iOS Development--wave Audio file parsing

WAV files are also divided into several categories, the corresponding non-data information stored in the file's head, the following simple mention, and then at the end of the focus on the 44-byte type, the general use is this.

1, 8KHz sampling, 16-bit quantization of linear PCM voice signal wave file Header Format table (total 44 bytes)

Offset address byte Number data type content file header defined as

00h   4   char      "RIFF"   char riff_id[4]= "RIFF"
&nb Sp  04H   4   long   file length -8     long int size0= Length-8
&nbs P  08H   8   char  "wavefmt "      char wave_fmt[8]
10h&　　nbsp  4   long       Filter bytes (typically 10H)   long size1=0x10
14h   2    　 int      Encoding (01 00h) int fmttag=0x01
16H   2   int channels (1 mono, 2 for two channels) int channel=1  or 2
18H   4   long   Sample rate   Long int samplesper SEC
1ch   4   long     transfer rate         Long int bytepers EC = Sample Frequency * Number of channels * Quantization/8

20H 2 int block Alignment (sampled bytes) int blockalign= Channels * Quantization number/8
22H 2 int quantization ( sampling accuracy ) int bitpersamples=8 or 16
24H 4 Char "data" char data_id[4]= "data"
28H 4 Long data part length long int size2= Wenchang-44
2CH to end char sample data

2, 8KHz sampling, 8-bit A-law quantization of PCM voice signal wave file Header format table (total 58 bytes)

Offset address byte Number data type content file header defined as
00H 4 Char "RIFF" char riff_id[4]= "RIFF"
04H 4 long int file total length -8-long int size0=-8
08H 8 char "wavefmt" Char wave_fmt[8]
10H 4 long int 12000000H (ALAW) long int size1=0x12
14H 2 int, 00H int fmttag=0x06
16H 2 int channel number int channel=1 or 2
18H 4 long int sample rate long int samplespersec
1CH 4 long int plays bytes per second long int bytepersec
20H 2 int Sampling byte-count int blockalign=0x01
22H 4 Long int quantization number long int bitpersamples=8
26H 4 Char "fact" char wave_fact= "fact"
2AH 8 char 0400000000530700H fixed char temp
32H 4 Char "data" char wave_data= "data"
36H 4 long int sampled data bytes Lont int size2= Wenchang-58

3, 8KHz sampling, 8-bit U-law quantization of PCM voice signal wave file Header format table (total 58 bytes)

Offset address byte Number data type content file header defined as
00H 4 Char "RIFF" char riff_id[4]= "RIFF"
04H 4 long int file total length -8-long int size0=-8
08H 8 char "wavefmt" Char wave_fmt[8]
10H 4 long int 12000000H (ULAW) long int size1=0x12
14H 2 int fmttag=0x07 00H int
16H 2 int channel number int channel=1 or 2
18H 4 long int sample rate long int samplespersec
1CH 4 long int plays bytes per second long int bytepersec
20H 2 int Sampling byte-count int blockalign=0x01
22H 4 Long int quantization number long int bitpersamples=8
26H 4 Char "fact" char wave_fact= "fact"
2AH 8 char 0400000000530700H fixed char temp
32H 4 Char "data" char wave_data= "data"
36H 4 long int sampled data bytes Lont int size2= Wenchang-58

4, ADPCM voice encoded wave file Header format table (total 90 bytes)

Offset address byte Number data type content file header defined as
00H 4 Char "RIFF" char riff_id[4]= "RIFF"
04H 4 long int file total length -8-long int size0=-8
08H 8 char "wavefmt" Char wave_fmt[8]
10H 4 long int 32000000H (ADPCM) long int size1=0x32
14H 2 int 00H int fmttag=0x02
16H 2 int channel number int channel=1 or 2
18H 4 long int sample rate long int samplespersec
1CH 4 long int plays bytes per second long int bytepersec
20H 2 int sampling one time in bytes int blockalign= number of channels * Quantization/8
22H 2 int quantization number int bitpersamples=4
24H Char fixed byte char temp1
46H 4 Char "fact" char wave_fact= "fact"
4AH 8 char 0400000004930600H fixed char temp2
52H 4 Char "data" char wave_data= "data"
56H 4 long int sampled data bytes Lont int size2= Wenchang-90
5AH to end sampled data

5, GSM voice encoded wave file Header format table (total 60 bytes)

Offset address byte Number data type content file header defined as
00H 4 Char "RIFF" char riff_id[4]= "RIFF"
04H 4 long int file total length -8-long int size0=-8
08H 8 char "wavefmt" Char wave_fmt[8]
10H 4 long int 14000000H (GSM) long int size1=0x14
14H 2 int 00H int fmttag=0x31
16H 2 int channel number int channel=1 or 2
18H 4 long int sample rate long int samplespersec
1CH 4 long int plays bytes per second long int bytepersec
20H 8 char 4100000002004001H fixed char Temp1
28H 8 char 6661637404000000H fixed char temp2
30H 4 char E2 00H fixed char Temp3
34H 4 Char "data" char wave_data= "data"
38H 4 long int sampled data bytes Lont int size2= Wenchang-60
3CH to end sampled data

6, SBC Voice encoded wave file Header format table (total 58 bytes)

Offset address byte Number data type content file header defined as
00H 4 Char "RIFF" char riff_id[4]= "RIFF"
04H 4 long int file total length -8-long int size0=-8
08H 8 char "wavefmt" Char wave_fmt[8]
10H 4 long int 12000000H (SBC) long int size1=0x12
14H 2 int 00H int fmttag=0x71
16H 2 int channel number int channel=1 or 2
18H 4 long int sample rate long int samplespersec
1CH 4 long int plays bytes per second long int bytepersec
20H 2 int Sampling byte-count int blockalign=0x25
22H 4 Long int quantization number long int bitpersamples=16
26H 4 Char "fact" char wave_fact= "fact"
2AH 8 char 0400000076280400H fixed char temp
32H 4 Char "data" char wave_data= "data"
36H 4 long int sampled data bytes Lont int size2= Wenchang-59

7, CELP voice encoded wave file Header format table (total 58 bytes)

Offset address byte Number data type content file header defined as
00H 4 Char "RIFF" char riff_id[4]= "RIFF"
04H 4 long int file total length -8-long int size0=-8
08H 8 char "wavefmt" Char wave_fmt[8]
10H 4 long int 12000000H (CELP) long int size1=0x12
14H 2 int 00H int fmttag=0x70
16H 2 int channel number int channel=1 or 2
18H 4 long int sample rate long int samplespersec
1CH 4 long int plays bytes per second long int bytepersec
20H 2 int Sampling byte-count int blockalign=0x0c
22H 4 Long int quantization number long int bitpersamples=16
26H 4 Char "fact" char wave_fact= "fact"
2AH 8 char 0400000060520700H fixed char temp
32H 4 Char "data" char wave_data= "data"
36H 4 long int sampled data bytes Lont int size2= Wenchang-58

iOS Development--wave Audio file parsing