BizHawk/DiscoHawk/Wave/WaveFile.cs

98 lines
4.1 KiB
C#

/* Wave File Library
* A simple library to write a wave file
*
* Garrett Hoofman
* 10/21/08
* http://www.visionsofafar.com
* */
/* Wave File Format
Reference : http://ccrma.stanford.edu/CCRMA/Courses/422/projects/WaveFormat/
The canonical WAVE format starts with the RIFF header:
0 4 ChunkID Contains the letters "RIFF" in ASCII form
(0x52494646 big-endian form).
4 4 ChunkSize 36 + SubChunk2Size, or more precisely:
4 + (8 + SubChunk1Size) + (8 + SubChunk2Size)
This is the size of the rest of the chunk
following this number. This is the size of the
entire file in bytes minus 8 bytes for the
two fields not included in this count:
ChunkID and ChunkSize.
8 4 Format Contains the letters "WAVE"
(0x57415645 big-endian form).
The "WAVE" format consists of two subchunks: "fmt " and "data":
The "fmt " subchunk describes the sound data's format:
12 4 Subchunk1ID Contains the letters "fmt "
(0x666d7420 big-endian form).
16 4 Subchunk1Size 16 for PCM. This is the size of the
rest of the Subchunk which follows this number.
20 2 AudioFormat PCM = 1 (i.e. Linear quantization)
Values other than 1 indicate some
form of compression.
22 2 NumChannels Mono = 1, Stereo = 2, etc.
24 4 SampleRate 8000, 44100, etc.
28 4 ByteRate == SampleRate * NumChannels * BitsPerSample/8
32 2 BlockAlign == NumChannels * BitsPerSample/8
The number of bytes for one sample including
all channels. I wonder what happens when
this number isn't an integer?
34 2 BitsPerSample 8 bits = 8, 16 bits = 16, etc.
2 ExtraParamSize if PCM, then doesn't exist
X ExtraParams space for extra parameters
The "data" subchunk contains the size of the data and the actual sound:
36 4 Subchunk2ID Contains the letters "data"
(0x64617461 big-endian form).
40 4 Subchunk2Size == NumSamples * NumChannels * BitsPerSample/8
This is the number of bytes in the data.
You can also think of this as the size
of the read of the subchunk following this
number.
44 * Data The actual sound data.
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.IO;
namespace WaveLibrary
{
public class WaveFile
{
WaveHeader header;
WavefmtSubChunk fmt;
WavedataSubChunk data;
public WaveFile(int channels, int bitsPerSample, int sampleRate)
{
header = new WaveHeader();
fmt = new WavefmtSubChunk(channels, bitsPerSample, sampleRate);
}
public void SetData(byte[] SoundData, int numSamples)
{
data = new WavedataSubChunk(numSamples, fmt.NumChannels, fmt.BitsPerSample, SoundData);
}
public void WriteFile(string file)
{
FileStream fs = File.Create(file);
//Set the total file chunk size
//Has to be set here because we might not know what the actual Data size was until now
header.SetChunkSize(fmt.Size, data.Size);
header.WriteHeader(fs);
fmt.Writefmt(fs);
data.WriteData(fs);
fs.Close();
fs.Dispose();
}
public int NumChannels { get { return fmt.NumChannels; }}
public int BitsPerSample { get { return fmt.BitsPerSample; }}
}
}