MediaByteSource

Media bytes from caller code instead of a path: the custom I/O door. A player streams through its own HTTP client with its own TLS and auth, reads from an encrypted store, a torrent, a cache, or a byte array it already holds, and FFmpeg demuxes those bytes exactly as it would a file's.

Threading and blocking. Every call arrives on the thread driving the demuxer, one call at a time, never concurrently. read MUST block until it has at least one byte; a source with nothing more to give returns -1. Failures are thrown, not encoded: any exception from these methods surfaces to FFmpeg as an I/O error on the operation that triggered the call.

Lifetime. The MediaSource opened over this owns it: close runs exactly once when that source closes, and the instance must stay valid until then.