L64105 LSI Logic Corporation, L64105 Datasheet - Page 343

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

Figure 10.2 MPEG Audio Bitstream Syntax
Sync word (12 bits)
ID (1 bit)
Layer (2 bits)
Protection (1 bit)
bitrate_index (4 bits)
sampling_freq (2 bits)
Padding (1 bit)
private_bit (1 bit)
Mode (2 bits)
mode_ext (2 bits)
Copyright (1 bit)
Original (1 bit)
Emphasis (1 bit)
(4 bytes)
Header
Frame
MPEG Audio Decoder
(2 bytes)
CRC
1152 Samples (Layer II)
384 Samples (Layer I),
Layer I Data
Layer II Data
Frame
Variable Length
Allocate 4 bits
(32 subbands)
(lookup table)
per subband
Audio Data
Allocate
Scale factors, 6 bits
Scale factors, 6 bits
per used subband
Frame
sclf_index, 2 bits
used subband
Aux
(up to 32 sb)
1 to 3 per
Frame
Samples of 2
Samples of 2
to 15 bits in
to 15 bits
Length
10-11