1.2.5. Initialization Segment

[...]

Container specific examples of initialization segments:
[...]

MPEG-2 Transport Stream
MPEG-2 TS packets carrying PSI

1.2.6. Media Segment

[...]
Container specific examples of media segments:

[...]
MPEG-2 TS packets carrying media data and (optionally) PSI.

[...]

6.3 MPEG-2 Transport Stream Byte Streams
This section is non-normative.

This section defines segment formats for implementations that choose to support MPEG-2 Transport Stream ISO/IEC 13818-1:2012 (MPEG-2 TS).

6.3.1. General
MPEG-2 TS media and initialization segments used in this specification shall conform to the MPEG-2 TS Adaptive Profile (ISO/IEC 13818-1:2012 Amd. 2).
The following rules shall apply to all MPEG-2 TS media segments:
1. Segments shall contain complete MPEG-2 TS packets. 
2. Segments shall contain exactly one program.
3. Each TS packet shall have transport_error_indicator set to '0'.

6.3.2. Initialization Segments

An MPEG-2 TS initialization segment shall contain a single PAT and a single PMT. Each one of these tables should be contained in a single transport stream packet.

6.3.3. Media Segments

The following rules shall apply to all MPEG-2 TS media segments:
1. Media Segments shall contain only complete PES packets. 
2. Each PES packet shall be comprised of one or more complete access units in each packet. 
3. Each PES packet shall have a PTS timestamp.
4. PCR shall be present in the Segment prior to the first byte of a TS packet payload containing media data.
5. The presentation duration of each media component within the Media Segment should be should be as close to equal as practical.

6.3.4. Establishing the Presentation Start Timestamp

The earliest presentation timestamp of any sample of the first media segment appended establishes the starting timestamp for the presentation timeline, thus time 0:00:00 on presentation timeline corresponds to the smallest PTS value of the first media segment. 
All media segments appended after this first segment are expected to have PTS values greater than or equal to this timestamp.  Note that PTS is a 33-bit value, consequently PTS rollovers should be accounted for.

6.3.5. Random Access Points

A random access point as defined in this specification corresponds to Elementary Stream Random Access Point as defined in ISO/IEC 13818-1:2012.