JEITA CP-3451
- 83 -
Address Offset
Code
Meaning
(Hex)
(Hex)
+00
52
+01
49
+02
46
+03
46
"RIFF"
(ckID)
+04
ckSize
(4 Bytes)
+08
57
+09
41
+0A
56
+0B
45
"WAVE"
(formType)
+0C
fmt-ck
(26 Bytes)
m-Law format information (size is
26 bytes fixed)
+26
fact-ck
(12 Bytes)
Samples per channel-unit block
(m-Law format)
+32
data-ck
PCM format audio data
Figure 41 Basic Structure of m-Law Format
The specific values of the information stored in fmt-ck and fact-ck in the case of the m-Law format are given in Table
26.
Table 26 fmt-ck and fact-ck Information in m-Law Format
m-Law (ITU-T G.711) Format
Members
Code
ckSize(fmt-ck)
00000012.H (18 bytes, WAVEFORMATEX only)
wFormatTag
0007.H (m-Law format)
nChannels
The values of each mode are as follows.
0001.H (monaural) or 0002.H (stereo)
nSamplesPerSec
00001F40.H (8.0kHz)
nAvgBytesPerSec
The values of each mode are as follows.
00001F40.H (8.0kHz, 8-bit monaural)
00003E80.H (8.0kHz, 8-bit stereo)
Definition: nSamplesPerSec * nBlockAlign
nBlockAlign
The values of each mode are as follows.
0001.H (8bit monaural)
0002.H (8bit stereo)
Definition: nChannels * wBitsPerSample/8
wBitsPerSample
0008.H (8bit)
cbSize
0000.H (extByte[cbSize] does not exist)
extByte[cbSize]
Not used
dwSampleLength
It is recommended that the actual number of samples that can be
played be recorded here.
Definition: (ckSize_of_data-ck) / nBlockAlign