diff options
Diffstat (limited to 'Src/adpcm/avi_ima_adpcm_decoder.cpp')
| -rw-r--r-- | Src/adpcm/avi_ima_adpcm_decoder.cpp | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/Src/adpcm/avi_ima_adpcm_decoder.cpp b/Src/adpcm/avi_ima_adpcm_decoder.cpp new file mode 100644 index 00000000..5050a66d --- /dev/null +++ b/Src/adpcm/avi_ima_adpcm_decoder.cpp @@ -0,0 +1,236 @@ +#include "avi_ima_adpcm_decoder.h" +#include "../f263/BitReader.h" + +#pragma pack(push, 1) +struct ima_adpcm_format +{ + nsavi::audio_format format; + uint16_t samples_per_block; +}; +#pragma pack(pop) + +IMA_ADPCM_AVIDecoder::IMA_ADPCM_AVIDecoder(const ima_adpcm_format *adpcmformat, const nsavi::STRH *stream_header) : adpcmformat(adpcmformat), stream_header(stream_header) +{ +} + +int IMA_ADPCM_AVIDecoder::OutputFrameSize(size_t *frame_size) +{ + int channels = adpcmformat->format.channels; + *frame_size = ((adpcmformat->format.block_align - 7*channels)*2 + 2*channels) * 2; + return AVI_SUCCESS; +} + +int IMA_ADPCM_AVIDecoder::GetOutputProperties(unsigned int *sampleRate, unsigned int *channels, unsigned int *bitsPerSample, bool *isFloat) +{ + if (adpcmformat) + { + *sampleRate = adpcmformat->format.sample_rate; + *channels = adpcmformat->format.channels; + *bitsPerSample = 16; + *isFloat = false; + return AVI_SUCCESS; + } + else + { + return AVI_FAILURE; + } +} + +static int index_table[16] = { + -1, -1, -1, -1, 2, 4, 6, 8, + -1, -1, -1, -1, 2, 4, 6, 8 +}; + +static int step_table[89] = { + 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 +}; + +int IMA_ADPCM_AVIDecoder::DecodeChunk(uint16_t type, void **inputBuffer, size_t *inputBufferBytes, void *outputBuffer, size_t *outputBufferBytes) +{ + if (adpcmformat->format.channels == 1) + { + size_t adpcm_stream_length = *inputBufferBytes; + if (adpcm_stream_length < adpcmformat->format.block_align) // i'm not even going to consider the possibility of adpcm frames split across avi chunks + return AVI_FAILURE; + + adpcm_stream_length = adpcmformat->format.block_align; // do one block at a time, in_avi will call us again + + if (adpcm_stream_length < 7) + return AVI_FAILURE; + + int16_t *out16 = (int16_t *)outputBuffer; + size_t out16_length = *outputBufferBytes/2; + + const uint8_t *adpcm_data = (const uint8_t *)(*inputBuffer); + + int predictor = *(int16_t *)adpcm_data; + *out16++ = predictor; + adpcm_data+=2; + out16_length--; + int step_index = *adpcm_data; + if (step_index > 88) + return AVI_FAILURE; + adpcm_data+=2; + + BitReader reader; + reader.data = adpcm_data; + reader.numBits = (uint32_t)(*inputBufferBytes - 4)*8; + + while (reader.numBits >= 8 && out16_length) + { + int diff, step, nibble; + + step = step_table[step_index]; + nibble = reader.getbits(4); + step_index += index_table[nibble]; + step_index = min(step_index, 88); + step_index = max(step_index, 0); + + diff = step>>3; + if(nibble&4) + diff += step; + if(nibble&2) + diff += step>>1; + if(nibble&1) + diff += step>>2; + + if (nibble&8) + predictor -= diff; + else + predictor += diff; + predictor = min(predictor, 32767); + predictor = max(predictor, -32768); + *out16++ = predictor; + out16_length--; + } + *inputBuffer = (uint8_t *)(*inputBuffer) + adpcm_stream_length; + *inputBufferBytes -= adpcm_stream_length; + *outputBufferBytes = adpcmformat->samples_per_block*2; + return AVI_SUCCESS; + } + else if (adpcmformat->format.channels == 2) + { + size_t adpcm_stream_length = *inputBufferBytes; + if (adpcm_stream_length < adpcmformat->format.block_align) // i'm not even going to consider the possibility of adpcm frames split across avi chunks + return AVI_FAILURE; + + adpcm_stream_length = adpcmformat->format.block_align; // do one block at a time, in_avi will call us again + + if (adpcm_stream_length < 8) + return AVI_FAILURE; + + int16_t *out16 = (int16_t *)outputBuffer; + size_t out16_length = *outputBufferBytes/2; + + const uint8_t *adpcm_data = (const uint8_t *)(*inputBuffer); + + int predictor_left = *(int16_t *)adpcm_data; + *out16++ = predictor_left; + adpcm_data+=2; + out16_length--; + int step_index_left = *adpcm_data; + if (step_index_left > 88) + return AVI_FAILURE; + adpcm_data+=2; + + int predictor_right = *(int16_t *)adpcm_data; + *out16++ = predictor_right; + adpcm_data+=2; + out16_length--; + int step_index_right = *adpcm_data; + if (step_index_right > 88) + return AVI_FAILURE; + adpcm_data+=2; + + BitReader reader; + reader.data = adpcm_data; + reader.numBits = (uint32_t)(*inputBufferBytes - 8)*8; + + while (reader.numBits >= 8 && out16_length > 15) + { + int nibbles_left[8] = {0}; + int nibbles_right[8] = {0}; + for (int i=0;i<8;i++) + nibbles_left[i] = reader.getbits(4); + + for (int i=0;i<8;i++) + nibbles_right[i] = reader.getbits(4); + + for (int i=0;i<8;i++) + { + int diff, step, nibble; + step = step_table[step_index_left]; + nibble = nibbles_left[i]; + step_index_left += index_table[nibble]; + step_index_left = min(step_index_left, 88); + step_index_left = max(step_index_left, 0); + + diff = step>>3; + if(nibble&4) + diff += step; + if(nibble&2) + diff += step>>1; + if(nibble&1) + diff += step>>2; + + if (nibble&8) + predictor_left -= diff; + else + predictor_left += diff; + predictor_left = min(predictor_left, 32767); + predictor_left = max(predictor_left, -32768); + *out16++ = predictor_left; + out16_length--; + + step = step_table[step_index_right]; + nibble =nibbles_right[i]; + step_index_right += index_table[nibble]; + step_index_right = min(step_index_right, 88); + step_index_right = max(step_index_right, 0); + diff = step>>3; + if(nibble&4) + diff += step; + if(nibble&2) + diff += step>>1; + if(nibble&1) + diff += step>>2; + if (nibble&8) + predictor_right -= diff; + else + predictor_right += diff; + predictor_right = min(predictor_right, 32767); + predictor_right = max(predictor_right, -32768); + *out16++ = predictor_right; + out16_length--; + } + } + *inputBuffer = (uint8_t *)(*inputBuffer) + adpcm_stream_length; + *inputBufferBytes -= adpcm_stream_length; + *outputBufferBytes = adpcmformat->samples_per_block*4; + return AVI_SUCCESS; + } + + return AVI_FAILURE; +} + +void IMA_ADPCM_AVIDecoder::Close() +{ + delete this; +} + +#define CBCLASS IMA_ADPCM_AVIDecoder +START_DISPATCH; +CB(OUTPUT_FRAME_SIZE, OutputFrameSize) +CB(GET_OUTPUT_PROPERTIES, GetOutputProperties) +CB(DECODE_CHUNK, DecodeChunk) +VCB(CLOSE, Close) +END_DISPATCH; +#undef CBCLASS
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