public static void WriteSingleChunkHeader(WavSingleChunkHeader header, Stream wavStream)
{
BinaryEndianWriter w = new BinaryEndianWriter(wavStream);
w.Write(Encoding.Default.GetBytes(header.FileId));
w.Write(header.FileLength);
w.Write(Encoding.Default.GetBytes(header.RiffType));
w.Write(Encoding.Default.GetBytes(header.ChunkHeaderId));
w.Write(header.ChunkHeaderLength);
w.Write(header.FormatTag);
w.Write(header.Channels);
w.Write(header.SamplesPerSec);
w.Write(header.AvgBytesPerSec);
w.Write(header.BlockAlign);
w.Write(header.BitsPerSample);
w.Write(header.ExtraBytes);
w.Write(Encoding.Default.GetBytes(header.ChunkId));
w.Write(header.ChunkLength);
}
public static void CreatePreview(int offset, int length, int fade, float volume, bool volumeApplied, string dstFilename, params AudioFile[] srcFilenames)
{
if (srcFilenames == null || srcFilenames.Length == 0 || (srcFilenames.Length == 1 && (srcFilenames[0] == null || srcFilenames[0].Name.Length == 0)))
return;
FileHelper.Delete(dstFilename);
WavSingleChunkHeader[] whi = new WavSingleChunkHeader[srcFilenames.Length];
BinaryEndianReader[] br = new BinaryEndianReader[srcFilenames.Length];
float[] vols = new float[srcFilenames.Length];
int outWav = 0; //use this input wav as the format for the output wav
int maxLen = 0;
for (int c = 0; c < srcFilenames.Length; c++)
{
br[c] = new BinaryEndianReader(File.OpenRead(srcFilenames[c].Name));
whi[c] = ParseWavSingleChunkHeader(br[c].BaseStream);
if (!volumeApplied)
vols[c] = srcFilenames[c].Volume / 100F; //get percentage
else
vols[c] = 1; //100%
//move to the correct point in each wav
uint wOffset = (uint)(whi[c].AvgBytesPerSec * ((float)offset / 1000));
wOffset -= wOffset % whi[c].BlockAlign;
br[c].BaseStream.Seek((long)wOffset, SeekOrigin.Current);
if (whi[c].AudioLength > maxLen)
maxLen = whi[c].AudioLength;
if (whi[c].Channels == 2)
outWav = c;
}
WavSingleChunkHeader who = new WavSingleChunkHeader();
if (length == 0)
length = maxLen;
uint wLength = (uint)(whi[outWav].AvgBytesPerSec * ((float)length / 1000));
wLength -= wLength % whi[outWav].BlockAlign;
who.FileId = "RIFF";
who.FileLength = (uint)(br[outWav].BaseStream.Length - whi[outWav].FileLength) + wLength;
who.RiffType = "WAVE";
who.ChunkHeaderId = "fmt ";
who.ChunkHeaderLength = whi[outWav].ChunkHeaderLength;
who.FormatTag = whi[outWav].FormatTag;
who.Channels = whi[outWav].Channels;
who.SamplesPerSec = whi[outWav].SamplesPerSec;
who.AvgBytesPerSec = whi[outWav].AvgBytesPerSec;
who.BlockAlign = whi[outWav].BlockAlign;
who.BitsPerSample = whi[outWav].BitsPerSample;
who.ExtraBytes = whi[outWav].ExtraBytes;
who.ChunkId = "data";
who.ChunkLength = wLength;
using (FileStream fso = File.OpenWrite(dstFilename))
{
WriteSingleChunkHeader(who, fso);
int loops = (int)((who.AvgBytesPerSec / who.BlockAlign) * ((float)length / 1000));
int fadeLen = (int)((who.AvgBytesPerSec / who.BlockAlign) * ((float)fade / 1000));
Double maxVol = (volume / (float)srcFilenames.Length); //reduce volume Audio in game
maxVol *= 1F + ((srcFilenames.Length - 1) * 0.33F); //add an extra third per file to cater for volume loss
Double vol = 0; //initial volume
if (fade == 0)
vol = maxVol;
int b32;
BinaryEndianWriter bw = new BinaryEndianWriter(fso);
Double step = (double)(maxVol - 0) / fadeLen; //fade in
if (Double.IsInfinity(step))
step = 0;
int allLeft = 0;
int allRight = 0;
long[] streamPos = new long[br.Length]; //fast way to track pos in stream
for (int c = 0; c < br.Length; c++)
streamPos[c] = br[c].BaseStream.Position;
long[] streamLen = new long[br.Length]; //fast way to get length of stream
for (int c = 0; c < br.Length; c++)
streamLen[c] = br[c].BaseStream.Length;
for (int i = 0; i != loops; i++)
{
if (i == fadeLen)
step = 0; //use max volume
if (i == loops - fadeLen) //fade out
step = (double)(0 - maxVol) / fadeLen;
allLeft = 0;
allRight = 0;
for (int c = 0; c < br.Length; c++) //each input stream
{
BinaryEndianReader b = br[c];
WavSingleChunkHeader w = whi[c];
//Left channel
b32 = 0;
if (streamPos[c] + 2 < streamLen[c])
{
b32 = (int)(b.ReadInt16(EndianType.Little) * vols[c]);
streamPos[c] += 2;
}
allLeft += (int)(b32 * vol);
allLeft = (short)Math.Max((int)short.MinValue, Math.Min((int)short.MaxValue, allLeft));
if (who.Channels > 1)
{
if (w.Channels > 1)
{
//Right channel
b32 = 0;
if (streamPos[c] + 2 < streamLen[c])
{
b32 = (int)(b.ReadInt16(EndianType.Little) * vols[c]);
streamPos[c] += 2;
}
}
allRight += (int)(b32 * vol);
allRight = (short)Math.Max((int)short.MinValue, Math.Min((int)short.MaxValue, allRight));
}
}
bw.Write((short)allLeft);
if (who.Channels > 1)
bw.Write((short)allRight);
vol += step;
}
foreach (BinaryEndianReader b in br)
b.Close();
fso.Flush();
}
}
public static void CreateSilentWav(int length, string dstFilename, bool stereo, int samplesPerSec)
{
FileHelper.Delete(dstFilename);
ushort bits = 16;
ushort channels = (ushort)(stereo ? 2 : 1);
ushort blockAlign = (ushort)(channels * 2);
WavSingleChunkHeader who = new WavSingleChunkHeader();
uint wLength = (uint)((float)(blockAlign * samplesPerSec) * (float)(length / 1000F));
wLength -= wLength % blockAlign;
who.FileId = "RIFF";
who.FileLength = (uint)(wLength + 46) - 8;
who.RiffType = "WAVE";
who.ChunkHeaderId = "fmt ";
who.ChunkHeaderLength = 18;
who.FormatTag = 1; //raw wav
who.Channels = channels;
who.SamplesPerSec = (uint)samplesPerSec;
who.AvgBytesPerSec = (uint)(blockAlign * samplesPerSec);
who.BlockAlign = blockAlign;
who.BitsPerSample = bits;
who.ExtraBytes = new byte[2];
who.ChunkId = "data";
who.ChunkLength = wLength;
using (FileStream fso = File.OpenWrite(dstFilename))
{
WriteSingleChunkHeader(who, fso);
byte[] buffer = new byte[who.AvgBytesPerSec];
for (int i = 0; i < buffer.Length; i++)
buffer[i] = 0;
long written = 0;
while (written + buffer.Length < wLength)
{
fso.Write(buffer, 0, buffer.Length);
written += buffer.Length;
}
if (written != wLength)
fso.Write(buffer, 0, (int)(wLength - written));
fso.Flush();
}
}
public static WavSingleChunkHeader ParseWavSingleChunkHeader(Stream wavStream)
{
WavSingleChunkHeader w = new WavSingleChunkHeader();
byte[] b;
BinaryEndianReader r = new BinaryEndianReader(wavStream);
b = r.ReadBytes(4);
w.FileId = Encoding.Default.GetString(b);
w.FileLength = r.ReadUInt32(EndianType.Little);
b = r.ReadBytes(4);
w.RiffType = Encoding.Default.GetString(b);
b = r.ReadBytes(4);
w.ChunkHeaderId = Encoding.Default.GetString(b);
w.ChunkHeaderLength = r.ReadUInt32(EndianType.Little);
long p = wavStream.Position;
w.FormatTag = r.ReadUInt16(EndianType.Little);
w.Channels = r.ReadUInt16(EndianType.Little);
w.SamplesPerSec = r.ReadUInt32(EndianType.Little);
w.AvgBytesPerSec = r.ReadUInt32(EndianType.Little);
w.BlockAlign = r.ReadUInt16(EndianType.Little);
w.BitsPerSample = r.ReadUInt16(EndianType.Little);
if (wavStream.Position - p != w.ChunkHeaderLength)
w.ExtraBytes = r.ReadBytes((int)(w.ChunkHeaderLength - (wavStream.Position - p)));
b = r.ReadBytes(4);
w.ChunkId = Encoding.Default.GetString(b);
w.ChunkLength = r.ReadUInt32(EndianType.Little);
w.DataOffset = (int)wavStream.Position;
return w;
}
public static void CreateSilentWav(int length, string dstFilename, params string[] srcFilenames)
{
if (srcFilenames == null || (srcFilenames.Length == 1 && srcFilenames[0].Length == 0))
return;
FileHelper.Delete(dstFilename);
WavSingleChunkHeader[] whi = new WavSingleChunkHeader[srcFilenames.Length];
BinaryEndianReader[] br = new BinaryEndianReader[srcFilenames.Length];
int outWav = 0; //use this input wav as the format for the output wav
for (int c = 0; c < srcFilenames.Length; c++)
{
br[c] = new BinaryEndianReader(File.OpenRead(srcFilenames[c]));
whi[c] = ParseWavSingleChunkHeader(br[c].BaseStream);
if (whi[c].Channels == 2)
outWav = c;
}
WavSingleChunkHeader who = new WavSingleChunkHeader();
uint wLength = (uint)((float)whi[outWav].AvgBytesPerSec * (float)(length / 1000F));
wLength -= wLength % whi[outWav].BlockAlign;
who.FileId = "RIFF";
who.FileLength = (uint)(whi[outWav].DataOffset + wLength) - 8;
who.RiffType = "WAVE";
who.ChunkHeaderId = "fmt ";
who.ChunkHeaderLength = whi[outWav].ChunkHeaderLength;
who.FormatTag = whi[outWav].FormatTag;
who.Channels = whi[outWav].Channels;
who.SamplesPerSec = whi[outWav].SamplesPerSec;
who.AvgBytesPerSec = whi[outWav].AvgBytesPerSec;
who.BlockAlign = whi[outWav].BlockAlign;
who.BitsPerSample = whi[outWav].BitsPerSample;
who.ExtraBytes = whi[outWav].ExtraBytes;
who.ChunkId = "data";
who.ChunkLength = wLength;
foreach (BinaryEndianReader b in br)
b.Close();
using (FileStream fso = File.OpenWrite(dstFilename))
{
WriteSingleChunkHeader(who, fso);
byte[] buffer = new byte[who.AvgBytesPerSec];
for (int i = 0; i < buffer.Length; i++)
buffer[i] = 0;
long written = 0;
while (written + buffer.Length < wLength)
{
fso.Write(buffer, 0, buffer.Length);
written += buffer.Length;
}
if (written != wLength)
fso.Write(buffer, 0, (int)(wLength - written));
fso.Flush();
}
}