| 0,0 → 1,155 |
|---|
| /* |
| layer1.c: the layer 1 decoder |
| |
| copyright 1995-2008 by the mpg123 project - free software under the terms of the LGPL 2.1 |
| see COPYING and AUTHORS files in distribution or http://mpg123.org |
| initially written by Michael Hipp |
| |
| may have a few bugs after last optimization ... |
| */ |
| |
| #include "mpg123lib_intern.h" |
| #include "getbits.h" |
| |
| void I_step_one(unsigned int balloc[], unsigned int scale_index[2][SBLIMIT],mpg123_handle *fr) |
| { |
| unsigned int *ba=balloc; |
| unsigned int *sca = (unsigned int *) scale_index; |
| |
| if(fr->stereo == 2) |
| { |
| int i; |
| int jsbound = fr->jsbound; |
| for(i=0;i<jsbound;i++) |
| { |
| *ba++ = getbits(fr, 4); |
| *ba++ = getbits(fr, 4); |
| } |
| for(i=jsbound;i<SBLIMIT;i++) *ba++ = getbits(fr, 4); |
| |
| ba = balloc; |
| |
| for(i=0;i<jsbound;i++) |
| { |
| if ((*ba++)) |
| *sca++ = getbits(fr, 6); |
| if ((*ba++)) |
| *sca++ = getbits(fr, 6); |
| } |
| for (i=jsbound;i<SBLIMIT;i++) |
| if((*ba++)) |
| { |
| *sca++ = getbits(fr, 6); |
| *sca++ = getbits(fr, 6); |
| } |
| } |
| else |
| { |
| int i; |
| for(i=0;i<SBLIMIT;i++) *ba++ = getbits(fr, 4); |
| |
| ba = balloc; |
| for (i=0;i<SBLIMIT;i++) |
| if ((*ba++)) |
| *sca++ = getbits(fr, 6); |
| } |
| } |
| |
| void I_step_two(real fraction[2][SBLIMIT],unsigned int balloc[2*SBLIMIT], unsigned int scale_index[2][SBLIMIT],mpg123_handle *fr) |
| { |
| int i,n; |
| int smpb[2*SBLIMIT]; /* values: 0-65535 */ |
| int *sample; |
| register unsigned int *ba; |
| register unsigned int *sca = (unsigned int *) scale_index; |
| |
| if(fr->stereo == 2) |
| { |
| int jsbound = fr->jsbound; |
| register real *f0 = fraction[0]; |
| register real *f1 = fraction[1]; |
| ba = balloc; |
| for(sample=smpb,i=0;i<jsbound;i++) |
| { |
| if((n = *ba++)) *sample++ = getbits(fr, n+1); |
| |
| if((n = *ba++)) *sample++ = getbits(fr, n+1); |
| } |
| for(i=jsbound;i<SBLIMIT;i++) |
| if((n = *ba++)) |
| *sample++ = getbits(fr, n+1); |
| |
| ba = balloc; |
| for(sample=smpb,i=0;i<jsbound;i++) |
| { |
| if((n=*ba++)) |
| *f0++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1), fr->muls[n+1][*sca++]); |
| else *f0++ = DOUBLE_TO_REAL(0.0); |
| |
| if((n=*ba++)) |
| *f1++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1), fr->muls[n+1][*sca++]); |
| else *f1++ = DOUBLE_TO_REAL(0.0); |
| } |
| for(i=jsbound;i<SBLIMIT;i++) |
| { |
| if((n=*ba++)) |
| { |
| real samp = DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1); |
| *f0++ = REAL_MUL_SCALE_LAYER12(samp, fr->muls[n+1][*sca++]); |
| *f1++ = REAL_MUL_SCALE_LAYER12(samp, fr->muls[n+1][*sca++]); |
| } |
| else *f0++ = *f1++ = DOUBLE_TO_REAL(0.0); |
| } |
| for(i=fr->down_sample_sblimit;i<32;i++) |
| fraction[0][i] = fraction[1][i] = 0.0; |
| } |
| else |
| { |
| register real *f0 = fraction[0]; |
| ba = balloc; |
| for(sample=smpb,i=0;i<SBLIMIT;i++) |
| if ((n = *ba++)) |
| *sample++ = getbits(fr, n+1); |
| |
| ba = balloc; |
| for(sample=smpb,i=0;i<SBLIMIT;i++) |
| { |
| if((n=*ba++)) |
| *f0++ = REAL_MUL_SCALE_LAYER12(DOUBLE_TO_REAL_15( ((-1)<<n) + (*sample++) + 1), fr->muls[n+1][*sca++]); |
| else *f0++ = DOUBLE_TO_REAL(0.0); |
| } |
| for(i=fr->down_sample_sblimit;i<32;i++) |
| fraction[0][i] = DOUBLE_TO_REAL(0.0); |
| } |
| } |
| |
| int do_layer1(mpg123_handle *fr) |
| { |
| int clip=0; |
| int i,stereo = fr->stereo; |
| unsigned int balloc[2*SBLIMIT]; |
| unsigned int scale_index[2][SBLIMIT]; |
| ALIGNED(16) real fraction[2][SBLIMIT]; |
| int single = fr->single; |
| |
| fr->jsbound = (fr->mode == MPG_MD_JOINT_STEREO) ? (fr->mode_ext<<2)+4 : 32; |
| |
| if(stereo == 1 || single == SINGLE_MIX) /* I don't see mixing handled here */ |
| single = SINGLE_LEFT; |
| |
| I_step_one(balloc,scale_index,fr); |
| |
| for(i=0;i<SCALE_BLOCK;i++) |
| { |
| I_step_two(fraction,balloc,scale_index,fr); |
| |
| if(single != SINGLE_STEREO) |
| clip += (fr->synth_mono)(fraction[single], fr); |
| else |
| clip += (fr->synth_stereo)(fraction[0], fraction[1], fr); |
| } |
| |
| return clip; |
| } |
| |
| |