Dual HD server demo

This is an example server setup demonstrating real-time cropping of a Dual HD stream using Mediamtx.

What is Dual HD?

Dual HD is a video standard that contains both horizontal and vertical view within a single frame. Dual HD 2640, used in this example, contains Full HD (1920×1080) video for horizontal and 720p (720x1280) for vertical video.

Dual HD is designed for streaming across platforms like Twitch/YouTube (horzontal) and TikTok/Instagram (vertical).

For more on the Dual HD format, visit dualhd.org.

Purpose of this repository

This repo is useful for testing and demonstrating Dual HD and it provides a working example of:

• Simulating a Dual HD livestream from a PNG image to Mediamtx server using FFmpeg
• Automatically cropping the Dual HD video into horizontal and vertical outputs, that can be read via RTMP

Prerequisites

Docker Desktop (or Docker CLI + Docker Compose)

How to run this example

1. Clone this repository and start the server

docker compose up

This will start a MediaMTX server with routing rules for horizontal and vertical crops.

2. Simulate a live Dual HD stream

ffmpeg -loop 1 -framerate 30 -i dualhd2640.png \
    -c:v libx264 -preset veryfast -r 30 -f flv rtmp://localhost:1935/dualhd2640

This turns dualhd2640.png into a 30fps live stream.

3. Watch the output streams

You can view the output streams using VLC or similar software:

• Horizontal view: rtmp://localhost:1935/horizontal
• Vertical view: rtmp://localhost:1935/vertical