transmux 0.1.0

MPEG-2 TS → CMAF/fMP4 remux: typed ISOBMFF boxes, a samples-in init/media segment builder, Annex B ↔ length-prefixed NAL, and HLS playlist generation (ISO/IEC 14496-12, RFC 8216).
Documentation

transmux — MPEG-2 TS → CMAF/fMP4 remux

Container-layer remux from MPEG-2 Transport Stream to fragmented MP4 / CMAF, built to spec (ISO/IEC 14496-12:2015, RFC 8216). Samples-in: the caller supplies demuxed encoded access units + codec config; transmux produces the initialization and media segments (and the HLS playlists). No transcode, no codec bitstream decoding. no_std + alloc.

What's in the box

Layer Types
ISOBMFF boxes Box/FullBox framing, MovieBox tree (mvhd/trak/tkhd/mdia/minf/stbl/stsd), mvex/trex, movie-fragment boxes (moof/mfhd/traf/tfhd/tfdt/trun), ftyp/styp/mdat, timing boxes (stts/ctts/stsc/stsz/stco/elst/sidx)
Codec config avcC/hvcC decoder-configuration records, esds/ES_Descriptor, AAC AudioSpecificConfig (+ ADTS)
NAL Annex B ↔ length-prefixed conversion (annexb_to_length_prefixed / length_prefixed_to_annexb)
Pipeline build_init_segment (ftyp + fragmented-init moov) and build_media_segment (styp + moof + mdat) from a TrackSpec / Sample samples-in API
Packaging HLS media + master playlist generation (MediaPlaylist / MasterPlaylist, RFC 8216)

Every box has a symmetric Parse / Serialize with byte-identical round-trip coverage against real fMP4 fixtures.

Quick start

use transmux::{build_init_segment, build_media_segment, CodecConfig, TrackSpec,
               Sample, FragmentTrackData};

// Describe each track (codec config synthesised by the caller from SPS/PPS, ADTS…).
let tracks: Vec<TrackSpec> = /* … */ Vec::new();
let init = build_init_segment(&tracks, 1000)?;         // ftyp + moov

// Feed samples per fragment.
let video: Vec<Sample> = /* … */ Vec::new();
let media = build_media_segment(1, &[FragmentTrackData {
    track_id: 1,
    base_media_decode_time: 0,
    samples: &video,
}])?;                                                  // styp + moof + mdat
# Ok::<(), transmux::Error>(())

An end-to-end tests/ts_to_cmaf.rs demonstrates the full path: demux a real H.264+AAC TS, synthesise avcC/esds, and emit byte-identical-config CMAF segments.

Scope

transmux is the container layer only. Demux (TS → elementary streams) and transcode live in the caller. It is a clean-room, spec-built alternative to ripping a C muxer — every layout cites ISO/IEC 14496-12.

License

MIT OR Apache-2.0.