cap-camera-mediafoundation

Ergonomic Rust wrapper around Windows Media Foundation API for camera capture, providing safe abstractions while maintaining low-level control. Aims to mirror how Chromium consumes Media Foundation.

Purpose

Provides safe access to Windows camera devices through Media Foundation's Capture Engine, handling COM initialization, device enumeration, format negotiation, and asynchronous frame delivery.

Key Features

• Device Discovery: DeviceSourcesIterator for enumerating video capture devices
• Format Enumeration: Access to native media types supported by each device
• Asynchronous Capture: Channel-based frame delivery via CaptureHandle
• Memory Safety: RAII buffer locking with IMFMediaBufferExt trait
• Error Handling: Comprehensive error types and retry logic for Media Foundation timing issues

Core APIs

Device Management

• initialize_mediafoundation() - Initialize MF subsystem
• DeviceSourcesIterator::new() - Enumerate available cameras
• Device::name(), Device::id(), Device::model_id() - Device metadata
• Device::formats() - Iterator over supported IMFMediaType formats

Capture Pipeline

• Device::start_capturing(format) - Begin async capture with specified format
• CaptureHandle::sample_rx() - Receive IMFSample frames via channel
• CaptureHandle::event_rx() - Receive CaptureEngineEvent status updates

Frame Processing

• VideoSample::bytes() - Extract frame data as byte array
• IMFMediaBufferExt::lock() - Safe buffer access with automatic unlock

Architecture

Bridges Media Foundation's callback-based model to Rust's ownership system using channels for cross-thread communication, RAII for resource management, and comprehensive error handling for production reliability.