Creative SB0350 Hardware Programming Guide - Page 134

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B-10 File Format For a 22 050Hz sampling rate stereo digitized sound, the Time Constant is calculated as follows: Time Constant = 65536 - (256 000 000 / (2 * 22 050)) = 59732 (0E95H) bPackMethod This is a 1-byte field which indicates the packing method used by the digitized sound data of this block. The meaning of the field is the same as the bPackMethod field in Block Type 1: bVoiceMode This is a 1-byte field which indicates mono or stereo digitized sound (0 for mono and 1 for stereo). After this block, the digitized sound attributes carried by the following Block Type 1 is ignored. Block Type 9 This is a digitized sound data block that supersedes Block Types 1 and 8. The Block Header is organized as follows: BYTE BYTE DWORD BYTE BYTE WORD BYTE bBlockID; nBlockLen[3]; dwSamplesPerSec; bBitsPerSample; bChannels; wFormat; reserved[4]; // == 9 // 3-byte block length // pad with zero The header is followed immediately by the digitized sound data. The four reserved bytes at the end are there for two reasons: 1. 2. Pad the header up to a length of 16 bytes (a convenient size for manipulation). Provide for future expansion. Here is a brief discussion of the various fields: bBlockID The Block Type identifier is 9.

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B-10
File Format
For a 22 050Hz sampling rate stereo digitized sound, the Time Constant
is calculated as follows:
Time Constant
= 65536 - (256 000 000 / (2 * 22 050))
= 59732 (0E95H)
bPackMethod
This is a 1-byte field which indicates the packing method used by the
digitized sound data of this block.
The meaning of the field is the same as
the
bPackMethod
field in Block Type 1:
bVoiceMode
This is a 1-byte field which indicates mono or stereo digitized sound (0
for mono and 1 for stereo).
After this block, the digitized sound attributes carried by the following Block Type 1 is
ignored.
Block Type 9
This is a digitized sound data block that supersedes Block Types 1 and 8.
The Block
Header is organized as follows:
BYTE
bBlockID;
// == 9
BYTE
nBlockLen[3];
// 3-byte block length
DWORD
dwSamplesPerSec;
BYTE
bBitsPerSample;
BYTE
bChannels;
WORD
wFormat;
BYTE
reserved[4];
// pad with zero
The header is followed immediately by the digitized sound data.
The four reserved bytes at the end are there for two reasons:
1.
Pad the header up to a length of 16 bytes (a convenient size for manipulation).
2.
Provide for future expansion.
Here is a brief discussion of the various fields:
bBlockID
The Block Type identifier is 9.