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modify wave decoder to handle ima adpcm files

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adpcm
Dimitri Diakopoulos 10 years ago
parent 4b82d31b50
commit f3e03876a0
2 changed files with 62 additions and 29 deletions
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2
include/libnyquist/WavDecoder.h
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@ -35,9 +35,11 @@ enum WaveFormatCode
{
FORMAT_UNKNOWN = 0x0, // Unknown Wave Format
FORMAT_PCM = 0x1, // PCM Format
FORMAT_ADPCM = 0x2, // Microsoft ADPCM Format
FORMAT_IEEE = 0x3, // IEEE float/double
FORMAT_ALAW = 0x6, // 8-bit ITU-T G.711 A-law
FORMAT_MULAW = 0x7, // 8-bit ITU-T G.711 µ-law
FORMAT_IMA_ADPCM = 0x11, // IMA ADPCM Format
FORMAT_EXT = 0xFFFE // Set via subformat
};

73
src/WavDecoder.cpp
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@ -25,6 +25,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "WavDecoder.h"
#include "RiffUtils.h"
#include "IMA4Util.h"
using namespace nqr;
@ -84,7 +85,7 @@ int WavDecoder::LoadFromBuffer(AudioData * data, const std::vector<uint8_t> & me
if (WaveChunkInfo.offset == 0) throw std::runtime_error("couldn't find fmt chunk");
assert(WaveChunkInfo.size == 16 || WaveChunkInfo.size == 18 || WaveChunkInfo.size == 40);
assert(WaveChunkInfo.size == 16 || WaveChunkInfo.size == 18 || WaveChunkInfo.size == 20 || WaveChunkInfo.size == 40);
WaveChunkHeader wavHeader = {};
memcpy(&wavHeader, memory.data() + WaveChunkInfo.offset, sizeof(WaveChunkHeader));
@ -98,18 +99,33 @@ int WavDecoder::LoadFromBuffer(AudioData * data, const std::vector<uint8_t> & me
data->sampleRate = wavHeader.sample_rate;
data->frameSize = wavHeader.frame_size;
//std::cout << wavHeader << std::endl;
auto bit_depth = wavHeader.bit_depth;
switch (bit_depth)
{
case 4: data->sourceFormat = PCMFormat::PCM_16; break; // for IMA ADPCM
case 8: data->sourceFormat = PCMFormat::PCM_U8; break;
case 16: data->sourceFormat = PCMFormat::PCM_16; break;
case 24: data->sourceFormat = PCMFormat::PCM_24; break;
case 32: data->sourceFormat = (wavHeader.format == WaveFormatCode::FORMAT_IEEE) ? PCMFormat::PCM_FLT : PCMFormat::PCM_32; break;
case 64: data->sourceFormat = (wavHeader.format == WaveFormatCode::FORMAT_IEEE) ? PCMFormat::PCM_DBL : PCMFormat::PCM_64; break;
}
std::cout << wavHeader << std::endl;
bool scanForFact = false;
bool grabExtensibleData = false;
bool adpcmEncoded = false;
if (wavHeader.format == WaveFormatCode::FORMAT_PCM)
{
//std::cout << "[format id] pcm" << std::endl;
}
else if (wavHeader.format == WaveFormatCode::FORMAT_IEEE)
{
//std::cout << "[format id] ieee" << std::endl;
scanForFact = true;
}
else if (wavHeader.format == WaveFormatCode::FORMAT_IMA_ADPCM)
{
adpcmEncoded = true;
scanForFact = true;
}
else if (wavHeader.format == WaveFormatCode::FORMAT_EXT)
@ -128,16 +144,13 @@ int WavDecoder::LoadFromBuffer(AudioData * data, const std::vector<uint8_t> & me
// Read Additional Chunks //
////////////////////////////
FactChunk factChunk;
if (scanForFact)
{
auto FactChunkInfo = ScanForChunk(memory, GenerateChunkCode('f', 'a', 'c', 't'));
FactChunk factChunk = {};
if (FactChunkInfo.size)
{
memcpy(&factChunk, memory.data() + FactChunkInfo.offset, sizeof(FactChunk));
}
}
if (grabExtensibleData)
{
@ -172,23 +185,41 @@ int WavDecoder::LoadFromBuffer(AudioData * data, const std::vector<uint8_t> & me
DataChunkInfo.offset += 2 * sizeof(uint32_t); // ignore the header and size fields
data->lengthSeconds = ((float) DataChunkInfo.size / (float) wavHeader.sample_rate) / wavHeader.frame_size;
auto bit_depth = wavHeader.bit_depth;
size_t totalSamples = (DataChunkInfo.size / wavHeader.frame_size) * wavHeader.channel_count;
data->samples.resize(totalSamples);
switch (bit_depth)
if (adpcmEncoded)
{
case 8: data->sourceFormat = PCMFormat::PCM_U8; break;
case 16: data->sourceFormat = PCMFormat::PCM_16; break;
case 24: data->sourceFormat = PCMFormat::PCM_24; break;
case 32: data->sourceFormat = (wavHeader.format == WaveFormatCode::FORMAT_IEEE) ? PCMFormat::PCM_FLT : PCMFormat::PCM_32; break;
case 64: data->sourceFormat = (wavHeader.format == WaveFormatCode::FORMAT_IEEE) ? PCMFormat::PCM_DBL : PCMFormat::PCM_64; break;
ADPCMState s;
s.nBlockAlign = wavHeader.frame_size;
s.firstDataBlockByte = 0;
s.dataSize = DataChunkInfo.size;
s.currentByte = 0;
s.currentDatablock = const_cast<uint8_t*>(memory.data() + DataChunkInfo.offset);
// An encoded sample is 4 bits that expands to 16
size_t totalSamples = factChunk.sample_length * 4;
std::vector<int16_t> adpcm_pcm16(totalSamples, 0);
uint32_t frameOffset = 0;
unsigned numFrames = DataChunkInfo.size / s.nBlockAlign;
for (int i = 0; i < numFrames; ++i)
{
decode_ima_adpcm(s, adpcm_pcm16.data() + frameOffset, wavHeader.channel_count);
s.currentDatablock += s.nBlockAlign;
frameOffset += (wavHeader.channel_count * s.nBlockAlign);
}
data->lengthSeconds = ((float) totalSamples / (float) wavHeader.sample_rate) / wavHeader.channel_count;
data->samples.resize(totalSamples);
ConvertToFloat32(data->samples.data(), adpcm_pcm16.data(), totalSamples, data->sourceFormat);
}
else
{
data->lengthSeconds = ((float) DataChunkInfo.size / (float) wavHeader.sample_rate) / wavHeader.frame_size;
size_t totalSamples = (DataChunkInfo.size / wavHeader.frame_size) * wavHeader.channel_count;
data->samples.resize(totalSamples);
ConvertToFloat32(data->samples.data(), memory.data() + DataChunkInfo.offset, totalSamples, data->sourceFormat);
}
return IOError::NoError;
}

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