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https://github.com/vgmstream/vgmstream.git
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1eba859222
changed _noninterleaved functions to _int and changed related descriptions appropriately added an _int version of SDX2 and reverted to pre-322 behavior for normal deocder made the various get_high_nibble globals all be the same vgmstream->get_high_nibble for thread safety and code consolidation (this required some changes to make decode functions take VGMSTREAM rather than VGMSTREAMCHANNEL) git-svn-id: https://vgmstream.svn.sourceforge.net/svnroot/vgmstream@323 51a99a44-fe44-0410-b1ba-c3e57ba2b86b
73 lines
2.1 KiB
C
73 lines
2.1 KiB
C
#include "coding.h"
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#include "../util.h"
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const int SH = 4;
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const int SHC = 10;
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double K0[4] = { 0.0, 0.9375, 1.796875, 1.53125};
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double K1[4] = { 0.0, 0.0, -0.8125,-0.859375};
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int IK0(int fid)
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{ return ((int)((-K0[fid]) * (1 << SHC))); }
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int IK1(int fid)
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{ return ((int)((-K1[fid]) * (1 << SHC))); }
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int CLAMP(int value, int Minim, int Maxim)
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{
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if (value < Minim) value = Minim;
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if (value > Maxim) value = Maxim;
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return value;
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}
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void init_get_high_nibble(VGMSTREAM *vgmstream) {
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vgmstream->get_high_nibble=1;
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}
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void decode_xa(VGMSTREAM * vgmstream, sample * outbuf, int channelspacing, int32_t first_sample, int32_t samples_to_do, int channel) {
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VGMSTREAMCHANNEL * stream = &(vgmstream->ch[channel]);
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int predict_nr, shift_factor, sample;
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int32_t hist1=stream->adpcm_history1_32;
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int32_t hist2=stream->adpcm_history2_32;
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int HeadTable[8]={0,2,8,10};
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short scale;
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int i;
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int32_t sample_count;
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int framesin = first_sample / (56 / channelspacing);
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first_sample = first_sample % 28;
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vgmstream->get_high_nibble=!vgmstream->get_high_nibble;
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if((first_sample) && (channelspacing==1))
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vgmstream->get_high_nibble=!vgmstream->get_high_nibble;
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predict_nr = read_8bit(stream->offset+HeadTable[framesin]+vgmstream->get_high_nibble,stream->streamfile) >> 4;
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shift_factor = read_8bit(stream->offset+HeadTable[framesin]+vgmstream->get_high_nibble,stream->streamfile) & 0xf;
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for (i=first_sample,sample_count=0; i<first_sample+samples_to_do; i++,sample_count+=channelspacing) {
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short sample_byte = (short)read_8bit(stream->offset+16+framesin+(i*4),stream->streamfile);
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scale = ((vgmstream->get_high_nibble ?
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sample_byte >> 4 :
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sample_byte & 0x0f)<<12);
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sample = (short)(scale & 0xf000) >> shift_factor;
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sample <<= SH;
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sample -= (IK0(predict_nr) * hist1 + (IK1(predict_nr) * hist2)) >> SHC;
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hist2=hist1;
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hist1=sample;
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sample = CLAMP(sample, -32768 << SH, 32767 << SH);
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outbuf[sample_count] = (short)(sample >> SH);
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}
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stream->adpcm_history1_32=hist1;
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stream->adpcm_history2_32=hist2;
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}
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