Apps Send Images to This Application
   Each detection application is configured to send its processed video frames to the Live View Interface application via HTTP POST requests.
3. This Application Receives and Displays
   The Live View Interface web server receives these images and updates the display in real-time.
4. Web Access
   Remote users can view the feeds by accessing the web URLs provided by this application.

Communication Protocol

Detection applications communicate with this application using HTTP:

• Method: HTTP POST (upload)
• URL: http://[this-computer]:8080/liveview[1-3]
• Content: JPEG image data
• Expected Response: The application responds with 9cddb6426465d1ada9a328e6c80258a0 to confirm receipt

URL Endpoints for Detection Applications

Configure your detection applications to send images to these URLs:

Detection Feed	URL to Configure in Detection App
Feed 1	http://[your-computer-ip]:8080/liveview1
Feed 2	http://[your-computer-ip]:8080/liveview2
Feed 3	http://[your-computer-ip]:8080/liveview3

6. Web-Based Access

The application includes a built-in web server that allows remote viewing of the camera feeds through any web browser.

Accessing Feeds via Web Browser

To view any of the detection feeds in a web browser:

Feed	Web URL
Feed 1	http://localhost:8080/liveview1
Feed 2	http://localhost:8080/liveview2
Feed 3	http://localhost:8080/liveview3

Setting Up Remote Access

By default, the web server only accepts connections from the local computer. To allow remote access:

1. Open lv.ini in a text editor
2. Find the host setting in the [listener] section
3. Change it from 127.0.0.1 to 0.0.0.0
4. Restart the application

What Happens If No Images Are Received?

If a detection application stops sending images:

• 0-2 seconds: The last received image continues to be displayed
• After 2 seconds: A "No Stream" placeholder image is shown to indicate the connection is lost
• Automatic Recovery: When the detection application starts sending images again, the feed automatically recovers

7. Configuration Guide

The application is configured using a single configuration file called lv.ini. This file controls the web server settings and how the camera views are arranged on screen.

7.1 Application Settings (lv.ini)

The lv.ini file contains all the settings for this application. It is organized into sections, with the main section being [listener].

Web Server Settings

These settings control how the web server operates:

Setting	Default Value	Description
host	127.0.0.1	The network address the web server listens on. Use 127.0.0.1 for local-only access, or 0.0.0.0 to accept connections from any network address.
port	8080	The TCP port number for the web server. Default is 8080. Common alternatives are 80 (HTTP standard), 443 (HTTPS), or 9000.
minThreads	4	Minimum number of threads to keep running for handling web requests. This ensures the server can always handle incoming connections.
maxThreads	100	Maximum number of threads for handling concurrent requests. Increase this if many users are accessing the web feeds simultaneously.
cleanupInterval	60000	How often (in milliseconds) to clean up inactive connections. 60000 = 60 seconds. Higher values use less memory but connections stay active longer.
readTimeout	60000	Timeout in milliseconds for reading requests. 60000 = 60 seconds. If a detection application takes longer, increase this value.
maxRequestSize	16000	Maximum size in bytes for standard HTTP requests (16000 bytes = ~16 KB).
maxMultiPartSize	10000000	Maximum size in bytes for image upload requests (10 MB by default). This should be larger than your expected JPEG image sizes.

Display Layout Settings

These settings control how the camera views are arranged:

Setting	Default Value	Description
vertical_arrangement	1	Controls camera layout. Set to 1 for vertical (stacked) layout, 0 for horizontal (side-by-side) layout.
number_of_views	3	Number of detection feeds to display. Valid values: 1, 2, or 3.

Example Configuration File

[listener]
host=127.0.0.1
port=8080
minThreads=4
maxThreads=100
cleanupInterval=60000
readTimeout=60000
maxRequestSize=16000
maxMultiPartSize=10000000
vertical_arrangement=1
number_of_views=3
        

7.2 Connecting Detection Applications

To receive images from detection applications, you need to configure those applications to send images to this application. This section explains how to set up the connections.

Configuration in Detection Applications

Each detection application (LPR, Parking Detector, Area Counter, etc.) needs to be configured with the correct URL to send images to this Live View Interface application.

Required URL Format

http://[live-view-computer-ip]:[port]/liveview[feed-number]
        

Configuration Examples

Detection Application	URL to Configure
LPR Camera 1	http://192.168.1.100:8080/liveview1
Parking Detector Zone A	http://192.168.1.100:8080/liveview2
Area Counter Entrance	http://192.168.1.100:8080/liveview3

Verification

To verify that detection applications are sending images correctly:

1. Start the Live View Interface application
2. Start the detection application(s)
3. Watch the Live View Interface display - images should appear within a few seconds
4. If no images appear, check:
   • Detection application is running and processing video
   • URL in detection application is correct
   • Both applications are on the same network
   • Firewall is not blocking the connection

8. Troubleshooting

Display Issues

Possible causes and solutions:

• Detection application not running: Start the detection application that should be sending images
• Wrong URL configured: Check that the detection application is configured with the correct URL to this Live View Interface
• Network connectivity: Verify both applications can communicate over the network
• Incorrect feed number: Ensure the detection application is sending to the correct endpoint (liveview1, 2, or 3)
• Port mismatch: Verify the port number in the URL matches the port in lv.ini

Possible solutions:

• Network bandwidth: Check if network bandwidth is sufficient for video transmission
• Detection application performance: The detection application may not be processing frames fast enough
• Reduce number of views: Set number_of_views to 2 or 1 to reduce display load
• Close other applications: Free up system resources by closing unused programs

Solution: This is normal behavior when the aspect ratio of the source video doesn't match the aspect ratio of the display area. The application maintains aspect ratio while fitting to the available space. You can try changing the layout (vertical/horizontal) to better match your source video dimensions.

Web Access Issues

Possible causes and solutions:

• Application not running: Ensure the Live View Interface application is running
• Wrong host binding: Change host in lv.ini from 127.0.0.1 to 0.0.0.0 for remote access
• Firewall blocking: Configure firewall to allow connections to the configured port
• Wrong URL: Use the correct format: http://ip:port/liveview1
• Port not accessible: Verify the configured port (default 8080) is not blocked

Solution: You may have reached the server but the URL path is incorrect. Use one of the valid endpoints: /liveview1, /liveview2, or /liveview3.

Configuration Issues

Solution: After modifying lv.ini, you must restart the Live View Interface application for changes to take effect.

Solution: These settings are read when the application starts. Close the application, edit the settings in lv.ini, then restart the application.

Network Issues

Checklist:

1. Is the Live View Interface application running?
2. Is the host IP correct in the URL?
3. Is the port number correct?
4. Is the firewall allowing traffic on the configured port?
5. Are both computers on the same network?
6. Can you ping the Live View computer from the detection application computer?

Performance Tips

• Limit displayed views: Set number_of_views to the minimum needed (1 or 2 instead of 3)
• Choose appropriate layout: Vertical layout for tall screens, horizontal for wide screens
• Increase threads if needed: If many web users are accessing simultaneously, increase maxThreads
• Close unused browser tabs: Web browsers consuming feeds use system resources