MPEG-2 Transport Stream

MPEG-2 Transport Stream
Name	MPEG-2 Transport Stream
Standard	ISO/IEC 13818-1
Developed by	Moving Picture Experts Group
First published	1993
Applications	Digital television, DVB, ATSC, ISDB, IPTV, satellite

MPEG-2 Transport Stream The MPEG-2 Transport Stream is a digital container format standardized as ISO/IEC 13818-1 that carries audio, video, and data for broadcast and streaming in environments such as DVB and ATSC. It provides packetized multiplexing, program metadata, and synchronization for lossy channels used by Eutelsat, SES, Intelsat, DirecTV, and Dish Network. Widely adopted by broadcasters like the BBC, NHK, Rai, ZDF, and companies such as Sony, Panasonic, Samsung Electronics, it underpins services delivered over infrastructures managed by Cisco Systems, Juniper Networks, Ericsson, Huawei Technologies, and Nokia.

Overview

The format originates from work by the Moving Picture Experts Group within ISO and IEC to support systems including Digital Video Broadcasting and Advanced Television Systems Committee frameworks. It complements standards such as MPEG-1, MPEG-2 Part 2, MPEG-2 Part 3, MPEG-2 Part 4, and codecs like H.264, H.265, and VC-1 for compatibility in workflows involving manufacturers including LG Electronics, Philips, Hitachi, and service providers like Sky UK and Canal+. Implementations interoperate with middleware from NDS Group, OpenTV, Rovi Corporation, and with conditional access systems from Irdeto, Conax, Nagravision.

History and Standardization

Standardized in 1995 after collaborative research by organizations including ISO, IEC, ITU, and industry stakeholders such as Thomson SA, Matsushita Electric Industrial Co., RCA, and Bell Labs. Influences trace through projects sponsored by European Broadcasting Union and testing in trials with broadcasters like CBC, TV Asahi, Televisa, and satellite operators Astra (satellite) and Galileo (satellite). The evolution parallels regulatory activity by bodies like the Federal Communications Commission and Ofcom and later harmonization with ISDB initiatives in Japan led by NHK and ARIB.

Transport Stream Structure and Components

A transport stream consists of 188-byte packets used to carry elementary streams like MPEG-1 Audio Layer III, Dolby Digital, AC-3, AAC, and video coded with MPEG-2 Video or H.264/MPEG-4 AVC. It defines packet identifiers (PIDs), program maps, conditional access sections, and null packets to maintain constant bitrates for networks operated by SES Astra, Telesat, and Eutelsat. Components interact with service information in systems deployed by Deutsche Telekom, Orange S.A., Telefonica, and content providers like Netflix, HBO, Disney, Warner Bros., and Universal Pictures.

Packetization and Synchronization

Packetization employs fixed-size 188-byte packets with 4-byte headers including sync byte, transport_error_indicator, payload_unit_start_indicator, and continuity_counter; synchronization aligns elementary streams via PCR, PTS, and DTS timestamps compatible with decoders built by Samsung Electronics, Sony Corporation, Toshiba, Sharp Corporation, and chipset vendors Broadcom, NXP Semiconductors, Intel, AMD, Qualcomm. Use of PCR enables synchronization across modulation schemes such as QPSK, 8PSK, 16QAM, and 64QAM used by transmitters from Anritsu, Rohde & Schwarz, and Tektronix.

Multiplexing, PSI and Metadata

Multiplexers create program streams and program-specific information (PSI) tables—PAT, PMT, CAT—and metadata constructs that integrate with electronic program guides provided by Gracenote, TiVo, and Scripps Networks Interactive. PSI interworks with service information standards like DVB-SI and metadata frameworks for conditional access overseen by CableLabs, ETSI, and broadcaster consortia including SMPTE and AES. Transport streams may carry DVB subtitles, teletext, AC-3 metadata, and SCTE signaling used by cable operators such as Comcast, Charter Communications, and Virgin Media.

Error Protection and Robustness

Designed for error-prone channels, the transport stream supports Reed–Solomon forward error correction in satellite links managed by Intelsat and interleaving with convolutional coding referenced in standards by CCITT groups and adopted in DVB-S and DVB-T systems. Robustness features include null packet stuffing, scrambling, and adaptation_field mechanisms, enabling operation over terrestrial networks maintained by Nokia Networks and under disaster-response scenarios coordinated with agencies like FEMA and ITU-R.

Applications and Implementations

Employed in digital terrestrial television rollouts by Freeview (UK), Freeview Australia, Freeview NZ, cable deployments by RCA Cable Systems and satellite uplinks by Eutelsat, as well as IPTV platforms from Verizon FiOS, AT&T U-verse, and streaming point-to-point services by Akamai Technologies. Hardware implementations appear in set-top boxes from Humax, Pace plc, Arris International, and professional encoders from Harmonic Inc., Grass Valley, Telestream, and TVU Networks. Software tools for analysis and generation include projects maintained by FFmpeg, GStreamer, VLC media player, and open-source efforts at DVB Project and VideoLAN.

Category:Digital television standards