Program streams are created by combining one or more
packetized elementary streams (PES), which have a common time base, into a single stream. It is designed for reasonably reliable media such as disks, in contrast to
MPEG transport stream which is for data transmission in which loss of data is likely. Program streams have variable size records and minimal use of
start codes which would make over the air reception difficult, but has less overhead. Program stream coding layer allows only one
program of one or more elementary streams to be packaged into a single stream, in contrast to transport stream, which allows multiple programs. International Organization for Standardization authorized
SMPTE Registration Authority, LLC as the registration authority for MPEG-2 format identifiers. It publishes a list of compression formats which can be encapsulated in MPEG-2 transport stream and program stream. ==Coding details==