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Desktop Capture

Overview​

Desktop Capture allows ITVDesk to stream one or more computer monitors (desktops) as video channels of a virtual ONVIF IP camera.

This is commonly used for:

  • Control rooms
  • Operator workstations
  • Remote monitoring
  • Screen recording and auditing
  • Training and demonstration systems

ITVDesk supports single-monitor and multi-monitor desktop capture and can expose them as multiple ONVIF video channels or as separate virtual IP cameras, depending on your system and NVR/VMS capabilities.

Desktop capture selection

Selecting Desktop Capture​

To enable desktop capture:

  1. Create a new Virtual ONVIF IP Camera
  2. In Camera Media Source, enable Computer Screen Live
  3. Select one or more available monitors
  4. Confirm the selection

Each selected monitor becomes a video input source.

Desktop capture selection

Multiple Monitors and Channel Creation​

When multiple monitors are selected, ITVDesk can handle them in two different ways, depending on the capabilities of your NVR/VMS or RTSP/ONVIF client and the desired video channel structure.

tip

Terminology:

  • NVR (Network Video Recorder) – A device or software that records video streams from IP cameras.
  • VMS (Video Management System) – Software used to manage, view, record, and search video from IP cameras and ONVIF devices.
  • RTSP player – Any application capable of playing RTSP streams (for example VLC, FFplay, or similar tools).

If you do not use a third-party VMS or NVR, you can view and manage all ITVDesk streams using the ITVDesk VMS Client application, which supports ONVIF and RTSP playback out of the box.

Mode 1 – Multiple Channels (Single ONVIF Device)​

In Multi-Channel mode, ITVDesk exposes one ONVIF IP camera with multiple video channels.

  • Each monitor = one ONVIF video channel
  • All channels belong to the same ONVIF device
  • Ideal for NVR/VMS systems that support ONVIF multi-channel devices (e.g. ONVIF Profile S / multi-profile devices)

Example​

If the system has:

  • 2 monitors
  • 3 webcams

ITVDesk appears as:

  • 1 ONVIF IP camera
  • 5 video channels
    • Channel 1–2: monitors
    • Channel 3–5: webcams

This creates a single logical device with multiple video outputs.

When to Use Multi-Channel Mode​

  • Your NVR/VMS supports ONVIF devices with multiple channels
  • You want all video sources grouped under one device
  • Easier device management and cleaner device list

Mode 2 – Multiple Cameras (Single Channel per Camera)​

In Multiple Camera mode, ITVDesk creates one virtual ONVIF IP camera per video source.

  • Each monitor = one ONVIF device
  • Each device has exactly one video channel
  • All devices use the same IP address
  • Each device uses a different ONVIF port

This mode is designed for compatibility with NVR/VMS systems that do not support multi-channel ONVIF devices.

Example​

If the system has:

  • 2 monitors
  • 1 webcam

ITVDesk appears as:

  • 3 ONVIF IP cameras
    • Camera 1 → Monitor 1 (port 7000)
    • Camera 2 → Monitor 2 (port 7001)
    • Camera 3 → Webcam (port 7002)

Each camera has exactly one video channel.

When to Use Multiple Camera Mode​

  • Your NVR/VMS supports only single-channel ONVIF cameras
  • The system cannot handle ONVIF multi-profile or multi-channel devices
  • You want maximum compatibility

Key Difference: Channels vs Cameras​

FeatureMulti-ChannelMultiple Cameras
ONVIF devices1Multiple
Channels per deviceMultiple1
IP address11
Ports used1Multiple
NVR compatibilityRequires multi-channel supportWorks everywhere

Performance Considerations​

ITVDesk is optimized for CPU-based multi-threaded processing, which provides the most stable and predictable performance for desktop and application capture.

  • Each captured monitor or video source is processed independently
  • Video encoding runs in parallel using a multi-threaded CPU architecture
  • CPU usage depends on:
    • Output resolution
    • Frame rate (FPS)
    • Number of active monitors or sources
    • Selected video codec (H.264 / H.265 / MJPEG)

GPU Usage​

For desktop and application capture, ITVDesk primarily uses the CPU. Extensive testing has shown that GPU acceleration does not provide significant performance benefits for screen capture scenarios and may introduce additional latency or complexity.

GPU acceleration is used selectively for:

  • Decoding media files (e.g. MP4, H.264/H.265 files)
  • External media sources where hardware decoding is beneficial

This design ensures:

  • Stable performance on servers and workstations
  • Predictable resource usage
  • Reliable operation in multi-monitor and multi-channel environments

Recommendation​

For multi-monitor setups:

  • A modern multi-core CPU is the most important factor for performance
  • Increasing CPU core count scales better than relying on GPU acceleration
  • Hardware acceleration is optional and mainly relevant for media file decoding

Summary​

Desktop Capture in ITVDesk allows:

  • Capturing one or multiple monitors
  • Exposing them as multiple ONVIF channels or multiple ONVIF cameras
  • Seamless integration with both modern and legacy NVR/VMS systems

ITVDesk is one of the first applications that allows mixing multiple channels and multiple virtual IP cameras within the same system, providing maximum flexibility for real-world deployments.

Next Steps​

👉 Application Window Capture
👉 Webcam
👉 Combined Media Stream

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