USBB17AP77016-XXX-B11 NEC Electronics, USBB17AP77016-XXX-B11 Datasheet - Page 19

• Manufacturer Part Number: USBB17AP77016-XXX-B11
• Description: DSP middleware(WMA (Windows Media Audio)decoder)
• Manufacturer: NEC Electronics

2.3.3
[Classification]
[Function name]
[Summary of function] Creates PCM data from the results of decoding wmad_FileDecodeData.
[Format]
[Arguments]
[Return value]
[Function]
[Registers used]
[Hardware resources]
[Remark]
wmad_FileGetPCM function
WMA decode processing function
wmad_FileGetPCM
and stores PCM data totaling the number of requested PCM samples multiplied by the
number of channels in the specified buffer in the X memory. In the case of 2-channel data,
data is stored alternately in the order of L channel then R channel. For the argument
indicating the number of requested PCM samples, specify a value that is either the same
as or smaller than the PCM buffer size (but at least 1). If the return value indicating the
number of acquired PCM samples is smaller than the number of requested PCM samples,
it indicates that decoding of all the data stored in the static area has finished. To acquire
the next PCM data, re-execute the wmad_FileDecodeData function. Note that the size of
the user-defined output buffer can be reduced by reducing the number of requested PCM
samples.
R0, R1, R2, R3, R4, R5, R6, R7,
DP0, DP1, DP2, DP3, DP4, DP5,
DN0, DN2, DN5, DN7
The maximum number of cycles is the value when the number of acquired PCM samples
per channel is 2048.
call wmad_FileGetPCM
This function converts the decoding results stored in the static area into PCM-format data
R0L
R1L
R1
Maximum stack level
Maximum loop stack level
Maximum number of repetitions
Maximum number of cycles
Return Value
Argument
CHAPTER 2 LIBRARY SPECIFICATIONS
User’s Manual U15683EJ1V0UM
Start address of output buffer (X memory)
Number of requested PCM samples (per channel)
Number of acquired PCM samples (per channel)
Description
Description
2.1 × 10
4
1
0
5
19