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Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal

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9.1.3.1 Elementary stream (ES):

Elementary stream or ES is the output of an audio or video encoder. Elementary streams

contain only one kind of data. The data can be audio or video. The sizes of these data are fixed

to 8 bits for the video when it is broadcasted (10 when it is stored in the studio) and 16 bits for

the audio either at broadcast or at the studio use. There are some cases that it can be referred

as “elementary data, audio or video, stream or bitstream”. The format of the elementary

stream depends on the codec or the data carried in the stream, but they often carry a common

header when they are packetized into a packetized elementary stream.

Image 9.1.3.1.1: ES structure (from the presentation of Walter Fischer in Belgium 2008).

9.1.3.2 Packetized elementary stream (PES):

All elementary streams in MPEG are first packetized in variable-length packets called PES

packets. The packets, which primarily have a length of 64 kbytes, begin with a PES header of 6

bytes minimum length. The first 3 bytes of this header represent the “start code prefix”. The

byte following the start code is the “stream ID”. After that there are two “packet length” bytes

and after these 6 bytes of PES header, an “optional PES header” is transmitted which is an

optional extension of the PES header and is adapted to the requirements of the elementary

stream currently being transmitted. At the end of the optional PES header there may also be

stuffing bytes. Following the complete PES header, the actual payload of the elementary stream

is transmitted which can usually be up to 64 kbytes long or even longer in special cases, plus the

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