VS1053B Datasheet, PDF (60/79 Pages) List of Unclassifed Manufacturers – Ogg Vorbis/MP3/AAC/WMA/MIDI AUDIO CODEC

VLSI
Solution ^y
VS1053b preliminary
VS1053B
9. OPERATION
9.11.3 AAC
Parameter
config1
sceFoundMask
cpeFoundMask
lfeFoundMask
playSelect
dynCompress
dynBoost
sbrAndPsStatus
Address
0x1e03(7:4)
0x1e2a
0x1e2b
0x1e2c
0x1e2d
0x1e2e
0x1e2f
0x1e30
Usage
SBR and PS select
Single channel elements found
Channel pair elements found
Low frequency elements found
Play element selection
Compress coefficient for DRC, -8192=1.0
Boost coefficient for DRC, 8192=1.0
SBR and PS available flags
playSelect determines which element to decode if a stream has multiple elements. The value is
set to 0 each time AAC decoding starts, which causes the first element that appears in the stream to be
selected for decoding. Other values are: 0x01 - select first single channel element (SCE), 0x02 - select
first channel pair element (CPE), 0x03 - select first low frequency element (LFE), S ∗ 16 + 5 - select
SCE number S, P ∗ 16 + 6 - select CPE number P, L ∗ 16 + 7 - select LFE number L. When automatic
selection has been performed, playSelect reflects the selected element.
sceFoundMask, cpeFoundMask, and lfeFoundMask indicate which elements have been found
in an AAC stream since the variables have last been cleared. The values can be used to present an element
selection menu with only the available elements.
dynCompress and dynBoost change the behavior of the dynamic range control (DRC) that is present
in some AAC streams. These are also initialized when AAC decoding starts.
sbrAndPsStatus indicates spectral band replication (SBR) and parametric stereo (PS) status.
Bit Usage
0 SBR present
1 upsampling active
2 PS present
3 PS active
Bits 7 to 4 in config1 can be used to control the SBR and PS decoding. Bits 5 and 4 select SBR mode
and bits 7 and 6 select PS mode. These configuration bits are useful if your AAC license does not cover
SBR and/or PS.
config1(5:4)
’00’
’01’
’10’
’11’
Usage
normal mode, upsample <24 kHz AAC files
do not automatically upsample <24 kHz AAC files, but
enable upsampling if SBR is encountered
never upsample
disable SBR (also disables PS)
Version 0.5, 2007-12-03
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