The MPEG-2 Transport Stream (
MPEG2-TS, M2TS or
TS) is a standard container format specified in MPEG-2 Part 1, Systems (ISO/IEC standard 13818-1).
MPEG2-TSencapsulates digital audio and video, offering error correction and synchronization features. Introduced in 1995, it has been extensively used for transmission and storage in
broadcastsystems such as DVB, ATSC and
Recent years have seen the rapid adoption and rise of Adaptive Bitrate (
ABR) streaming over HTTP, as employed in Over the Top (
OTT), Video on Demand (VoD), Pay TV and other internet based media delivery services.
MPEG2-TScontinues to play an important role in
ABRstreaming through its adoption as the encapsulation format for segments in
ABRstreaming standards such as
Apple HTTP Live Streaming(
Along with the adoption of
ABRstreaming, there has been a significant focus on video compression efficiencies to provide users with a better experience over constrained and varying network conditions. Many streaming services have adopted advanced video compression standards such as
VP9, often at significant costs due to increased computational complexity and costs associated with deployment of a new codec.
At the same time,
overheadscan constitute up to 15% of the total bandwidth, especially for lower bit rate video representations. These
overheadshave often been overlooked in efforts to reduce bandwidth. Most of the packaging overhead comes from the following elements of
MPEG2-TS, used to encapsulate
PESHeaders Compressed video and audio Elementary Streams (ES) of one or more frames are packetized to produce Packetized Elementary Streams (
StuffingIn order to provide better error concealment,
PMT/SDT and other PSI/SI tables Program Specific Information (PSI)/Service Information (SI) tables consist of normative data which are necessary for de-multiplexing of transport streams and successful regeneration of programs.
PCRand Timing information Another important constituent of
PES) packets before being encapsulated in a Transport Stream (
PESpacket contains a
PESHeader of 14-19 bytes.
TSpacket size to a fixed 188 bytes. Each
TSpacket begins with a 4 byte Header and zero or more
stuffingbytes to maintain the fixed 188 byte length.
MPEG2-TSis the timing information required to synchronize servers and clients. This includes information such as Program Clock Reference (
PCR), Presentation Time Stamp (
PTS) and Decoding Time Stamp (
The structure of the
TSheaders are illustrated in the diagram below.
Each of these elements are required to transmit essential information and cannot be eliminated altogether. Optimizing the
overheadsrequires a comprehensive understanding of the
MPEG2-TSstandard, deployed players, networks and service parameters.
Advanced packager and segmenter implementations in Ittiam’s