Datasheet

The meaning of the flags are shown in the follow-
ing tables:
MPEG IDs
IDex ID
0 0 MPEG 2.5
0 1 reserved
1 0 MPEG 2
1 1 MPEG 1
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.
bitrate index ID = 1 ID = 0
’0000’ free free
’0001’ 32 8
’0010’ 40 16
’0011’ 48 24
’0100’ 56 32
’0101’ 64 40
’0110’ 80 48
’0111’ 96 56
’1000’ 112 64
’1001’ 128 80
’1010’ 160 96
’1011’ 192 112
’1100’ 224 128
’1101’ 256 144
’1110’ 320 160
’1111’ forbidden forbidden
Sampling Frequency
indicates the sampling frequency of the encoded
audio signal (KHz) depending on the MPEG ID
Sampling
Frequency
MPEG1 MPEG2 MPEG2.5
’00’ 44.1 22.05 11.03
’01’ 48 24 12
’10’ 32 16 8
’11’ reserved reserved reserved
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 mode specified
’00’ stereo
’01’ joint stereo (intensity_stereo and/or ms_stereo)
’10’ dual_channel
’11’ single_channel (mono)
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.
emphasis emphasis specified
’00’ none
’01’ 50/15 microseconds
’10’ reserved
’11’ CCITT J,17
STA013 - STA013B - STA013T
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