OBS Studio is a cross-platform live streaming and recording application. Its architecture is modular: a core library (`libobs`) provides the runtime for sources, encoders, outputs, services, and filters, all registered via a plugin system. The frontend is a Qt-based desktop GUI (`frontend/`) that manages scenes, sources, audio mixing, and output controls. Graphics rendering is abstracted across Direct3D 11, Metal, and OpenGL backends. The system ingests video/audio from capture sources (screen, window, game, camera, hardware I/O like DeckLink), processes them through filters and encoders (x264, NVENC, QSV, AMF, FFmpeg), and outputs to streaming protocols (RTMP, WHIP, SRT) or local files (FLV, MP4, MOV). External dependencies include FFmpeg, Qt, libcurl, and various hardware SDKs. The codebase demonstrates strong engineering with reusable utility libraries (dynamic arrays, strings, config files, profilers) and a well-defined plugin API, though platform-specific code and bundled third-party SDKs introduce some technical drift.
XCap is a cross-platform screen capture library written in Rust, supporting Linux (X11, Wayland), macOS, Windows, and HarmonyOS (OHOS). It provides a unified API for capturing images of monitors and windows, as well as video recording (currently work-in-progress). The library abstracts platform-specific implementations behind common `Monitor`, `Window`, and `VideoRecorder` structs, using native APIs such as XCB, PipeWire, CoreGraphics, AVFoundation, GDI, Windows Graphics Capture, and OHOS PixelMap. It is well-structured with clean error handling and modular platform modules, though some features like Wayland capture and window recording are still incomplete. The codebase demonstrates solid Rust engineering practices and is actively maintained.
SysDVR is a Nintendo Switch homebrew streaming tool that captures the console's video and audio output and streams it to external clients via USB, TCP, or RTSP. The system comprises three main components: a sysmodule (C code) running on the Switch that interfaces with the grc:d service to capture frames and audio, a cross-platform client (C# .NET 9) that receives the stream, decodes it with FFmpeg, and renders/records using SDL2 and ImGui, and a configuration app (C++ ImGui) that runs on the Switch to manage streaming modes and patches. The architecture is modular with clear separation between capture, transport, and playback layers. The client uses a custom binary protocol with handshake, packet headers, and NAL replay for efficient streaming. External dependencies include libnx (Switch), FFmpeg, SDL2, libusb, ImGui, and .NET 9. The codebase demonstrates solid engineering with reusable patterns like buffer pools, pipeline chains, and platform abstraction, though it carries some technical debt from outdated third-party bindings and platform-specific workarounds.