NDI Remote Callers Guide

Configuration guide for integrating remote participants via NDI into the Multi-Camera Livestream Framework.

Last Updated: Version: 1.0.0

Table of Contents

  1. Overview
  2. NDI Fundamentals
  3. Caller Setup
  4. OBS NDI Integration
  5. Latency Optimization
  6. Multi-Caller Management
  7. Troubleshooting

Overview

NDI (Network Device Interface) allows remote participants to send high-quality video and audio over the network. This is ideal for:

  • Remote guests on the show
  • Off-site co-hosts
  • Screen sharing from remote locations
  • B-roll from remote cameras

NDI vs. Other Solutions

Method Latency Quality Complexity
NDI ~100-200ms Excellent Medium
Zoom/Discord 200-500ms Good Low
SRT 200-500ms Excellent High
WebRTC 100-300ms Variable Medium

NDI Fundamentals

How NDI Works

Remote Caller ──[NDI over LAN/WAN]──→ Mac Studio ──→ OBS
      │                                    │
    [NDI Source]                    [NDI Receiver]

NDI Requirements

For Remote Callers:

  • Wired Ethernet connection (strongly recommended)
  • Webcam or camera
  • NDI-compatible software
  • Upload bandwidth: 10+ Mbps (for 1080p)

For Your Studio:

  • Download bandwidth: 10+ Mbps per caller
  • NDI Tools installed
  • OBS with NDI plugin

NDI Software Options

Software Platform Cost Best For
NDI Webcam Input Win/Mac Free Simple webcam
OBS + NDI Plugin Win/Mac/Linux Free Full production
Skype + NDI Windows Free Easy setup
vMix Call Web-based Free Remote guests
NDI Screen Capture Win/Mac Free Screen sharing

Caller Setup

For Remote Callers Using OBS

  1. Install NDI Tools from ndi.tv
  2. Install OBS NDI Plugin from obs-ndi releases
  3. Configure OBS:
    • Tools → NDI Output Settings
    • Enable “Main Output”
    • Set Output Name (e.g., “Guest-John”)

For Callers Using NDI Webcam Input

Simplest option for basic video calls:

  1. Download NDI Webcam Input from NDI Tools
  2. Launch application
  3. Configure:
    • Select webcam
    • Set resolution (1080p recommended)
    • Name the source
  4. Share your IP address with the studio

Network Configuration for Remote NDI

Option 1: VPN (Recommended)

Remote Caller ──[VPN]──→ Studio Network ──→ Mac Studio

Option 2: NDI Bridge (For WAN)

Remote Caller ──[NDI Bridge/HX]──→ Internet ──→ Mac Studio

Option 3: Port Forwarding (Advanced)

  • Forward port 5960-5990 (TCP/UDP)
  • Not recommended for security reasons

OBS NDI Integration

Installing OBS NDI Plugin

  1. Download from obs-ndi releases
  2. Install the package
  3. Restart OBS
  4. Verify: Tools menu should show NDI options

Adding NDI Sources

  1. Sources → Add → NDI Source
  2. Configure:
    • Source Name: Descriptive name (e.g., “NDI-Guest-John”)
    • Source: Select from discovered NDI sources
    • Bandwidth: Highest (or adjust for network)
    • Sync: Network (recommended)
    • Latency Mode: Normal

NDI Source Settings

Source Name: NDI-Guest-John
Source: [Discovered NDI Source]
Bandwidth: Highest
Sync: Network
Allow hardware acceleration: ✓
Latency mode: Normal
PTZ: (disable unless using PTZ camera)

Audio Considerations

NDI sources include embedded audio. Options:

  1. Use NDI Audio: Enable audio in NDI source properties
  2. Separate Audio: Disable NDI audio, use dedicated audio path
  3. Mixed: Use NDI audio as backup, prefer dedicated audio

Latency Optimization

Reducing NDI Latency

Setting Impact Trade-off
Low bandwidth mode Reduces latency Lower quality
Disable HW acceleration More consistent Higher CPU
Sync: Network Better sync Slight delay
Dedicated VLAN Reduces jitter Network complexity

Network Optimization

For LAN:

  • Use gigabit Ethernet (not WiFi)
  • Dedicated NDI VLAN if possible
  • Enable jumbo frames (9000 MTU)
  • QoS for NDI traffic

For WAN:

  • Use NDI HX (compressed) instead of NDI (full bandwidth)
  • VPN for security
  • Stable upload connection for callers
  • Buffer for jitter (increase latency slightly)

Measuring Latency

In OBS:

  1. View → Stats
  2. Check “Average frame render time”
  3. Monitor for dropped frames

Test latency:

  1. Display timecode on caller end
  2. Capture with OBS
  3. Compare displayed vs captured time

Multi-Caller Management

Organizing Multiple Callers

Create a consistent naming scheme:

NDI Source Name OBS Source Name Guest
GUEST-01 NDI-Guest-Alice Alice
GUEST-02 NDI-Guest-Bob Bob
GUEST-03 NDI-Guest-Carol Carol

Scene Templates for Callers

Scene: Single Caller
└── NDI-Guest-Current (full screen)

Scene: Two Callers
├── NDI-Guest-1 (left 50%)
└── NDI-Guest-2 (right 50%)

Scene: Three Callers
├── NDI-Guest-1 (top left)
├── NDI-Guest-2 (top right)
└── NDI-Guest-3 (bottom center)

Scene: Host + Caller PIP
├── CAM-Host (full screen)
└── NDI-Guest-Current (corner PIP)

Caller Onboarding Checklist

Send to callers before the show:

  • Install NDI Tools
  • Configure webcam/camera
  • Test audio levels
  • Connect via VPN (if required)
  • Send NDI source name to studio
  • Test connection 30 min before show
  • Wired Ethernet connected
  • Background/lighting acceptable

Pre-Show Caller Test

  1. Have caller enable NDI output
  2. Verify source appears in OBS NDI list
  3. Add to test scene
  4. Check video quality
  5. Check audio levels
  6. Test latency (clap test)
  7. Confirm backup communication method (phone/Discord)

Troubleshooting

NDI Source Not Appearing

Symptoms: Remote NDI source not visible in OBS

Solutions:

  1. Verify both devices on same network/subnet
  2. Check firewall settings (allow NDI ports 5353, 5960-5990)
  3. Restart NDI services on caller end
  4. Refresh NDI sources in OBS (may take 30-60 seconds)
  5. Verify NDI Tools are running on both ends

Poor Video Quality

Symptoms: Pixelation, compression artifacts

Solutions:

  1. Increase bandwidth setting in OBS NDI source
  2. Check caller’s upload speed
  3. Switch to NDI HX if network is constrained
  4. Reduce caller’s output resolution
  5. Check for network congestion

Audio Out of Sync

Symptoms: Lip sync issues with NDI caller

Solutions:

  1. In OBS, right-click NDI source → Advanced Audio Properties
  2. Adjust Sync Offset (typically +/- 100ms)
  3. Try different Sync mode (Network vs Internal)
  4. Use separate audio source with manual sync

High Latency

Symptoms: Noticeable delay when talking to caller

Solutions:

  1. Use NDI HX instead of full NDI
  2. Enable “Low bandwidth” in NDI source
  3. Check for network hops between caller and studio
  4. Consider alternative (WebRTC may have lower latency for some setups)

Dropped Frames from NDI

Symptoms: OBS shows dropped frames from rendering

Solutions:

  1. Reduce number of simultaneous NDI sources
  2. Lower NDI source resolution
  3. Check CPU usage (NDI decoding is CPU-intensive)
  4. Enable hardware acceleration if available
  5. Consider M1’s limited NDI hardware acceleration

Connection Drops

Symptoms: NDI source disconnects intermittently

Solutions:

  1. Check caller’s network stability
  2. Increase network timeout settings
  3. Use wired connection (not WiFi)
  4. Check for VPN disconnections
  5. Have backup communication channel ready

Quick Reference

NDI Ports

Port Protocol Purpose
5353 UDP mDNS discovery
5960-5990 TCP/UDP Video transport

OBS NDI Source Cheat Sheet

Best Quality:    Bandwidth=Highest, Sync=Network, HW Accel=On
Lower Latency:   Bandwidth=Lowest, Sync=Internal, Latency=Low
Balanced:        Bandwidth=High, Sync=Network, Latency=Normal

Caller Quick Setup Email Template

Subject: NDI Setup for [Show Name] - [Date]

Hi [Caller Name],

Please complete these steps before our show:

1. Install NDI Tools: https://ndi.tv/tools/
2. Open NDI Webcam Input (or your NDI app)
3. Set your source name to: GUEST-[YourName]
4. Connect to VPN: [VPN instructions if applicable]
5. Test at [time] - I'll confirm I can see your source

Technical requirements:
- Wired Ethernet connection
- Webcam at 1080p
- Upload speed: 10+ Mbps
- Quiet, well-lit environment

Backup contact: [phone/Discord]

Let me know if you have questions!

See Also

Document maintained by Multi-Camera Livestream Framework team