IETF Draft Defines MPEG-2 Transport Stream Packaging for Media Over QUIC Transport

The IETF Media Over QUIC (MOQ) working group published Internet-Draft draft-gregoire-moq-msfts-00 on May 6, 2026, authored by Paul Gregoire of Red5 and Gwendal Simon of Synamedia. The draft extends the MOQT Streaming Format (MSF) to register the "m2ts" packaging value, enabling direct carriage of MPEG-2 Transport Stream (TS) and M2TS source packets over Media Over QUIC Transport (MOQT).

MOQT is the IETF's standardized approach to media delivery over QUIC, the UDP-based transport protocol that powers HTTP/3. QUIC reduces head-of-line blocking compared to TCP, supports faster connection establishment, and includes congestion control tailored for lossy networks, making it well-suited for live media where low latency and reliability are critical. The MOQT transport specification defines delivery of named tracks as ordered groups of objects, while the MOQT Streaming Format (MSF) provides a catalog model and common conventions for describing tracks, including packaging formats for media payloads.

MPEG-2 TS remains the dominant container for broadcast contribution feeds, cable and satellite television, IPTV, and many over-the-top (OTT) streaming workflows. HLS, for example, uses MPEG-2 TS segments for video and audio delivery. Nearly all live media production pipelines output packetized MPEG-2 TS, from camera contribution feeds to broadcast playout systems. Before this draft, MSF did not include a packaging option for MPEG-2 TS, meaning organizations adopting MOQT would have to repackage TS into another format, such as fragmented MP4 or raw elementary streams, adding processing steps, latency, and potential points of failure. This draft eliminates that friction by mapping existing TS packets directly into MOQT objects.

The draft specifies that each MOQT object payload must be a concatenation of one or more whole source packets, with strict prohibition on splitting packets across objects. Source packets can be either standard 188-octet MPEG-2 TS packets, or 192-octet M2TS packets that prefix each TS packet with a 4-octet source-packet timestamp. The draft does not define new TS syntax, preserving all existing transport stream features including Program Association Tables (PAT), Program Map Tables (PMT), Program Clock References (PCR), Presentation Time Stamps (PTS), and conditional access scrambling.

Ten new fields are defined for MSF track objects using m2ts packaging. These include m2tsPacketSize (188 or 192 octets), m2tsPacketsPerObject (advisory count of packets per MOQT object), m2tsProgramNumber (identifies the MPEG-2 program carried by the track), m2tsPmtPid and m2tsPcrPid (advisory PIDs for PMT and PCR), m2tsPsiInterval (maximum interval for PSI repetition), m2tsRandomAccess (indicates if every group starts with a random access point), m2tsTimestampMode (interpretation of M2TS 4-octet timestamps), m2tsScte35Pid (PID for splice signaling), and initData (Base64-encoded initial PAT/PMT packets).

The draft recommends that tracks carry at most one MPEG-2 program, with publishers filtering multi-program transport streams (MPTS) into separate tracks per program. PAT packets must be rewritten to list only the program present in the track, and null packets may be removed or retained at the publisher's discretion. For alternate bitrate renditions (ABR), tracks use the MSF altGroup field, with group boundaries aligned across tracks to support clean switching between renditions. The draft notes that PID assignments and continuity counters do not need to match across alternate tracks, but receivers must re-parse PAT and PMT after switching, and treat the switch as a PCR discontinuity.

For live streams, publishers should start new MOQT groups at independently decodable points, such as IDR frames for video. The draft prohibits PCR discontinuities within a single group, requiring discontinuity indicators to be set in adaptation fields if PCR changes between groups. The 33-bit PCR base field wraps every ~26.5 hours of continuous stream time, a normal event for long-running live streams that receivers must handle as a timeline continuation. Subscribers joining a live track should start at a group with a random access point, and wait for a complete PSI cycle if m2tsRandomAccess is not set. Relays do not need to parse TS syntax, and can forward or cache objects using MOQT metadata; they should retain the first object of each group if random access is enabled to support new subscribers.

This draft lowers the barrier to adopting MOQT for media companies with existing TS-based infrastructure. Contribution workflows, which send live feeds from remote locations to studios, can use QUIC's low latency and congestion control without repackaging TS feeds. OTT providers can add MOQT as a low-latency delivery option alongside HLS and DASH, reusing their existing TS packaging pipelines. The draft also preserves support for SCTE-35 splice signaling and transport stream scrambling, so existing ad insertion and content protection workflows remain compatible.

The draft is informational, expires on November 7, 2026, and is open for discussion on the MOQ working group mailing list. The source code and issue tracker are available on GitHub, and the latest revision of the draft is hosted at https://mondain.github.io/msfts/draft-gregoire-moq-msfts.html. As MOQT and MSF progress toward RFC status, this m2ts packaging extension will fill a critical gap for legacy and existing media workflows.