vswhere is a command-line utility developed by Microsoft to locate installed instances of Visual Studio and related products (Build Tools, etc.). It queries the Visual Studio Setup Configuration API (ISetupConfiguration) and the Windows Registry to discover installation paths, versions, and workloads. The tool supports filtering by version range, product ID, workload requirements, and legacy installations. Output can be formatted as text, JSON, XML, or raw values, making it suitable for build scripts and deployment automation. The architecture consists of a core static library (vswhere.lib) containing the logic for parsing, querying, and formatting, linked against a minimal executable entry point (vswhere.exe). It relies on COM interfaces for setup configuration and standard C++17 libraries for string and filesystem operations.
LAVFilters is a mature Windows DirectShow filter suite for media playback. It consists of three COM-registered filters: LAV Splitter (a demuxer/source filter), LAV Audio Decoder, and LAV Video Decoder. The splitter wraps FFmpeg's libavformat to read virtually any container, while the decoders use FFmpeg's libavcodec plus hardware acceleration backends (DXVA2, D3D11VA, NVIDIA CUVID, Intel QuickSync) and expose property pages and programmatic COM settings interfaces. The code is predominantly C++ with heavy use of DirectShow base classes, COM plumbing, and low-level SIMD pixel-conversion routines.