CT8022 Datasheet, PDF (185/194 Pages) List of Unclassifed Manufacturers – VOIP/VON G.723.1, G279AB TRUESPEECH CO-PROCESSOR

Version: 1.18
PRELIMINARY/CONFIDENTIAL
TrueSpeech® Co-Processor
C Wave File Format (.wav)
WAVE file format is actually a sub-format of RIFF (Resource Interchange File Format) and is as follows:
Example for 8/16 bit linear data (the byte offsets given are for illustration only; the byte offsets in a wave file are not
absolute):
Byte Offset
0000H
0004H
0008H
Number of Bytes
4
4
4
Contents
“RIFF” = 52 49 46 46 (hex)
filesize -8 (the size of the waveform chunk)
“WAVE” = 57 41 56 45 (hex)
000CH
4
0010H
4
0014H
2
0016H
2
0018H
4
001CH
4
0020H
2
0022H
2
“fmt “ = 66 6D 74 20 (hex)
format chunk size (16 for linear data)
wFormatTag = 1 (WAVE_FORMAT_PCM)
nChannels (number of channels 1:mono 2:stereo)
nSamplesPerSec (e.g. 8000)
nAvgBytesPerSec (.e.g. 8000, 16000)
nBlockAlign (block size in bytes 8-bit mono:1, 16 bit stereo:4)
wBitsPerSample (e.g. 8 or 16)
0024H
4
0028H
4
002CH
“data” = 64 61 74 61 (hex)
waveform data size (bytes)
start of actual waveform data
Example for TrueSpeech data (the byte offsets given are for illustration only; the byte offsets in a wave file are not
absolute):
Byte Offset
0000H
0004H
0008H
Number of Bytes
4
4
4
Contents
“RIFF” = 52 49 46 46 (hex)
filesize -8 (the size of the waveform chunk)
“WAVE” = 57 41 56 45 (hex)
000CH
4
0010H
4
0014H
2
0016H
2
0018H
4
001CH
4
0020H
2
0022H
2
0024H
2
0026H
2
0028H
2
002AH
28
“fmt “ = 66 6D 74 20 (hex)
format chunk size = 32H
wFormatTag = 22H (TrueSpeech tag value)
nChannels = 1
nSamplesPerSec = 8000
nAvgBytesPerSec = 1067 (used for buffer size estimation)
nBlockAlign = 20H
wBitsPerSample = 1
cbSize = 20H (size of extension area following)
wRevision = 1 (For TrueSpeech 8.5)
nSamplesPerBlock = 240
abReserved[28] (reserved area)
0042H
4
0046H
4
004AH
4
004EH
4
0052H
4
0056H
“fact” = 66 61 63 74
fact chunk size = 4
time length of data in sample units (e.g. 8000 = 1 sec)
“data” = 64 61 74 61 (hex)
waveform data size (bytes)
start of actual waveform data
CT8022A11AQC FW Revision 0118
DSP GROUP, INC., 3120 SCOTT BOULEVARD
185
SANTA CLARA, CA 95054 PH: 408 986 – 4300 FAX: 408 986 – 4490
All specifications are subject to change without prior notice.