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[BUGFIX] Fix 32-bit (fixed-point) PCM WAVE loading #22

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Merged
merged 2 commits into from
Aug 16, 2025
Merged

[BUGFIX] Fix 32-bit (fixed-point) PCM WAVE loading #22

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575c72a
Fix 32-bit (fixed-point) PCM WAVE loading
sdatkinson Aug 16, 2025
76c2d48
Merge branch 'main' into 21-32bit
sdatkinson Aug 16, 2025
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21 changes: 18 additions & 3 deletions dsp/wav.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -307,7 +307,7 @@ dsp::wav::LoadReturnCode ReadDataChunk(std::ifstream& wavFile, WaveFileData& wfd
if (audioFormat == AUDIO_FORMAT_IEEE)
{
if (wfd.fmtChunk.bitsPerSample == 32)
dsp::wav::_LoadSamples32(wavFile, wfd.dataChunk.size, audio);
dsp::wav::_LoadSamples32FloatingPoint(wavFile, wfd.dataChunk.size, audio);
else
{
std::cerr << "Error: Unsupported bits per sample for IEEE files: " << wfd.fmtChunk.bitsPerSample << std::endl;
Expand All @@ -321,7 +321,7 @@ dsp::wav::LoadReturnCode ReadDataChunk(std::ifstream& wavFile, WaveFileData& wfd
else if (wfd.fmtChunk.bitsPerSample == 24)
dsp::wav::_LoadSamples24(wavFile, wfd.dataChunk.size, audio);
else if (wfd.fmtChunk.bitsPerSample == 32)
dsp::wav::_LoadSamples32(wavFile, wfd.dataChunk.size, audio);
dsp::wav::_LoadSamples32FixedPoint(wavFile, wfd.dataChunk.size, audio);
else
{
std::cerr << "Error: Unsupported bits per sample for PCM files: " << wfd.fmtChunk.bitsPerSample << std::endl;
Expand Down Expand Up @@ -456,10 +456,25 @@ int dsp::wav::_ReadSigned24BitInt(std::ifstream& stream)
return value;
}

void dsp::wav::_LoadSamples32(std::ifstream& wavFile, const int chunkSize, std::vector<float>& samples)
void dsp::wav::_LoadSamples32FloatingPoint(std::ifstream& wavFile, const int chunkSize, std::vector<float>& samples)
{
// NOTE: 32-bit is float.
samples.resize(chunkSize / 4); // 32 bits (4 bytes) per sample
// Read the samples from the file into the array
wavFile.read(reinterpret_cast<char*>(samples.data()), chunkSize);
}

void dsp::wav::_LoadSamples32FixedPoint(std::ifstream& wavFile, const int chunkSize, std::vector<float>& samples)
{
// Allocate an array to hold the samples
std::vector<int> tmp(chunkSize / 4); // 32 bits (4 bytes) per sample

// Read the samples from the file into the array
wavFile.read(reinterpret_cast<char*>(tmp.data()), chunkSize);

// Copy into the return array
const float scale = 1.0 / ((double)(1 << 31)); // 2^31 for 32-bit fixed point
samples.resize(tmp.size());
for (auto i = 0; i < samples.size(); i++)
samples[i] = scale * ((float)tmp[i]);
}
4 changes: 3 additions & 1 deletion dsp/wav.h
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Original file line number Diff line number Diff line change
Expand Up @@ -45,7 +45,9 @@ void _LoadSamples16(std::ifstream& wavFile, const int chunkSize, std::vector<flo
// Load samples, 24-bit
void _LoadSamples24(std::ifstream& wavFile, const int chunkSize, std::vector<float>& samples);
// Load samples, 32-bit
void _LoadSamples32(std::ifstream& wavFile, const int chunkSize, std::vector<float>& samples);
void _LoadSamples32FloatingPoint(std::ifstream& wavFile, const int chunkSize, std::vector<float>& samples);
// Load samples, 32-bit fixed point
void _LoadSamples32FixedPoint(std::ifstream& wavFile, const int chunkSize, std::vector<float>& samples);

// Read in a 24-bit sample and convert it to an int
int _ReadSigned24BitInt(std::ifstream& stream);
Expand Down