
L64005 MPEG-2 Audio/Video Decoder Technical Manual
1-11
Final Rev F
Copyright 1996 by LSI Logic Corporation. All rights reserved.
Audio Frame Header
Data in the audio frame header set the parameters that describe the
format and mode of the audio data.
Audio Frame Cyclic Redundancy Code (CRC)
This eld contains a 16-bit checksum, which can be used to detect
errors in the audio frame header.
Audio Data
The L64005 uses the audio data to reconstruct the sampled audio
data. Its format is beyond the scope of this document. The data
structures for Layer I dual channel/stereo, intensity stereo, and for
the more complex Layer II audio data elds are described in Sections
2.4.1.5 and 2.4.1.6 of the ISO CD 11172-3.
Ancillary Data
The nal eld in an audio frame contains user-dened data (ancillary
data).
1.2.2
Audio Decoding
Audio decoding is the reverse of audio encoding and is intended to
reconstruct the compressed audio data. MPEG audio decoding involves:
identifying and removing a channel’s audio frames from the audio
packets in the System Stream
managing the temporary storage of frames
applying appropriate algorithms for decoding the audio frames
merging decoded audio frames back into continuous audio
limiting the effect of transmission errors
1.3
Standards
Compliance
The L64005 conforms to the following international standards:
MPEG-1. ISO/IEC 11172 (1993) Information Technology—Coding of
Moving Picture and Associated Audio for Digital Storage Media at up
to about 1.5 Mbit/s.
MPEG-2. ISO/IEC 13818 Generic Coding of Moving Pictures and
Associated Audio, International Standard.