Author: Kniebusch Horst

I have a very big wave file and I want to split it into two separately files. But, 
this two files have to stand alone. You should can  play and edit them like another 
wave files.

Answer:

If you know how wave files work, this is very easy.
First you need the complete file header of the old wave file:


1   type
2     TWaveHeader = record
3       ident1: array[0..3] of Char;       // Must be "RIFF"
4       len: DWORD;                        // remaining length after this header
5       ident2: array[0..3] of Char;       // Must be "WAVE"
6       ident3: array[0..3] of Char;       // Must be "fmt "
7       reserv: DWORD;                     // Reserved Size
8       wFormatTag: Word;                  // format type
9       nChannels: Word;                   // number of channels (i.e. mono, stereo, 
10  etc.)
11      nSamplesPerSec: DWORD;             //sample rate
12      nAvgBytesPerSec: DWORD;            //for buffer estimation
13      nBlockAlign: Word;                 //block size of data
14      wBitsPerSample: Word;              //number of bits per sample of mono data
15      cbSize: Word;                      //the count in bytes of the size of
16      ident4: array[0..3] of Char;       //Must be "data"
17  end;
18  
19  
20  //You can load the file header with this function:
21  
22  
23  function GetWaveHeader(FileName: TFilename): TWaveHeader;
24  const
25    riff = 'RIFF';
26    wave = 'WAVE';
27  var
28    f: TFileStream;
29    w: TWaveHeader;
30  begin
31    if not FileExists(Filename) then
32      exit;
33  
34    try
35      f := TFileStream.create(Filename, fmOpenRead);
36      f.read(w, Sizeof(w));
37  
38      if w.ident1 <> riff then
39      begin
40        Showmessage('This is not a RIFF File');
41        exit;
42      end;
43  
44      if w.ident2 <> wave then
45      begin
46        Showmessage('This is not a valid wave file');
47        exit;
48      end;
49  
50    finally
51      f.free;
52    end;
53  
54    Result := w;
55  end;
56  
57  
58  //Now we have all for creating the code for spliting the wave file:
59  
60  
61  
62  function SplitWave(Source, Dest1, Dest2: TFileName; Pos: Integer): Boolean;
63  var
64    f1, f2, f3: TfileStream;
65    w: TWaveHeader;
66    p: Integer;
67  begin
68    Result:=False
69  
70    if not FileExists(Source) then
71      exit;
72  
73    try
74      w := GetWaveHeader(Source);
75  
76      p := Pos - Sizeof(TWaveHeader);
77  
78      f1 := TFileStream.create(Source, fmOpenRead);
79      f2 := TFileStream.create(Dest1, fmCreate);
80      f3 := TFileStream.create(Dest2, fmCreate);
81  
82      {++++++++++Create file 1 ++++++++++++++++}
83      w.len := p;
84      f2.write(w, Sizeof(w));
85      f1.position := Sizeof(w);
86      f2.CopyFrom(f1, p);
87      {++++++++++++++++++++++++++++++++++++++++}
88  
89      {+++++++++++Create file 2 +++++++++++++++}
90      w.len := f1.size - Pos;
91      f3.write(w, Sizeof(w));
92      f1.position := Pos;
93      f3.CopyFrom(f1, f1.size - pos);
94      {++++++++++++++++++++++++++++++++++++++++}
95    finally
96      f1.free;
97      f2.free;
98      f3.free;
99    end;
100 
101   Result:=True;
102 end;