A standalone implementation of the ChaCha20 stream cipher (RFC 7539) used for segment decryption. It is self-contained, has no external dependencies, and can be extracted and reused in any .NET project requiring ChaCha20 encryption/decryption. Demonstrates non-obvious skill in implementing cryptographic primitives correctly.

A recursive MP4 box parser that reads ISO Base Media File Format (ISOBMFF) structures. It handles nested boxes, large boxes, and provides a clean API for extracting specific box types (e.g., moov, trak, mdia). Reusable for any project that needs to parse MP4 files for metadata, encryption info, or subtitle tracks. The implementation is a direct translation from shaka-player but well-structured and testable.

A comprehensive utility for concatenating and muxing media files using FFmpeg or mkvmerge. Supports multiple concat modes (binary, FFmpeg protocol, demuxer, local HTTP server), handles multi-period DASH alignment, and provides progress reporting. The design abstracts external tool differences behind a single interface, making it reusable for any project that needs to combine media segments into a single file.

A seekable read-only stream that concatenates multiple file streams into one logical stream. It supports seeking, reading, and length queries, and is used to provide a virtual input file to FFmpeg. This pattern is reusable for any scenario where multiple files need to be treated as a single stream without copying data, such as in media processing or data pipelines.

A component that tracks downloaded segments during live recording to avoid duplicates across playlist refreshes. It uses URL, index, timestamp, and byte-range matching to identify already-downloaded segments. The design is generic and can be extracted for any live streaming application that needs to handle sliding window manifests and prevent redundant downloads.