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#include "stdafx.h"
#include "WavSound.h"
#include "Exception.h"
namespace sound {
struct RiffChunk {
char header[4];
nat size;
char format[4];
};
struct FmtChunk {
char chunkId[4];
nat size;
unsigned short audioFmt;
unsigned short numCh;
nat rate;
nat byteRate;
unsigned short blockAlign;
unsigned short bitsPerSample;
};
struct DataChunk {
char chunkId[4];
nat size;
};
template <class T>
void fill(IStream *from, T &out) {
GcPreArray<byte, sizeof(T)> data;
storm::Buffer b = from->fill(storm::emptyBuffer(data));
if (!b.full())
throw new (from) SoundOpenError(S("Not enough data."));
memcpy(&out, b.dataPtr(), sizeof(T));
}
WavSound::WavSound(IStream *src, Bool seekable) : src(src), seekable(seekable) {
RiffChunk riff;
fill(src, riff);
if (strncmp(riff.header, "RIFF", 4) != 0)
throw new (this) SoundOpenError(S("Invalid header."));
if (strncmp(riff.format, "WAVE", 4) != 0)
throw new (this) SoundOpenError(S("Unsupported wave format."));
FmtChunk fmt;
fill(src, fmt);
if (strncmp(fmt.chunkId, "fmt ", 4) != 0)
throw new (this) SoundOpenError(S("Invalid subchunk."));
if (fmt.size != 16)
throw new (this) SoundOpenError(S("Invalid chunk size."));
if (fmt.audioFmt != 1)
throw new (this) SoundOpenError(S("Compression in wave files is not supported."));
rate = fmt.rate;
ch = fmt.numCh;
sampleDepth = fmt.bitsPerSample;
sampleSize = fmt.blockAlign;
if (sampleDepth != 8 && sampleDepth != 16)
throw new (this) SoundOpenError(S("Unsupported bit depth."));
DataChunk data;
fill(src, data);
if (strncmp(data.chunkId, "data", 4) != 0)
throw new (this) SoundOpenError(S("Invalid data chunk."));
if (seekable)
dataStart = ((RIStream *)src)->tell();
dataLength = data.size / sampleSize;
}
void WavSound::close() {
if (src)
src->close();
src = null;
}
Word WavSound::tell() {
if (seekable)
return dataPos;
else
return 0;
}
Bool WavSound::seek(Word to) {
if (!seekable)
return false;
dataPos = max(dataLength, to);
RIStream *s = (RIStream *)src;
s->seek(dataStart + dataPos*sampleSize);
return true;
}
Word WavSound::length() {
if (seekable)
return dataLength;
else
return 0;
}
Nat WavSound::sampleFreq() const {
return rate;
}
Nat WavSound::channels() const {
return ch;
}
Buffer WavSound::read(Buffer to) {
Nat free = to.count() - to.filled();
Nat samples = free / ch;
dataPos = min(dataLength, dataPos + samples);
storm::Buffer src = this->src->fill(samples * sampleSize);
Nat out = to.filled();
switch (sampleDepth) {
case 8:
for (Nat i = 0; i < src.filled(); i++) {
to[out++] = (src[i]/128.0f) - 1.0f;
}
break;
case 16:
for (Nat i = 0; i < src.filled(); i += 2) {
short data = src[i];
data |= short(src[i+1]) << 8;
to[out++] = float(data)/float(0x8000);
}
break;
default:
out = to.count();
break;
}
to.filled(out);
return to;
}
Bool WavSound::more() {
return dataPos < dataLength;
}
WavSound *openWav(RIStream *src) {
return new (src) WavSound(src, true);
}
WavSound *openWavStream(IStream *src) {
return new (src) WavSound(src, false);
}
}
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