NDI Bridge Deployment
Introduction
NDI Bridge is a powerful tool that enables secure, high-quality transmission of NDI® signals between remote locations over public internet. It extends the flexibility of the NDI ecosystem beyond the local network, providing a robust method for bridging geographically distributed production environments.
This deployment guide is intended for technical users, system integrators, and IT professionals responsible for setting up and maintaining IP-based media workflows. It provides detailed instructions and best practices for deploying NDI Bridge in Local and Remote modes.
Key capabilities include:
End-to-end encrypted multi-point transport of NDI streams over public networks.
Low-latency, high-fidelity audio, video, and metadata transmission, maintaining the user experience of NDI workflows over WAN.
Support for NDI Grouping.
Transparent transport of bi-directional metadata
Flexible configuration options include customizable port and audio/video compression settings.
NDI Bridge is ideal for scenarios such as:
Connecting production teams across cities or countries.
Sharing NDI sources between broadcasters, post-production studios, or live event venues.
Acting as a stream repeater or relay to simplify NDI signal distribution, especially in networks where multicast is not available or not desirable.
Whether you're deploying NDI Bridge in a controlled LAN or across challenging WAN environments, this guide will help you set up a reliable and secure connection, tailored to your specific technical requirements.
System Requirements
To ensure optimal performance and stability, the following system requirements must be met when deploying NDI Bridge.
Hardware Requirements
NDI Bridge relies on CPU and GPU resources to manage the encoding and transmission of multiple NDI streams in real time. While it can run on most modern systems, optimal performance is achieved on workstations or servers specifically configured for video processing.
A dedicated GPU is required, either Intel Quick Sync Video (available on most recent Intel CPUs with integrated graphics) or an NVIDIA GPU that supports hardware-accelerated video encoding (NVENC). The number of simultaneous streams NDI Bridge can handle effectively depends on the number of available hardware encoders on the installed GPU.
Systems with discrete NVIDIA GPUs (such as the Quadro or RTX series) generally support more concurrent hardware-accelerated encodes than systems relying solely on integrated graphics. Professional-grade GPUs are especially well-suited for handling multiple simultaneous streams efficiently, offering greater scalability and performance.
A modern multi-core CPU (6 cores or more) is recommended to support overall system responsiveness and coordination between network, disk, and GPU operations.
At least 16 GB of RAM is advisable, especially when handling multiple streams or running other NDI tools alongside Bridge.
A wired Ethernet connection is strongly recommended to ensure stable and consistent performance, especially in professional environments. However, NDI Bridge can function over Wi-Fi if needed, provided the network is reliable and has sufficient bandwidth.
Operating System Compatibility
NDI Bridge is available for the following platforms:
Windows 10/11 (64-bit)
Windows Server 2016 or later
Connectivity
NDI Bridge HOST requires a public IP address and a properly configured Port Forwarding (default: 5990)
What Is Port Forwarding?
Port forwarding allows external devices to access services on your local network by directing traffic through specific ports on your router to designated devices. This is essential for applications like NDI Bridge that require incoming connections from the internet.
General Steps for Port Forwarding
Access Your Router's Web Interface:
Open a web browser and enter your router's IP address (commonly 192.168.0.1 or 192.168.1.1).
Log in with your admin credentials
Navigate to Port Forwarding Settings:
Look for sections labeled Port Forwarding, Virtual Server, or NAT Forwarding.
Create a New Port Forwarding Rule:
Service Name: Assign a name (e.g., NDI Bridge).
Internal IP Address:
Enter the IP of the device running NDI Bridge (e.g., 192.168.1.100).
Internal Port:
Specify the port used by NDI Bridge (e.g., 5990).
External Port:
Usually the same as the internal port.
Protocol:
Choose both TCP and UDP
Status:
Enable the rule.
Save and Apply Changes:
Save the configuration and reboot the router if necessary.
Test the Port Forwarding:
Run NDI Bridge and perform the port verification:
Public IP and Port Verification
NDI Bridge can automatically detect and display the network's public IP address and indicate whether port forwarding is correctly configured.
Best Practices
Static IP: Assign a static IP to the NDI Bridge device to prevent IP changes.
Firewall Configuration: Ensure your firewall allows traffic through the specified ports.
Avoid Conflicts: Ensure other services do not use the chosen ports.
NDI Groups support
NDI Groups are a mechanism within the NDI® ecosystem that allows users to control the visibility and access of NDI sources across a network. Rather than exposing all available NDI streams to every device, groups allow systems to publish and discover sources based on logical grouping selectively.
Each NDI device can be assigned to one or more groups via configuration. Only sources within the same group will be visible to each other. Isolating streams helps organize large environments, reduce unnecessary network traffic, and improve security.
NDI Bridge allows users to control which NDI sources are shared with remote endpoints by using NDI Groups. This provides precise management over stream visibility, especially in wide-area or multi-site deployments.
When configuring NDI Bridge, the user has two options for managing group-based access:
Manual Group Selection in NDI Bridge
Users can explicitly define which NDI Group(s) should be available to remote NDI Bridge instances within the application interface. Multiple groups can be specified by separating their names with commas. Only the sources belonging to the defined group(s) will be published to the remote side.
Using NDI Access Manager Settings
Alternatively, NDI Bridge can rely on the existing NDI Group configuration set at the system level through NDI Access Manager. This is useful in environments where group policies are centrally managed or must be consistent across multiple applications and systems.
Accessing the Encoding Settings Panel
In NDI Bridge, encoding settings can be configured through a dedicated panel accessible directly from the application's main interface.
To open the encoding configuration:
Locate the gear icon (⚙️) in the top-right corner of the NDI Bridge interface.
Click the icon to open the Settings panel.
Within this panel, navigate to the Encoding section to adjust compression and bandwidth-related parameters.
Check Compatibility
The Check Compatibility function is the first option available in the NDI Bridge encoding settings panel. It lets users verify whether the necessary system codecs are installed to support H.264 and HEVC (H.265) encoding and decoding.
This check is particularly important because the availability of these codecs depends on the version of the Windows operating system in use:
Windows 11: Both H.264 and HEVC codecs are pre-installed and available by default.
Windows 10 and earlier: While H.264 support is typically available, HEVC decoding requires the HEVC Video Extensions to be manually installed. These can be obtained via the Microsoft Store.
If the required codecs are not present, NDI Bridge may not be able to perform hardware-accelerated encoding or decoding, and certain stream formats may be unavailable. The Check Compatibility tool provides a quick way to ensure the system meets all codec prerequisites before establishing a remote NDI connection.
Output Settings
The Output section within the Encoding panel defines how NDI Bridge transcodes and prepares NDI streams for transmission to remote endpoints. These settings affect both video and audio compression, bandwidth usage, and overall stream compatibility.
Transcoding Format
The first option allows users to select the transcoding format, which determines how incoming NDI streams are processed before being sent remotely. The available options are:
NDI HX Transcodes each stream using a compressed format, suitable for lower bandwidth connections. Requires selection of a video codec (H.264 or HEVC).
NDI High Bandwidth Converts all incoming streams into full-bandwidth NDI format, using intra-frame compression. This setting does not require codec selection.
Do Not Transcode Acts as a pass-through: streams are sent exactly as received, without any modification or compression. No encoding settings are applied.
Encoder Selection
When NDI HX is selected as the transcoding format, a drop-down menu appears to choose between the following video codecs:
H.264 – Widely compatible, efficient compression.
HEVC (H.265) – Offers better compression efficiency and supports 10-bit video. Requires system support for HEVC encoding.
Audio Codec Behavior
When NDI HX is selected, audio is transcoded using the OPUS codec, which supports up to 255 audio channels per stream.
If a stream contains more than 255 channels, OPUS is automatically bypassed, and the audio is transmitted in its original format (typically PCM if the source is NDI High Bandwidth).
GPU Selection
NDI Bridge allows users to select which GPU should be used for hardware-accelerated encoding when using NDI HX (H.264/HEVC). This configuration is found in the Output Settings panel under the Encoding section.
Available Options:
Auto When set to Auto, NDI Bridge will automatically use any available compatible GPU (NVIDIA or Intel) on the system. It dynamically distributes the encoding workload across all detected GPUs, which is useful in multi-GPU systems.
Specific GPU Users can manually select a specific NVIDIA or Intel GPU for encoding.
Only Intel (Quick Sync Video) and NVIDIA (NVENC) GPUs are supported for hardware encoding.
NDI 4 Compatibility Mode
This option enables compatibility with receivers that do not support OPUS audio, which was introduced in NDI 5. When enabled, Bridge replaces OPUS with AAC audio for maximum compatibility with older devices.
Recommended if your receiving endpoint is running NDI 4 or earlier.
Bitrate Configuration
When using NDI HX, users can define the average bitrate used by the encoder. This setting allows balancing quality and bandwidth consumption depending on the available network capacity.
Statistics Panel
The Statistics Panel in NDI Bridge monitors system performance, network activity, and GPU usage, helping users diagnose issues and optimize system behavior during operation.
Network Metrics (Charts)
Send Bps Displays the current outgoing bitrate in megabits per second. This shows how much data is sent from the local Bridge instance to the remote endpoint(s).
Receive Bps This displays the incoming bitrate in megabits per second, which represents the volume of data being received from remote NDI sources.
RTT (Round Trip Time) Measures the latency between the local and remote NDI Bridge endpoints in milliseconds. A stable, low RTT is essential for real-time media workflows.
Packet Loss This indicates the number of lost packets over the last 60 seconds. Persistent packet loss may indicate network instability or bandwidth saturation.
System Metrics (Right Sidebar)
CPU / Memory Usage It shows the current CPU and RAM utilization of the host system, which is useful for identifying performance bottlenecks.
Bridge GPU / System GPU Displays GPU usage separately for:
GPU Encode
GPU Decode
3D Compute
This helps distinguish between resources used directly by NDI Bridge and those used by other applications or the operating system.
Buffer Displays the size of the receiving buffer in milliseconds. A larger buffer may help compensate for jitter or packet delay but can increase latency.
Send / Receive Rates Real-time indication of the current send and receive bandwidth in bits per second.
Packet Lost A repeat of the packet loss metric for quick visibility.
RTT Repeated display of round-trip time for convenience.
Up Time Indicates how long NDI Bridge has been running continuously.
GPU Activity (Charts)
Bridge GPU Graphs the encoding, decoding, and 3D processing activity of the GPU resources used specifically by NDI Bridge. This is useful for verifying that hardware acceleration is functioning.
System GPU It shows the total GPU load on the system, including applications outside of NDI Bridge. This helps assess whether the overall GPU capacity is sufficient.
Note on GPU Usage Statistics in NDI Bridge
When using Windows 10 or Windows 11, users may notice a discrepancy in how GPU usage is reported in the NDI Bridge statistics panel, depending on the selected graphics adapter and encoding format.
Observed Behavior:
When selecting an NVIDIA GPU, the NDI Bridge interface correctly shows activity in the "Video Encode" section while transcoding H.264 or HEVC streams.
However, when selecting an Intel GPU (e.g., Intel UHD Graphics P630), the interface may incorrectly show usage under "Video Decode", even though the encoder is being used.
Why This Happens:
This is due to a known limitation in the Windows GPU performance APIs, particularly how Windows Task Manager and related system APIs label GPU workloads. On some Intel GPUs, hardware encoding activity is misclassified as decoding, or reported under a different engine (e.g., 3D or Copy), depending on the driver and OS version.
This is purely a visual/reporting issue and does not indicate that encoding is failing or being done by the CPU. NDI Bridge still uses the selected hardware encoder correctly; only the system’s internal GPU telemetry reports it inaccurately.
Log Panel
The Log Panel in NDI Bridge provides a real-time, filterable view of system events, operational statuses, and diagnostic information across various internal services. It is an essential tool for monitoring system behavior, troubleshooting, and verifying the state of network connections and stream handling.
Main Features
Auto Scroll Button When enabled, the log view automatically scrolls to show the latest incoming log entries in real time.
Filter Button Opens or collapses the filter bar, allowing users to fine-tune which log entries are displayed based on severity, type, or system component.
Export Button Allows the entire log view to be saved as a file for external analysis or support purposes.
Filter Options
Users can filter log entries by three main categories:
Level Indicates the severity or importance of the message:
Information General runtime updates and status reports.
Warning Non-critical issues or abnormal conditions.
Error Failures that require user attention.
Critical Serious faults that may impact functionality.
Type
General Standard operational logs.
Data Over Time Enables the graphical performance view at the bottom of the panel.
Facility
Defines the subsystem responsible for generating the log entry:
ProxyHX Handles the encoding/transcoding and stream relaying processes.
VPN Manages remote client connections, bandwidth, RTT, and related metrics.
NDI Discovery Service Involved in local and remote NDI source/service discovery.
Log Export Formats
NDI Bridge can export runtime logs in both TXT and JSON formats. While both contain the same event data, each format serves different user needs.
TXT Format
The .txt log file is a human-readable format, ideal for quick reviews or sharing with support teams. Each log entry includes:
A timestamp (date and time in UTC format)
The log level (e.g., Information, Warning)
The module/facility that generated the message (e.g., ProxyHX, VPN)
A descriptive message, including metrics such as:
GPU usage
Audio/video buffer delay
Bandwidth and RTT statistics
Join/connection events
This format is ideal for visual inspection or copying documentation or email reports.
JSON Format
The .json file stores logs in a structured data format, useful for:
Automated parsing
Integrating with log analysis systems
Custom dashboards or monitoring tools
Each entry includes detailed fields:
Timestamp: in UTC and ISO 8601 format
Log Level: numeric level indicator
Facility: the subsystem (e.g., VPN, ProxyHX)
Message: the full log message
Additional fields like Event Id, Exception, and Type for programmatic filtering
Example:
"Message": "[VPN] [ I ][17:08:04.933] [Reflector Host] Video buffer delay usage for Client..."
Local Mode Overview
NDI Bridge can operate in Local Mode to enhance and optimize NDI workflows within the same local area network (LAN). This mode is particularly useful in two main scenarios:
Transcoding for Lightweight Distribution
Local Mode enables real-time transcoding to NDI HX using either H.264 or HEVC codecs when working with NDI High Bandwidth sources. This reduces the overall network load, making it ideal for lower-capacity or constrained networks.
Additionally, Local Mode can convert NDI High Bandwidth streams into NDI HX to ensure compatibility with receivers that only support NDI HX, such as specific hardware-based decoders or lightweight devices that do not support full-bandwidth NDI.
This functionality allows a single NDI Bridge node to act as a bandwidth reducer and a format translator within the LAN.
Unicast Stream Repeating (Unicast Repeater)
NDI uses unicast by default, which means each receiver adds load to the source’s network interface. This can quickly become a bottleneck when many devices subscribe to the same stream.
In Local Mode, NDI Bridge can act as a stream repeater, taking a single unicast stream from a source and redistributing it to multiple receivers.
Select the "Do Not Transcode" option in the Encoding Settings to do this.
Bridge will then forward the original stream without modification, bypassing encoder load and preserving quality.
This approach overcomes the original sender's unicast output limitation, leveraging the bridge host's network and system capacity to serve additional clients.
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