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Diffstat (limited to 'src/adpcm/adpcm.cpp')
| -rw-r--r-- | src/adpcm/adpcm.cpp | 398 |
1 files changed, 398 insertions, 0 deletions
diff --git a/src/adpcm/adpcm.cpp b/src/adpcm/adpcm.cpp new file mode 100644 index 0000000..d05fca6 --- /dev/null +++ b/src/adpcm/adpcm.cpp @@ -0,0 +1,398 @@ +/*****************************************************************************/ +/* adpcm.cpp Copyright (c) Ladislav Zezula 2003 */ +/*---------------------------------------------------------------------------*/ +/* This module contains implementation of adpcm decompression method used by */ +/* Storm.dll to decompress WAVE files. Thanks to Tom Amigo for releasing */ +/* his sources. */ +/*---------------------------------------------------------------------------*/ +/* Date Ver Who Comment */ +/* -------- ---- --- ------- */ +/* 11.03.03 1.00 Lad Splitted from Pkware.cpp */ +/* 20.05.03 2.00 Lad Added compression */ +/* 19.11.03 2.01 Dan Big endian handling */ +/* 10.01.13 3.00 Lad Refactored, beautified, documented :-) */ +/*****************************************************************************/ + +#include "../StormPort.h" +#include "adpcm.h" + +//----------------------------------------------------------------------------- +// Tables necessary dor decompression + +static int NextStepTable[] = +{ + -1, 0, -1, 4, -1, 2, -1, 6, + -1, 1, -1, 5, -1, 3, -1, 7, + -1, 1, -1, 5, -1, 3, -1, 7, + -1, 2, -1, 4, -1, 6, -1, 8 +}; + +static int StepSizeTable[] = +{ + 7, 8, 9, 10, 11, 12, 13, 14, + 16, 17, 19, 21, 23, 25, 28, 31, + 34, 37, 41, 45, 50, 55, 60, 66, + 73, 80, 88, 97, 107, 118, 130, 143, + 157, 173, 190, 209, 230, 253, 279, 307, + 337, 371, 408, 449, 494, 544, 598, 658, + 724, 796, 876, 963, 1060, 1166, 1282, 1411, + 1552, 1707, 1878, 2066, 2272, 2499, 2749, 3024, + 3327, 3660, 4026, 4428, 4871, 5358, 5894, 6484, + 7132, 7845, 8630, 9493, 10442, 11487, 12635, 13899, + 15289, 16818, 18500, 20350, 22385, 24623, 27086, 29794, + 32767 +}; + +//----------------------------------------------------------------------------- +// Helper class for writing output ADPCM data + +class TADPCMStream +{ + public: + + TADPCMStream(void * pvBuffer, size_t cbBuffer) + { + pbBufferEnd = (unsigned char *)pvBuffer + cbBuffer; + pbBuffer = (unsigned char *)pvBuffer; + } + + bool ReadByteSample(unsigned char & ByteSample) + { + // Check if there is enough space in the buffer + if(pbBuffer >= pbBufferEnd) + return false; + + ByteSample = *pbBuffer++; + return true; + } + + bool WriteByteSample(unsigned char ByteSample) + { + // Check if there is enough space in the buffer + if(pbBuffer >= pbBufferEnd) + return false; + + *pbBuffer++ = ByteSample; + return true; + } + + bool ReadWordSample(short & OneSample) + { + // Check if we have enough space in the output buffer + if((pbBufferEnd - pbBuffer) < sizeof(short)) + return false; + + // Write the sample + OneSample = pbBuffer[0] + (((short)pbBuffer[1]) << 0x08); + pbBuffer += sizeof(short); + return true; + } + + bool WriteWordSample(short OneSample) + { + // Check if we have enough space in the output buffer + if((pbBufferEnd - pbBuffer) < sizeof(short)) + return false; + + // Write the sample + *pbBuffer++ = (unsigned char)(OneSample & 0xFF); + *pbBuffer++ = (unsigned char)(OneSample >> 0x08); + return true; + } + + int LengthProcessed(void * pvBuffer) + { + return pbBuffer - (unsigned char *)pvBuffer; + } + + unsigned char * pbBufferEnd; + unsigned char * pbBuffer; +}; + +//---------------------------------------------------------------------------- +// Local functions + +static inline short GetNextStepIndex(int StepIndex, unsigned int EncodedSample) +{ + // Get the next step index + StepIndex = StepIndex + NextStepTable[EncodedSample & 0x1F]; + + // Don't make the step index overflow + if(StepIndex < 0) + StepIndex = 0; + else if(StepIndex > 88) + StepIndex = 88; + + return (short)StepIndex; +} + +static inline int UpdatePredictedSample(int PredictedSample, int EncodedSample, int Difference) +{ + // Is the sign bit set? + if(EncodedSample & 0x40) + { + PredictedSample -= Difference; + if(PredictedSample <= -32768) + PredictedSample = -32768; + } + else + { + PredictedSample += Difference; + if(PredictedSample >= 32767) + PredictedSample = 32767; + } + + return PredictedSample; +} + +static inline int DecodeSample(int PredictedSample, int EncodedSample, int StepSize, int Difference) +{ + if(EncodedSample & 0x01) + Difference += (StepSize >> 0); + + if(EncodedSample & 0x02) + Difference += (StepSize >> 1); + + if(EncodedSample & 0x04) + Difference += (StepSize >> 2); + + if(EncodedSample & 0x08) + Difference += (StepSize >> 3); + + if(EncodedSample & 0x10) + Difference += (StepSize >> 4); + + if(EncodedSample & 0x20) + Difference += (StepSize >> 5); + + return UpdatePredictedSample(PredictedSample, EncodedSample, Difference); +} + +//---------------------------------------------------------------------------- +// Compression routine + +int CompressADPCM(void * pvOutBuffer, int cbOutBuffer, void * pvInBuffer, int cbInBuffer, int ChannelCount, int CompressionLevel) +{ + TADPCMStream os(pvOutBuffer, cbOutBuffer); // The output stream + TADPCMStream is(pvInBuffer, cbInBuffer); // The input stream + unsigned char BitShift = (unsigned char)(CompressionLevel - 1); + short PredictedSamples[MAX_ADPCM_CHANNEL_COUNT];// Predicted samples for each channel + short StepIndexes[MAX_ADPCM_CHANNEL_COUNT]; // Step indexes for each channel + short InputSample; // Input sample for the current channel + int TotalStepSize; + int ChannelIndex; + int AbsDifference; + int Difference; + int MaxBitMask; + int StepSize; + +// _tprintf(_T("== CMPR Started ==============\n")); + + // First byte in the output stream contains zero. The second one contains the compression level + os.WriteByteSample(0); + if(!os.WriteByteSample(BitShift)) + return 2; + + // Set the initial step index for each channel + StepIndexes[0] = StepIndexes[1] = INITIAL_ADPCM_STEP_INDEX; + + // Next, InitialSample value for each channel follows + for(int i = 0; i < ChannelCount; i++) + { + // Get the initial sample from the input stream + if(!is.ReadWordSample(InputSample)) + return os.LengthProcessed(pvOutBuffer); + + // Store the initial sample to our sample array + PredictedSamples[i] = InputSample; + + // Also store the loaded sample to the output stream + if(!os.WriteWordSample(InputSample)) + return os.LengthProcessed(pvOutBuffer); + } + + // Get the initial index + ChannelIndex = ChannelCount - 1; + + // Now keep reading the input data as long as there is something in the input buffer + while(is.ReadWordSample(InputSample)) + { + int EncodedSample = 0; + + // If we have two channels, we need to flip the channel index + ChannelIndex = (ChannelIndex + 1) % ChannelCount; + + // Get the difference from the previous sample. + // If the difference is negative, set the sign bit to the encoded sample + AbsDifference = InputSample - PredictedSamples[ChannelIndex]; + if(AbsDifference < 0) + { + AbsDifference = -AbsDifference; + EncodedSample |= 0x40; + } + + // If the difference is too low (higher that difference treshold), + // write a step index modifier marker + StepSize = StepSizeTable[StepIndexes[ChannelIndex]]; + if(AbsDifference < (StepSize >> CompressionLevel)) + { + if(StepIndexes[ChannelIndex] != 0) + StepIndexes[ChannelIndex]--; + + os.WriteByteSample(0x80); + } + else + { + // If the difference is too high, write marker that + // indicates increase in step size + while(AbsDifference > (StepSize << 1)) + { + if(StepIndexes[ChannelIndex] >= 0x58) + break; + + // Modify the step index + StepIndexes[ChannelIndex] += 8; + if(StepIndexes[ChannelIndex] > 0x58) + StepIndexes[ChannelIndex] = 0x58; + + // Write the "modify step index" marker + StepSize = StepSizeTable[StepIndexes[ChannelIndex]]; + os.WriteByteSample(0x81); + } + + // Get the limit bit value + MaxBitMask = (1 << (BitShift - 1)); + MaxBitMask = (MaxBitMask > 0x20) ? 0x20 : MaxBitMask; + Difference = StepSize >> BitShift; + TotalStepSize = 0; + + for(int BitVal = 0x01; BitVal <= MaxBitMask; BitVal <<= 1) + { + if((TotalStepSize + StepSize) <= AbsDifference) + { + TotalStepSize += StepSize; + EncodedSample |= BitVal; + } + StepSize >>= 1; + } + + PredictedSamples[ChannelIndex] = (short)UpdatePredictedSample(PredictedSamples[ChannelIndex], + EncodedSample, + Difference + TotalStepSize); + // Write the encoded sample to the output stream + if(!os.WriteByteSample((unsigned char)EncodedSample)) + break; + + // Calculates the step index to use for the next encode + StepIndexes[ChannelIndex] = GetNextStepIndex(StepIndexes[ChannelIndex], EncodedSample); + } + } + +// _tprintf(_T("== CMPR Ended ================\n")); + return os.LengthProcessed(pvOutBuffer); +} + +//---------------------------------------------------------------------------- +// Decompression routine + +int DecompressADPCM(void * pvOutBuffer, int cbOutBuffer, void * pvInBuffer, int cbInBuffer, int ChannelCount) +{ + TADPCMStream os(pvOutBuffer, cbOutBuffer); // Output stream + TADPCMStream is(pvInBuffer, cbInBuffer); // Input stream + unsigned char EncodedSample; + unsigned char BitShift; + short PredictedSamples[MAX_ADPCM_CHANNEL_COUNT]; // Predicted sample for each channel + short StepIndexes[MAX_ADPCM_CHANNEL_COUNT]; // Predicted step index for each channel + int ChannelIndex; // Current channel index + + // Initialize the StepIndex for each channel + StepIndexes[0] = StepIndexes[1] = INITIAL_ADPCM_STEP_INDEX; + +// _tprintf(_T("== DCMP Started ==============\n")); + + // The first byte is always zero, the second one contains bit shift (compression level - 1) + is.ReadByteSample(BitShift); + is.ReadByteSample(BitShift); +// _tprintf(_T("DCMP: BitShift = %u\n"), (unsigned int)(unsigned char)BitShift); + + // Next, InitialSample value for each channel follows + for(int i = 0; i < ChannelCount; i++) + { + // Get the initial sample from the input stream + short InitialSample; + + // Attempt to read the initial sample + if(!is.ReadWordSample(InitialSample)) + return os.LengthProcessed(pvOutBuffer); + +// _tprintf(_T("DCMP: Loaded InitialSample[%u]: %04X\n"), i, (unsigned int)(unsigned short)InitialSample); + + // Store the initial sample to our sample array + PredictedSamples[i] = InitialSample; + + // Also store the loaded sample to the output stream + if(!os.WriteWordSample(InitialSample)) + return os.LengthProcessed(pvOutBuffer); + } + + // Get the initial index + ChannelIndex = ChannelCount - 1; + + // Keep reading as long as there is something in the input buffer + while(is.ReadByteSample(EncodedSample)) + { +// _tprintf(_T("DCMP: Loaded Encoded Sample: %02X\n"), (unsigned int)(unsigned char)EncodedSample); + + // If we have two channels, we need to flip the channel index + ChannelIndex = (ChannelIndex + 1) % ChannelCount; + + if(EncodedSample == 0x80) + { + if(StepIndexes[ChannelIndex] != 0) + StepIndexes[ChannelIndex]--; + +// _tprintf(_T("DCMP: Writing Decoded Sample: %04lX\n"), (unsigned int)(unsigned short)PredictedSamples[ChannelIndex]); + if(!os.WriteWordSample(PredictedSamples[ChannelIndex])) + return os.LengthProcessed(pvOutBuffer); + } + else if(EncodedSample == 0x81) + { + // Modify the step index + StepIndexes[ChannelIndex] += 8; + if(StepIndexes[ChannelIndex] > 0x58) + StepIndexes[ChannelIndex] = 0x58; + +// _tprintf(_T("DCMP: New value of StepIndex: %04lX\n"), (unsigned int)(unsigned short)StepIndexes[ChannelIndex]); + + // Next pass, keep going on the same channel + ChannelIndex = (ChannelIndex + 1) % ChannelCount; + } + else + { + int StepIndex = StepIndexes[ChannelIndex]; + int StepSize = StepSizeTable[StepIndex]; + + // Encode one sample + PredictedSamples[ChannelIndex] = (short)DecodeSample(PredictedSamples[ChannelIndex], + EncodedSample, + StepSize, + StepSize >> BitShift); + +// _tprintf(_T("DCMP: Writing decoded sample: %04X\n"), (unsigned int)(unsigned short)PredictedSamples[ChannelIndex]); + + // Write the decoded sample to the output stream + if(!os.WriteWordSample(PredictedSamples[ChannelIndex])) + break; + + // Calculates the step index to use for the next encode + StepIndexes[ChannelIndex] = GetNextStepIndex(StepIndex, EncodedSample); +// _tprintf(_T("DCMP: New step index: %04X\n"), (unsigned int)(unsigned short)StepIndexes[ChannelIndex]); + } + } + +// _tprintf(_T("DCMP: Total length written: %u\n"), (unsigned int)os.LengthProcessed(pvOutBuffer)); +// _tprintf(_T("== DCMP Ended ================\n")); + + // Return total bytes written since beginning of the output buffer + return os.LengthProcessed(pvOutBuffer); +} |