michael@0: /********************************************************************
michael@0:  *                                                                  *
michael@0:  * THIS FILE IS PART OF THE OggVorbis 'TREMOR' CODEC SOURCE CODE.   *
michael@0:  *                                                                  *
michael@0:  * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS     *
michael@0:  * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
michael@0:  * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING.       *
michael@0:  *                                                                  *
michael@0:  * THE OggVorbis 'TREMOR' SOURCE CODE IS (C) COPYRIGHT 1994-2002    *
michael@0:  * BY THE Xiph.Org FOUNDATION http://www.xiph.org/                  *
michael@0:  *                                                                  *
michael@0:  ********************************************************************
michael@0: 
michael@0:  function: floor backend 0 implementation
michael@0: 
michael@0:  ********************************************************************/
michael@0: 
michael@0: #include <stdlib.h>
michael@0: #include <string.h>
michael@0: #include <math.h>
michael@0: #include <ogg/ogg.h>
michael@0: #include "ivorbiscodec.h"
michael@0: #include "codec_internal.h"
michael@0: #include "registry.h"
michael@0: #include "codebook.h"
michael@0: #include "misc.h"
michael@0: #include "block.h"
michael@0: 
michael@0: #define LSP_FRACBITS 14
michael@0: 
michael@0: typedef struct {
michael@0:   long n;
michael@0:   int ln;
michael@0:   int  m;
michael@0:   int *linearmap;
michael@0: 
michael@0:   vorbis_info_floor0 *vi;
michael@0:   ogg_int32_t *lsp_look;
michael@0: 
michael@0: } vorbis_look_floor0;
michael@0: 
michael@0: /*************** LSP decode ********************/
michael@0: 
michael@0: #include "lsp_lookup.h"
michael@0: 
michael@0: /* interpolated 1./sqrt(p) where .5 <= a < 1. (.100000... to .111111...) in
michael@0:    16.16 format 
michael@0:    returns in m.8 format */
michael@0: 
michael@0: static long ADJUST_SQRT2[2]={8192,5792};
michael@0: STIN ogg_int32_t vorbis_invsqlook_i(long a,long e){
michael@0:   long i=(a&0x7fff)>>(INVSQ_LOOKUP_I_SHIFT-1); 
michael@0:   long d=a&INVSQ_LOOKUP_I_MASK;                              /*  0.10 */
michael@0:   long val=INVSQ_LOOKUP_I[i]-                                /*  1.16 */
michael@0:     ((INVSQ_LOOKUP_IDel[i]*d)>>INVSQ_LOOKUP_I_SHIFT);        /* result 1.16 */
michael@0:   val*=ADJUST_SQRT2[e&1];
michael@0:   e=(e>>1)+21;
michael@0:   return(val>>e);
michael@0: }
michael@0: 
michael@0: /* interpolated lookup based fromdB function, domain -140dB to 0dB only */
michael@0: /* a is in n.12 format */
michael@0: STIN ogg_int32_t vorbis_fromdBlook_i(long a){
michael@0:   int i=(-a)>>(12-FROMdB2_SHIFT);
michael@0:   if(i<0) return 0x7fffffff;
michael@0:   if(i>=(FROMdB_LOOKUP_SZ<<FROMdB_SHIFT))return 0;
michael@0:   
michael@0:   return FROMdB_LOOKUP[i>>FROMdB_SHIFT] * FROMdB2_LOOKUP[i&FROMdB2_MASK];
michael@0: }
michael@0: 
michael@0: /* interpolated lookup based cos function, domain 0 to PI only */
michael@0: /* a is in 0.16 format, where 0==0, 2^^16-1==PI, return 0.14 */
michael@0: STIN ogg_int32_t vorbis_coslook_i(long a){
michael@0:   int i=a>>COS_LOOKUP_I_SHIFT;
michael@0:   int d=a&COS_LOOKUP_I_MASK;
michael@0:   return COS_LOOKUP_I[i]- ((d*(COS_LOOKUP_I[i]-COS_LOOKUP_I[i+1]))>>
michael@0: 			   COS_LOOKUP_I_SHIFT);
michael@0: }
michael@0: 
michael@0: /* interpolated lookup based cos function */
michael@0: /* a is in 0.16 format, where 0==0, 2^^16==PI, return .LSP_FRACBITS */
michael@0: STIN ogg_int32_t vorbis_coslook2_i(long a){
michael@0:   a=a&0x1ffff;
michael@0: 
michael@0:   if(a>0x10000)a=0x20000-a;
michael@0:   {               
michael@0:     int i=a>>COS_LOOKUP_I_SHIFT;
michael@0:     int d=a&COS_LOOKUP_I_MASK;
michael@0:     a=((COS_LOOKUP_I[i]<<COS_LOOKUP_I_SHIFT)-
michael@0:        d*(COS_LOOKUP_I[i]-COS_LOOKUP_I[i+1]))>>
michael@0:       (COS_LOOKUP_I_SHIFT-LSP_FRACBITS+14);
michael@0:   }
michael@0:   
michael@0:   return(a);
michael@0: }
michael@0: 
michael@0: static const int barklook[28]={
michael@0:   0,100,200,301,          405,516,635,766,
michael@0:   912,1077,1263,1476,     1720,2003,2333,2721,
michael@0:   3184,3742,4428,5285,    6376,7791,9662,12181,
michael@0:   15624,20397,27087,36554
michael@0: };
michael@0: 
michael@0: /* used in init only; interpolate the long way */
michael@0: STIN ogg_int32_t toBARK(int n){
michael@0:   int i;
michael@0:   for(i=0;i<27;i++) 
michael@0:     if(n>=barklook[i] && n<barklook[i+1])break;
michael@0:   
michael@0:   if(i==27){
michael@0:     return 27<<15;
michael@0:   }else{
michael@0:     int gap=barklook[i+1]-barklook[i];
michael@0:     int del=n-barklook[i];
michael@0: 
michael@0:     return((i<<15)+((del<<15)/gap));
michael@0:   }
michael@0: }
michael@0: 
michael@0: static const unsigned char MLOOP_1[64]={
michael@0:    0,10,11,11, 12,12,12,12, 13,13,13,13, 13,13,13,13,
michael@0:   14,14,14,14, 14,14,14,14, 14,14,14,14, 14,14,14,14,
michael@0:   15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
michael@0:   15,15,15,15, 15,15,15,15, 15,15,15,15, 15,15,15,15,
michael@0: };
michael@0: 
michael@0: static const unsigned char MLOOP_2[64]={
michael@0:   0,4,5,5, 6,6,6,6, 7,7,7,7, 7,7,7,7,
michael@0:   8,8,8,8, 8,8,8,8, 8,8,8,8, 8,8,8,8,
michael@0:   9,9,9,9, 9,9,9,9, 9,9,9,9, 9,9,9,9,
michael@0:   9,9,9,9, 9,9,9,9, 9,9,9,9, 9,9,9,9,
michael@0: };
michael@0: 
michael@0: static const unsigned char MLOOP_3[8]={0,1,2,2,3,3,3,3};
michael@0: 
michael@0: void vorbis_lsp_to_curve(ogg_int32_t *curve,int *map,int n,int ln,
michael@0: 			 ogg_int32_t *lsp,int m,
michael@0: 			 ogg_int32_t amp,
michael@0: 			 ogg_int32_t ampoffset,
michael@0: 			 ogg_int32_t *icos){
michael@0: 
michael@0:   /* 0 <= m < 256 */
michael@0: 
michael@0:   /* set up for using all int later */
michael@0:   int i;
michael@0:   int ampoffseti=ampoffset*4096;
michael@0:   int ampi=amp;
michael@0:   ogg_int32_t *ilsp=(ogg_int32_t *)alloca(m*sizeof(*ilsp));
michael@0:   /* lsp is in 8.24, range 0 to PI; coslook wants it in .16 0 to 1*/
michael@0:   for(i=0;i<m;i++){
michael@0: #ifndef _LOW_ACCURACY_
michael@0:     ogg_int32_t val=MULT32(lsp[i],0x517cc2);
michael@0: #else
michael@0:     ogg_int32_t val=((lsp[i]>>10)*0x517d)>>14;
michael@0: #endif
michael@0: 
michael@0:     /* safeguard against a malicious stream */
michael@0:     if(val<0 || (val>>COS_LOOKUP_I_SHIFT)>=COS_LOOKUP_I_SZ){
michael@0:       memset(curve,0,sizeof(*curve)*n);
michael@0:       return;
michael@0:     }
michael@0: 
michael@0:     ilsp[i]=vorbis_coslook_i(val);
michael@0:   }
michael@0: 
michael@0:   i=0;
michael@0:   while(i<n){
michael@0:     int j,k=map[i];
michael@0:     ogg_uint32_t pi=46341; /* 2**-.5 in 0.16 */
michael@0:     ogg_uint32_t qi=46341;
michael@0:     ogg_int32_t qexp=0,shift;
michael@0:     ogg_int32_t wi=icos[k];
michael@0: 
michael@0: #ifdef _V_LSP_MATH_ASM
michael@0:     lsp_loop_asm(&qi,&pi,&qexp,ilsp,wi,m);
michael@0: 
michael@0:     pi=((pi*pi)>>16);
michael@0:     qi=((qi*qi)>>16);
michael@0:     
michael@0:     if(m&1){
michael@0:       qexp= qexp*2-28*((m+1)>>1)+m;	     
michael@0:       pi*=(1<<14)-((wi*wi)>>14);
michael@0:       qi+=pi>>14;     
michael@0:     }else{
michael@0:       qexp= qexp*2-13*m;
michael@0:       
michael@0:       pi*=(1<<14)-wi;
michael@0:       qi*=(1<<14)+wi;
michael@0:       
michael@0:       qi=(qi+pi)>>14;
michael@0:     }
michael@0:     
michael@0:     if(qi&0xffff0000){ /* checks for 1.xxxxxxxxxxxxxxxx */
michael@0:       qi>>=1; qexp++; 
michael@0:     }else
michael@0:       lsp_norm_asm(&qi,&qexp);
michael@0: 
michael@0: #else
michael@0: 
michael@0:     j=1;
michael@0:     if(m>1){
michael@0:       qi*=labs(ilsp[0]-wi);
michael@0:       pi*=labs(ilsp[1]-wi);
michael@0: 
michael@0:       for(j+=2;j<m;j+=2){
michael@0:         if(!(shift=MLOOP_1[(pi|qi)>>25]))
michael@0:           if(!(shift=MLOOP_2[(pi|qi)>>19]))
michael@0:             shift=MLOOP_3[(pi|qi)>>16];
michael@0:         qi=(qi>>shift)*labs(ilsp[j-1]-wi);
michael@0:         pi=(pi>>shift)*labs(ilsp[j]-wi);
michael@0:         qexp+=shift;
michael@0:       }
michael@0:     }
michael@0:     if(!(shift=MLOOP_1[(pi|qi)>>25]))
michael@0:       if(!(shift=MLOOP_2[(pi|qi)>>19]))
michael@0: 	shift=MLOOP_3[(pi|qi)>>16];
michael@0: 
michael@0:     /* pi,qi normalized collectively, both tracked using qexp */
michael@0: 
michael@0:     if(m&1){
michael@0:       /* odd order filter; slightly assymetric */
michael@0:       /* the last coefficient */
michael@0:       qi=(qi>>shift)*labs(ilsp[j-1]-wi);
michael@0:       pi=(pi>>shift)<<14;
michael@0:       qexp+=shift;
michael@0: 
michael@0:       if(!(shift=MLOOP_1[(pi|qi)>>25]))
michael@0: 	if(!(shift=MLOOP_2[(pi|qi)>>19]))
michael@0: 	  shift=MLOOP_3[(pi|qi)>>16];
michael@0:       
michael@0:       pi>>=shift;
michael@0:       qi>>=shift;
michael@0:       qexp+=shift-14*((m+1)>>1);
michael@0: 
michael@0:       pi=((pi*pi)>>16);
michael@0:       qi=((qi*qi)>>16);
michael@0:       qexp=qexp*2+m;
michael@0: 
michael@0:       pi*=(1<<14)-((wi*wi)>>14);
michael@0:       qi+=pi>>14;
michael@0: 
michael@0:     }else{
michael@0:       /* even order filter; still symmetric */
michael@0: 
michael@0:       /* p*=p(1-w), q*=q(1+w), let normalization drift because it isn't
michael@0: 	 worth tracking step by step */
michael@0:       
michael@0:       pi>>=shift;
michael@0:       qi>>=shift;
michael@0:       qexp+=shift-7*m;
michael@0: 
michael@0:       pi=((pi*pi)>>16);
michael@0:       qi=((qi*qi)>>16);
michael@0:       qexp=qexp*2+m;
michael@0:       
michael@0:       pi*=(1<<14)-wi;
michael@0:       qi*=(1<<14)+wi;
michael@0:       qi=(qi+pi)>>14;
michael@0:       
michael@0:     }
michael@0:     
michael@0: 
michael@0:     /* we've let the normalization drift because it wasn't important;
michael@0:        however, for the lookup, things must be normalized again.  We
michael@0:        need at most one right shift or a number of left shifts */
michael@0: 
michael@0:     if(qi&0xffff0000){ /* checks for 1.xxxxxxxxxxxxxxxx */
michael@0:       qi>>=1; qexp++; 
michael@0:     }else
michael@0:       while(qi && !(qi&0x8000)){ /* checks for 0.0xxxxxxxxxxxxxxx or less*/
michael@0: 	qi<<=1; qexp--; 
michael@0:       }
michael@0: 
michael@0: #endif
michael@0: 
michael@0:     amp=vorbis_fromdBlook_i(ampi*                     /*  n.4         */
michael@0: 			    vorbis_invsqlook_i(qi,qexp)- 
michael@0: 			                              /*  m.8, m+n<=8 */
michael@0: 			    ampoffseti);              /*  8.12[0]     */
michael@0:     
michael@0: #ifdef _LOW_ACCURACY_
michael@0:     amp>>=9;
michael@0: #endif
michael@0:     curve[i]= MULT31_SHIFT15(curve[i],amp);
michael@0:     while(map[++i]==k) curve[i]= MULT31_SHIFT15(curve[i],amp);
michael@0:   }
michael@0: }
michael@0: 
michael@0: /*************** vorbis decode glue ************/
michael@0: 
michael@0: static void floor0_free_info(vorbis_info_floor *i){
michael@0:   vorbis_info_floor0 *info=(vorbis_info_floor0 *)i;
michael@0:   if(info){
michael@0:     memset(info,0,sizeof(*info));
michael@0:     _ogg_free(info);
michael@0:   }
michael@0: }
michael@0: 
michael@0: static void floor0_free_look(vorbis_look_floor *i){
michael@0:   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
michael@0:   if(look){
michael@0: 
michael@0:     if(look->linearmap)_ogg_free(look->linearmap);
michael@0:     if(look->lsp_look)_ogg_free(look->lsp_look);
michael@0:     memset(look,0,sizeof(*look));
michael@0:     _ogg_free(look);
michael@0:   }
michael@0: }
michael@0: 
michael@0: static vorbis_info_floor *floor0_unpack (vorbis_info *vi,oggpack_buffer *opb){
michael@0:   codec_setup_info     *ci=(codec_setup_info *)vi->codec_setup;
michael@0:   int j;
michael@0: 
michael@0:   vorbis_info_floor0 *info=(vorbis_info_floor0 *)_ogg_malloc(sizeof(*info));
michael@0:   info->order=oggpack_read(opb,8);
michael@0:   info->rate=oggpack_read(opb,16);
michael@0:   info->barkmap=oggpack_read(opb,16);
michael@0:   info->ampbits=oggpack_read(opb,6);
michael@0:   info->ampdB=oggpack_read(opb,8);
michael@0:   info->numbooks=oggpack_read(opb,4)+1;
michael@0:   
michael@0:   if(info->order<1)goto err_out;
michael@0:   if(info->rate<1)goto err_out;
michael@0:   if(info->barkmap<1)goto err_out;
michael@0:   if(info->numbooks<1)goto err_out;
michael@0:     
michael@0:   for(j=0;j<info->numbooks;j++){
michael@0:     info->books[j]=oggpack_read(opb,8);
michael@0:     if(info->books[j]<0 || info->books[j]>=ci->books)goto err_out;
michael@0:     if(ci->book_param[info->books[j]]->maptype==0)goto err_out;
michael@0:   }
michael@0:   return(info);
michael@0: 
michael@0:  err_out:
michael@0:   floor0_free_info(info);
michael@0:   return(NULL);
michael@0: }
michael@0: 
michael@0: /* initialize Bark scale and normalization lookups.  We could do this
michael@0:    with static tables, but Vorbis allows a number of possible
michael@0:    combinations, so it's best to do it computationally.
michael@0: 
michael@0:    The below is authoritative in terms of defining scale mapping.
michael@0:    Note that the scale depends on the sampling rate as well as the
michael@0:    linear block and mapping sizes */
michael@0: 
michael@0: static vorbis_look_floor *floor0_look (vorbis_dsp_state *vd,vorbis_info_mode *mi,
michael@0:                               vorbis_info_floor *i){
michael@0:   int j;
michael@0:   vorbis_info        *vi=vd->vi;
michael@0:   codec_setup_info   *ci=(codec_setup_info *)vi->codec_setup;
michael@0:   vorbis_info_floor0 *info=(vorbis_info_floor0 *)i;
michael@0:   vorbis_look_floor0 *look=(vorbis_look_floor0 *)_ogg_calloc(1,sizeof(*look));
michael@0:   look->m=info->order;
michael@0:   look->n=ci->blocksizes[mi->blockflag]/2;
michael@0:   look->ln=info->barkmap;
michael@0:   look->vi=info;
michael@0: 
michael@0:   /* the mapping from a linear scale to a smaller bark scale is
michael@0:      straightforward.  We do *not* make sure that the linear mapping
michael@0:      does not skip bark-scale bins; the decoder simply skips them and
michael@0:      the encoder may do what it wishes in filling them.  They're
michael@0:      necessary in some mapping combinations to keep the scale spacing
michael@0:      accurate */
michael@0:   look->linearmap=(int *)_ogg_malloc((look->n+1)*sizeof(*look->linearmap));
michael@0:   for(j=0;j<look->n;j++){
michael@0: 
michael@0:     int val=(look->ln*
michael@0: 	     ((toBARK(info->rate/2*j/look->n)<<11)/toBARK(info->rate/2)))>>11;
michael@0: 
michael@0:     if(val>=look->ln)val=look->ln-1; /* guard against the approximation */
michael@0:     look->linearmap[j]=val;
michael@0:   }
michael@0:   look->linearmap[j]=-1;
michael@0: 
michael@0:   look->lsp_look=(ogg_int32_t *)_ogg_malloc(look->ln*sizeof(*look->lsp_look));
michael@0:   for(j=0;j<look->ln;j++)
michael@0:     look->lsp_look[j]=vorbis_coslook2_i(0x10000*j/look->ln);
michael@0: 
michael@0:   return look;
michael@0: }
michael@0: 
michael@0: static void *floor0_inverse1(vorbis_block *vb,vorbis_look_floor *i){
michael@0:   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
michael@0:   vorbis_info_floor0 *info=look->vi;
michael@0:   int j,k;
michael@0:   
michael@0:   int ampraw=oggpack_read(&vb->opb,info->ampbits);
michael@0:   if(ampraw>0){ /* also handles the -1 out of data case */
michael@0:     long maxval=(1<<info->ampbits)-1;
michael@0:     int amp=((ampraw*info->ampdB)<<4)/maxval;
michael@0:     int booknum=oggpack_read(&vb->opb,_ilog(info->numbooks));
michael@0:     
michael@0:     if(booknum!=-1 && booknum<info->numbooks){ /* be paranoid */
michael@0:       codec_setup_info  *ci=(codec_setup_info *)vb->vd->vi->codec_setup;
michael@0:       codebook *b=ci->fullbooks+info->books[booknum];
michael@0:       ogg_int32_t last=0;
michael@0:       ogg_int32_t *lsp=(ogg_int32_t *)_vorbis_block_alloc(vb,sizeof(*lsp)*(look->m+1));
michael@0:             
michael@0:       if(vorbis_book_decodev_set(b,lsp,&vb->opb,look->m,-24)==-1)goto eop;
michael@0:       for(j=0;j<look->m;){
michael@0: 	for(k=0;j<look->m && k<b->dim;k++,j++)lsp[j]+=last;
michael@0: 	last=lsp[j-1];
michael@0:       }
michael@0:       
michael@0:       lsp[look->m]=amp;
michael@0:       return(lsp);
michael@0:     }
michael@0:   }
michael@0:  eop:
michael@0:   return(NULL);
michael@0: }
michael@0: 
michael@0: static int floor0_inverse2(vorbis_block *vb,vorbis_look_floor *i,
michael@0: 			   void *memo,ogg_int32_t *out){
michael@0:   vorbis_look_floor0 *look=(vorbis_look_floor0 *)i;
michael@0:   vorbis_info_floor0 *info=look->vi;
michael@0:   
michael@0:   if(memo){
michael@0:     ogg_int32_t *lsp=(ogg_int32_t *)memo;
michael@0:     ogg_int32_t amp=lsp[look->m];
michael@0: 
michael@0:     /* take the coefficients back to a spectral envelope curve */
michael@0:     vorbis_lsp_to_curve(out,look->linearmap,look->n,look->ln,
michael@0: 			lsp,look->m,amp,info->ampdB,look->lsp_look);
michael@0:     return(1);
michael@0:   }
michael@0:   memset(out,0,sizeof(*out)*look->n);
michael@0:   return(0);
michael@0: }
michael@0: 
michael@0: /* export hooks */
michael@0: vorbis_func_floor floor0_exportbundle={
michael@0:   &floor0_unpack,&floor0_look,&floor0_free_info,
michael@0:   &floor0_free_look,&floor0_inverse1,&floor0_inverse2
michael@0: };
michael@0: 
michael@0: