use ;
/// Container format for frame timestamp encoding and frame payload structure.
///
/// - "legacy": Uses QUIC VarInt encoding (1-8 bytes, variable length), raw frame payloads.
/// Timestamps are in microseconds.
/// - "cmaf": Fragmented MP4 container - frames contain complete moof+mdat fragments.
/// Timestamps are in timescale units.
///
/// JSON example:
/// ```json
/// { "kind": "cmaf", "timescale": 1000000, "trackId": 1 }
/// ```