Minimal Embedded Linux OS for Video Streaming on Raspberry Pi 4b

📌 Project Overview

Wiki Overview Page

This project aims to create a custom, headless embedded Linux distribution using Buildroot for the Raspberry Pi 4b. The OS is designed to stream video from the Raspberry Pi Camera Module 2 with minimal resource usage (CPU, RAM, storage), in contrast to typical streaming setups like FFmpeg on Ubuntu.

🚀 Future Prospect: This base will eventually support a web-based dashboard for live video view, object tracking, and alert notifications.

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🎯 Objectives

• Build a minimal Linux OS using Buildroot.
• Enable compatibility with Raspberry Pi 4b hardware.
• Integrate drivers for the Raspberry Pi Camera Module 2.
• Capture and stream video efficiently over UDP using a custom C++ application.
• Benchmark performance against traditional full OS solutions.

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🛠️ Tools & Technologies

• Buildroot
• Linux Kernel
• Raspberry Pi 4b
• Camera Module 2 (Sony IMX219)
• libcamera
• BusyBox
• Custom C++ UDP streaming application
• UDP receiver/viewer utility (for desktop viewing)

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📁 Project Structure

project-root/

│

├── buildroot/ # Buildroot configuration and source along with the build files

├── raspi-stream/ # C++ camera and streaming application

├── core/ # Stores all core cpp modules and class definitions for camera utility ├── src/ # Contains the main application ├── streamer/ # Contains logic of the streaming applicaiton

├── stream-viewer/ # UDP receiver/viewer utility for desktop

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🚦 Project Status

Phase	Status
Buildroot setup	🟡 Complete
RPi4b bring-up	🔲 Complete
Camera integration	🔲 Complete
Streaming application	🟡 Complete
Performance validation	🔲 In progress

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📅 Scrum Plan

This project is broken into 3 major scrums:

1. Scrum 1: OS Bring-up

   • Minimal Buildroot config
   • Boot on RPi4b

2. Scrum 2: Camera Integration

   • Enable and test camera drivers
   • Capture sample frames

3. Scrum 3: Streaming & Optimization

   • Implement low-overhead streaming
   • Benchmark vs Ubuntu + FFmpeg

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🖥️ Streaming Application

• The main streaming application is written in C++ and uses libcamera to capture frames from the Pi Camera.
• Frames are sent over UDP using a custom Streamer class, which transmits all planes of each frame.
• The application supports resolution selection (720p, 1080p, 480p) via command-line arguments.
• Usage example: ./raspi-stream 720p <destination_ip> [port]
• Default port is 8554 if not specified.

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🖥️ UDP Receiver/Viewer

• A simple UDP receiver utility (udp-receiver.cpp) is provided for desktop use.
• It listens for incoming UDP packets, reconstructs YUV420 frames, and writes them to a file.
• Example usage: ./udp-receiver 5000 1280 720 out.yuv
• You can view the resulting file with ffplay: ffplay -f rawvideo -pixel_format yuv420p -video_size 1280x720 out.yuv

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📌 Future Extensions

• Web-based dashboard for stream viewing
• Object tracking (OpenCV / ML models)
• Alert system based on detected events
• WebSocket or MQTT-based backend integration

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📚 References

• Buildroot Documentation
• Raspberry Pi Camera Docs
• V4L2 API Reference
• Libcamera

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📜 License

This project is for academic and educational purposes.