L64105 LSI Logic Corporation, L64105 Datasheet - Page 198

• Manufacturer Part Number: L64105
• Description: Mpeg-2 Audio/video Decoder
• Manufacturer: LSI Logic Corporation

6-2
as a set of elementary streams that share the same system clock
reference and therefore can be decoded synchronously. In MPEG-1,
there are only two levels of hierarchy in the system syntax. In MPEG-2,
there are four levels of hierarchy in the system syntax. The following table
shows the system streams for MPEG-1 and MPEG-2 system syntax.
Table 6.1
MPEG-2 introduced the Packetized Elementary Stream (PES) to allow
multiple streams and multiple programs to be combined in a single
stream. An MPEG-2 system may transmit either a program stream that
contains PES packets for a single program, or a transport stream that
contains PES packets for multiple, possibly unrelated, programs. An
MPEG-2 system decoder therefore must be able to accept PES data
from a transport stream or from a program stream. The crucial difference
between these two is that a program stream contains variable-length
PES packets, but a transport multiplexer reforms input PES packets into
fixed, 188-byte packets (184 payload bytes and 4 header bytes). While
program streams are generally used in DVD applications, transport
streams are usually fed into set top boxes.
The Channel Interface, shown in
System Synchronizer, Video Layer Synchronizer, Preparser, Channel
Write FIFO, and a Buffer Controller.
Channel Interface
MPEG-1 Streams
System Stream
Elementary Stream Elementary Stream
Levels of Hierarchy in MPEG-1 and MPEG-2 System
Syntax
MPEG-2 Streams
Transport Stream
Program Stream
Packetized Elementary Stream (PES)
Figure
6.1, includes an Input FIFO,