Delta Play Replay

A (hobby) project to communicate with the gRPC api exposed by e.g. AoE2DE during replays and creating a specification and tooling for a new replay format *.dlpr for Age of Empires II: Definitive Edition (AoE2DE) and other games.

Background

The existing CaptureAge (CA) replay system utilizes an internal format (*.cars/*.carz) to play recorded games. This format supports backward compatibility with older recorded games, allowing them to be replayed without running the original AoE2DE simulation. However, the *.cars/*.carz formats are currently primarily designed for internal debugging purposes and in-memory use. It is not easily accessible to the broader community, and it is not clear if it's designed to be shared or stored for long periods.

The goal is to create a new, standardized replay format *.dlpr that accommodates the requirements for efficient storage, improved replay functionalities, and broader community support. Or in case, the original formats are already designed for long-term storage, to create a specification and tooling around it.

Goals

• create a specification and tooling around a delta-based replay format *.dlpr for AoE2DE, that doesn't break each new game engine version

• automate the conversion process of recorded games to this delta-based replay format from game engine versions since the release of AoE2DE

• implement a parser and create a package to be pulled in by node.js via https://neon-rs.dev/

• at the end there should be the possibility for others to implement a WebPlayer (CA in the browser) to replay recorded games from all game engine versions of AoE2DE since release (think of it like a Youtube for recorded games)

• the project should be open source and free to use for everyone (AGPL-3.0-or-later)

• check the requirements for more details

Optional Goals/Design Decisions

• is it viable, to make the delta-based replay format game independent

  • e.g., what if AoE4, AoM:R and AoE3DE would also have a gRPC Api. Should there be a one-fits-all format where the game is a property or should each game have their own standalone formats?

Non-goals

• reimplement a desktop tool like CaptureAge

• enable people to cheat by exposing information of live games, our effort is totally focussed on (stored) recorded games

  • exception: if the franchise would convert into the format server-side and stream it to CaptureAge directly to be able to spectate games without having the game engine running

Building

Prerequisites

• Build Tools for Visual Studio for msvc, clang, cmake, etc.
• Rust
• protobuf for protoc compiler (e.g. scoop install protobuf)
• perl for openssl-sys (e.g. scoop install perl)
• openssl for openssl-sys (e.g. scoop install openssl)

License

AGPL-3.0-or-later; see LICENSE.