使用delphi读取.wav文件
我现在尝试使用delphi读取.wav文件。以下是我的代码:使用delphi读取.wav文件,delphi,matlab,delphi-7,wav,Delphi,Matlab,Delphi 7,Wav,我现在尝试使用delphi读取.wav文件。以下是我的代码: type TWaveHeader = packed record Marker_RIFF: array [0..3] of char; ChunkSize: cardinal; Marker_WAVE: array [0..3] of char; Marker_fmt: array [0..3] of char; SubChunkSize: cardinal; FormatTag
type
TWaveHeader = packed record
Marker_RIFF: array [0..3] of char;
ChunkSize: cardinal;
Marker_WAVE: array [0..3] of char;
Marker_fmt: array [0..3] of char;
SubChunkSize: cardinal;
FormatTag: word;
NumChannels: word;
SampleRate: longint;
BytesPerSecond: longint;
BytesPerSample: word;
BitsPerSample: word;
Marker_data: array [0..3] of char;
DataBytes: longint;
end;
TChannel = record
Data : array of double;
end;
一些私人的装饰
private
wavehdr:TWaveHeader;
wavedata:array[0..3]of TChannel;
numsamples:integer;
功能
FillChar(wavehdr, sizeof(wavehdr), 0);
Stream.Read(wavehdr, sizeof(wavehdr));
{ Log Header data }
with memo1.Lines do begin
Add('Filename : '+od.FileName);
Add('Header size : '+inttostr(sizeof(wavehdr)));
tmpstr := wavehdr.Marker_RIFF;
Add('RIFF ID : '+tmpstr+'');
Add('Chunk size : '+inttostr(wavehdr.ChunkSize));
tmpstr := wavehdr.Marker_WAVE;
Add('WAVE ID : '+tmpstr+'');
tmpstr := wavehdr.Marker_fmt;
Add('''fmt '' ID : '+tmpstr+''' ');
Add('SubChunk size : '+inttostr(wavehdr.SubChunkSize));
Add('Format : '+inttostr(wavehdr.FormatTag));
Add('Num Channels : '+inttostr(wavehdr.NumChannels));
Add('Sample rate : '+inttostr(wavehdr.SampleRate));
Add('Bytes per second : '+inttostr(wavehdr.BytesPerSecond));
Add('Bits per sample : '+inttostr(wavehdr.BitsPerSample));
Add('Block Align : '+inttostr((wavehdr.NumChannels*wavehdr.BitsPerSample)div 8));
end;
numsamples := (file.size div (wavehdr.NumChannels*wavehdr.BitsPerSample)div 8) div wavehdr.BytesPerSample;
case wavehdr.NumChannels of
1:begin
SetLength(wavedata[0].Data, numsamples);
Stream.Read(wavedata[0].Data[0], numsamples);
end;
2:begin
SetLength(wavedata[0].Data, numsamples);
SetLength(wavedata[1].Data, numsamples);
for i := 0 to high(wavedata[0].Data) do begin
Stream.Read(wavedata[0].Data[i], 2);
Stream.Read(wavedata[1].Data[i], 2);
end;
end;
end;
以上代码提供了与MATLAB完全相同的.wav头信息和细节,即:
文件名:E:\dephi\classic3.wav
RIFF-ID:RIFF
区块大小:18312354
WAVE-ID:WAVE
'fmt'ID:fmt'
子块大小:16
格式:1 PCM
频道数:2个立体声
抽样率:44100
每秒字节数:176400
每个样本位:16
块对齐:4
除了我根据wavedata-44的wavedata/blockalign的大小计算的总样本数据外,44是wav的标题。它不准确,有时会差5,1,10。我只使用了5个样本进行了测试。下面是一个示例:
classic1.wav matlab:3420288,delphimy计算:13681352/4-44=3420294
classic2.wav matlab:2912256,delphimy计算:11649204/4-44=2912257
而且matlab和delphi的样本数据值也不同
classic1.wav
MATLAB:前10个值leftchannel和rightchannel
-3.05175781250000e-05[]6.103515650000E-05
-6.103515650000E-05[]6.103515650000E-05
-6.103515650000E-05[]3.05175781250000e-05
0[]-3.05175781250000e-05
6.103515650000E-05[]-6.103515650000E-05
6.103515650000E-05[]-6.103515650000E-05
3.05175781250000e-05[]-3.0517578125000E-05
6.103515650000E-05[]-6.103515650000E-05
3.05175781250000e-05[]0
-3.05175781250000e-05[]6.103515650000E-05
DELPHI:前10个值leftchannel和rightchannel
9.9015690830442E-320[]1.00265682167023E-319
9.9015690830442E-320[]9.77113627780233E-320
3.26083326255223E-322[]0
1.39677298735779E-319[]1.3708839451571E-319
1.459321698129E-319[]1.33373021094845E-319
1.23175506164681E-319[]1.206903559661E-319
1.2823967934554E-319[]1.40932225476216E-319
1.37068632125737E-319[]1.33382902407761E-319
1.33373021094845E-319[]1.2568535964555555E-319
1.40907522193924E-319[]1.33358199125469E-319
我的问题是:
在查找wav文件的总样本时,如何正确执行?
matlab和delphi读取wav文件数据块的方式是否相同
不同的方式?或者我的密码是错的?
有没有一种方法可以像MATLAB那样获得相同的值?
编辑:我遵循mBo建议并将其更改为mBo建议
Data : array of SmallInt;
numsamples := wavehdr.DataBytes div (wavehdr.NumChannels * wavehdr.BitsPerSample div 8);
Stream.Read(wavedata[0].Data[i], SizeOf(SmallInt));
口译部分我不确定,但我把它改成了
floattostr(wavedata[0].Data[i]/32768.0)
floattostr(wavedata[1].Data[i]/32768.0)
我得到的结果是:
0.611602783203125 [] 0.61932373046875
0.611602783203125 [] 0.603546142578125
0.0023193359375 [] 0
0.862762451171875 [] 0.846771240234375
0.901397705078125 [] 0.823822021484375
0.760833740234375 [] 0.7454833984375
0.7921142578125 [] 0.870513916015625
0.799774169921875 [] 0.761016845703125
0.8238525390625 [] 0.782623291015625
0.354766845703125 [] 0.76123046875
每个示例的Wav文件位:16包含有符号的16位整数数据SmallInt类型,但您可以在浮点8字节双数组中读取数据 你可以申报
Data : array of SmallInt;
算计
numsamples := wavehdr.DataBytes div (wavehdr.NumChannels * wavehdr.BitsPerSample div 8);
把它们读作
Stream.Read(wavedata[0].Data[0], numsamples * SizeOf(SmallInt))
or multichannel case:
Stream.Read(wavedata[0].Data[i], SizeOf(SmallInt));
然后将数据值解释为浮点数据[i]/32768.0
请注意,matlab值3.0517578125000E-05=1/32768.0是每个样本16位信号的最小数量:16包含有符号16位整数数据SmallInt类型,但您在浮点8字节双数组中读取数据 你可以申报
Data : array of SmallInt;
算计
numsamples := wavehdr.DataBytes div (wavehdr.NumChannels * wavehdr.BitsPerSample div 8);
把它们读作
Stream.Read(wavedata[0].Data[0], numsamples * SizeOf(SmallInt))
or multichannel case:
Stream.Read(wavedata[0].Data[i], SizeOf(SmallInt));
然后将数据值解释为浮点数据[i]/32768.0
请注意,matlab值3.0517578125000E-05=1/32768.0是16位信号的最小量在解释数据值之前,我一直遵循您的建议,我使用类似floattostrwavedata[0]。数据[i]/32768.0,但仍然得到了与matlabwew不同的结果。我的问题是,经过几次调整后,现在工作正常。非常感谢。在解释数据值之前,我一直遵循您的建议。我使用floattostrwavedata[0]。data[i]/32768.0,但仍然得到了与matlabwew不同的结果。我的问题是,经过几次调整后,现在工作正常。非常感谢你