Tristan Penman's Blog


Here you’ll find write-ups of some of my long running projects.

Chromecast Deep Dive

2021 - 2023

This series is a deep-dive into the design and implementation of Google Cast, the protocol that powers Chromecast, as well as other devices in the Chromecast built-in ecosystem. The final result of this work is a working Google Cast Receiver, written in Go, which has now been published as the GoCast project on GitHub.

To write this series, I’ve pieced together information from various articles and open source projects, including Google’s Open Screen Library project.


The first part of this series has now been released:

The rest of the series will be released in the coming weeks, and I’ll update this list with links as they become available:

  • Part 2 - Chromecast Apps
  • Part 3 - Playing Video or Audio
  • Part 4 - Device Authentication
  • Part 5 - Screen Mirroring and Decryption
  • Part 6 - A Working Receiver in Go