//! Subtitle-stream descriptor vocabulary — format + track origin.
//!
//! Two orthogonal axes describing a subtitle track:
//!
//! - [`Format`] — the file / demuxer-tag form (`"srt"` /
//! `"webvtt"` / `"ass"` / image-based `"hdmv_pgs_subtitle"` / …).
//! Distinct from [`crate::codec::SubtitleCodec`]: the *format* is
//! how the bytes are packaged on disk, the *codec* is how they
//! are encoded.
//! - [`TrackOrigin`] — where the bytes came from
//! ([`TrackOrigin::Embedded`] inside the container,
//! [`TrackOrigin::Sidecar`] file next to it, or
//! [`TrackOrigin::External`] download / OCR / ASR).
//!
//! Both types are pure media-stream descriptor vocabulary; they have
//! no per-cue / per-event content. The corresponding wire impls live
//! in [`crate::buffa`] behind the `buffa` feature.
pub use Format;
pub use TrackOrigin;