sta003t STMicroelectronics, sta003t Datasheet - Page 16

• Manufacturer Part Number: sta003t
• Description: Mpeg 2.5 Layer Iii Audio Decoder
• Manufacturer: STMicroelectronics

STA003T
The meaning of the flags are shown in the follow-
ing tables:
MPEG IDs
Layer
in Layer III these two flags must be set always to
"01".
Protection_bit
It equals "1" if no redundancy has been added
and "0" if redundancy has been added.
Bitrate_index
indicates the bitrate (Kbit/sec) depending on the
MPEG ID.
Sampling Frequency
indicates the sampling frequency of the encoded
audio signal (KHz) depending on the MPEG ID
16/32
Frequency
Sampling
bitrate index
’00’
’01’
’10’
’11’
’0000’
’0001’
’0010’
’0011’
’0100’
’0101’
’0110’
’0111’
’1000’
’1001’
’1010’
’1011’
’1100’
’1101’
’1110’
’1111’
IDex
0
0
1
1
not supported not supported not supported
reserved
MPEG1
48
32
not supported
not supported
not supported
not supported
not supported
forbidden
ID = 1
free
112
128
32
40
48
56
64
80
96
ID
0
1
0
1
reserved
MPEG2
24
16
MPEG 2.5
reserved
MPEG 2
MPEG 1
not supported
not supported
forbidden
ID = 0
MPEG2.5
free
reserved
112
128
16
24
32
40
48
56
64
80
96
8
12
8
Padding bit
if this bit equals ’1’, the frame contains an addi-
tional slot to adjust the mean bitrate to the sam-
pling frequency, otherwise this bit is set to ’0’.
Private bit
Bit for private use. This bit will not be used in the
future by ISO/IEC.
Mode
Indicates the mode according to the following ta-
ble. The joint stereo mode is intensity_stereo
and/or ms_stereo.
Mode extension
These bits are used in joint stereo mode. They in-
dicates which type of joint stereo coding method
is applied. The frequency ranges, over which the
intensity_stereo and ms_stereo modes are ap-
plied, are implicit in the algorithm.
Copyright
If this bit is equal to ’0’, there is no copyright on
the bitstream, ’1’ means copyright protected.
Original/Copy
This bit equals ’0’ if the bitstream is a copy, ’1’ if it
is original.
Emphasis
Indicates the type of de-emphasis that shall be
used.
mode
emphasis
’00’
’01’
’10’
’11’
’00’
’01’
’10’
’11’
stereo
joint stereo (intensity_stereo and/or ms_stereo)
dual_channel
single_channel (mono)
none
50/15 microseconds
reserved
CCITT J,17
mode specified
emphasis specified