I. Various WAV file header formats

Wav files are also divided into several types, and the corresponding non-data information is stored in the file header section. Below are various WAV file header formats.

Table 1 wave File Header Format for 8 KHz sampling and 16-bit quantization of linear PCM speech signals (44 bytes in total)
Offset address byte data type content file header is defined
00 H 4 char "riff" char riff_id [4] = "riff"
04 H 4 long int file total length-8 long int size0 = total length-8
08 h 8 char "wavefmt" char wave_fmt [8]
10 H 4 long int 10 00 00 00 H (PCM) Long int size1 = 0x10
14 H 2 int 01 00 h int fmttag = 0x01
16 H 2 int channel = 1 or 2
18 H 4 long int sampling rate long int samplespersec
1ch 4 long int playback bytes per second long int bytepersec
20 H 2 int sampling number of occupied segments at a time int blockalign = number of channels * quantization number/8
22 h 2 int quantization number int bitpersamples = 8 or 16
24 h 4 char "data" char data_id = "data"
28 H 4 long int sample data bytes long int size2 = length-44
2 CH to end char sampling data

 

 

Table 2 8 KHz sampling, 8-Bit A-Law Quantization of PCM voice signal wave File Header Format table (58 bytes in total)

Offset address byte data type content file header is defined
00 H 4 char "riff" char riff_id [4] = "riff"
04 H 4 long int file total length-8 long int size0 = total length-8
08 h 8 char "wavefmt" char wave_fmt [8]
10 H 4 long int 12000000 H (alaw) Long int size1 = 0x12
14 H 2 int 06 00 h int fmttag = 0x06
16 H 2 int channels int channel = 1 or 2
18 H 4 long int sampling rate long int samplespersec
1ch 4 long int playback bytes per second long int bytepersec
20 H 2 int sampling number of characters at a time int blockalign = 0x01
22 h 4 long int quantization number long int bitpersamples = 8
26 H 4 char "fact" char wave_fact = "fact"
2ah 8 char 0400000000530700h fixed char temp
32 H 4 char "data" char wave_data = "data"
36 H 4 long int sample data bytes lont int size2 = length-58

 

 

Table 3. 8 KHz sampling and 8-bit U-Law Quantization of PCM voice signal wave File Header Format table (58 bytes in total)

Offset address byte data type content file header is defined
00 H 4 char "riff" char riff_id [4] = "riff"
04 H 4 long int file total length-8 long int size0 = total length-8
08 h 8 char "wavefmt" char wave_fmt [8]
10 H 4 long int 12000000 H (ulaw) Long int size1 = 0x12
14 H 2 int 07 00 h int fmttag = 0x07
16 H 2 int channels int channel = 1 or 2
18 H 4 long int sampling rate long int samplespersec
1ch 4 long int playback bytes per second long int bytepersec
20 H 2 int sampling number of characters at a time int blockalign = 0x01
22 h 4 long int quantization number long int bitpersamples = 8
26 H 4 char "fact" char wave_fact = "fact"
2ah 8 char 0400000000530700h fixed char temp
32 H 4 char "data" char wave_data = "data"
36 H 4 long int sample data bytes lont int size2 = length-58

 

 

Table 4 Wave File Header Format table after ADPCM Speech Encoding (90 bytes in total)

 

Offset address byte data type content file header is defined
00 H 4 char "riff" char riff_id [4] = "riff"
04 H 4 long int file total length-8 long int size0 = total length-8
08 h 8 char "wavefmt" char wave_fmt [8]
10 H 4 long int 32000000 H (ADPCM) Long int size1 = 0x32
14 H 2 int 02 00 h int fmttag = 0x02
16 H 2 int channels int channel = 1 or 2
18 H 4 long int sampling rate long int samplespersec
1ch 4 long int playback bytes per second long int bytepersec
20 H 2 int sampling number of occupied segments at a time int blockalign = number of channels * quantization number/8
22 h 2 int quantization number int bitpersamples = 4
24 h 34 char fixed byte char temp1
46 H 4 char "fact" char wave_fact = "fact"
4ah 8 char 0400000004930600h fixed char temp2
52 H 4 char "data" char wave_data = "data"
56 H 4 long int sampled data bytes lont int size2 = length-90
5ah-end sampling data

 

 

Table 5 formats of wave file headers after GSM Speech Encoding (60 bytes in total)

Offset address byte data type content file header is defined
00 H 4 char "riff" char riff_id [4] = "riff"
04 H 4 long int file total length-8 long int size0 = total length-8
08 h 8 char "wavefmt" char wave_fmt [8]
10 H 4 long int 14000000 H (GSM) Long int size1 = 0x14
14 H 2 int 31 00 h int fmttag = 0x31
16 H 2 int channels int channel = 1 or 2
18 H 4 long int sampling rate long int samplespersec
1ch 4 long int playback bytes per second long int bytepersec
20 h 8 char 400000002004001h set char temp1
28 h 8 char 66616374040020.h fixed char temp2
30 H 4 char 40 E2 05 00h fixed char temp3
34 H 4 char "data" char wave_data = "data"
38 H 4 long int sample data bytes lont int size2 = length-60
3 ch to end-to-end sampling data

 

 

Table 6 SBC audio-encoded wave File Header Format table (58 bytes in total)

Offset address byte data type content file header is defined
00 H 4 char "riff" char riff_id [4] = "riff"
04 H 4 long int file total length-8 long int size0 = total length-8
08 h 8 char "wavefmt" char wave_fmt [8]
10 H 4 long int 12000000 H (SBC) Long int size1 = 0x12
14 H 2 int 71 00 h int fmttag = 0x71
16 H 2 int channels int channel = 1 or 2
18 H 4 long int sampling rate long int samplespersec
1ch 4 long int playback bytes per second long int bytepersec
20 H 2 int sampling number of characters at a time int blockalign = 0x25
22 h 4 long int quantization number long int bitpersamples = 16
26 H 4 char "fact" char wave_fact = "fact"
2ah 8 char 040011676280400h set char temp
32 H 4 char "data" char wave_data = "data"
36 H 4 long int sampled data bytes lont int size2 = length-59

 

 

Table 7 wave File Header Format table after CELP Speech Encoding (58 bytes in total)

Offset address byte data type content file header is defined
00 H 4 char "riff" char riff_id [4] = "riff"
04 H 4 long int file total length-8 long int size0 = total length-8
08 h 8 char "wavefmt" char wave_fmt [8]
10 H 4 long int 12000000 H (CELP) Long int size1 = 0x12
14 H 2 int 70 00 h int fmttag = 0x70
16 H 2 int channels int channel = 1 or 2
18 H 4 long int sampling rate long int samplespersec
1ch 4 long int playback bytes per second long int bytepersec
20 H 2 int sampling number of characters at a time int blockalign = 0x0c
22 h 4 long int quantization number long int bitpersamples = 16
26 H 4 char "fact" char wave_fact = "fact"
2ah 8 char 040011660520700h fixed char temp
32 H 4 char "data" char wave_data = "data"
36 H 4 long int sample data bytes lont int size2 = length-58

 

Waveformatex

Typedef struct {word wformattag; Word nchannels; DWORD nsamplespersec; DWORD navgbytespersec; Word nblockalign; Word wbitspersample; Word cbsize;} waveformatex;

The specific parameters are described as follows:
Wformattag: the format of waveform data, defined in mmreg. h file
Nchannels: number of channels for waveform data: single channel or stereo
Nsamplespersec: sampling rate. For PCM format waveform data, the sampling rate is 8.0 kHz, 11.025 kHz, 22.05 kHz, 44.1 kHz, etc.
Navgbytespersec: data rate. For PCM waveform data, the data rate equals to the sampling rate multiplied by the number of bytes per sample.
Nblockalign: number of bytes per sample
Wbitspersample: Sampling Accuracy. For PCM format waveform data, the sampling accuracy is 8 or 16
Cbsize: size of the data block with additional format information
Concept 2. Define the device header Structure
Wavehdr defines the device header pointing to the waveform data buffer.

Wavehdr

Typedef struct {lpstr lpdata; DWORD dwbufferlength; DWORD dwbytesrecorded; DWORD dwuser; DWORD dwflags; DWORD dwloops; struct wavehdr_tag * lpnext; DWORD reserved;} wavehdr;

Lpdata: the buffer address of the waveform data
Dwbufferlength: the length of the buffer address of the waveform data
Dwbytesrecorded: indicates the length of the input data when the device is used for recording.
Dwuser: User Data
Dwflags: the buffer attribute of the waveform data
Dwloops: the number of playback cycles. It is only used for playback control.
Both lpnext and reserved are reserved values.
Note: The above struct and the "hwavein" and "hwaveout" struct used in the program all exist in the system. You only need to assign values to them.