extern/ffmpeg/libavcodec/ra288.c

   1 /*
   2  * RealAudio 2.0 (28.8K)
   3  * Copyright (c) 2003 the ffmpeg project
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18  */
  19
  20 #include "avcodec.h"
  21 #include "ra288.h"
  22
  23 typedef struct {
  24         float   history[8];
  25         float   output[40];
  26         float   pr1[36];
  27         float   pr2[10];
  28         int     phase, phasep;
  29
  30         float   st1a[111],st1b[37],st1[37];
  31         float   st2a[38],st2b[11],st2[11];
  32         float   sb[41];
  33         float   lhist[10];
  34 } Real288_internal;
  35
  36 static int ra288_decode_init(AVCodecContext * avctx)
  37 {
  38         Real288_internal *glob=avctx->priv_data;
  39         memset(glob,0,sizeof(Real288_internal));
  40         return 0;
  41 }
  42
  43 static void prodsum(float *tgt, float *src, int len, int n);
  44 static void co(int n, int i, int j, float *in, float *out, float *st1, float *st2, const float *table);
  45 static int pred(float *in, float *tgt, int n);
  46 static void colmult(float *tgt, float *m1, const float *m2, int n);
  47
  48
  49 /* initial decode */
  50 static void unpack(unsigned short *tgt, unsigned char *src, unsigned int len)
  51 {
  52   int x,y,z;
  53   int n,temp;
  54   int buffer[len];
  55
  56   for (x=0;x<len;tgt[x++]=0)
  57     buffer[x]=9+(x&1);
  58
  59   for (x=y=z=0;x<len/*was 38*/;x++) {
  60     n=buffer[y]-z;
  61     temp=src[x];
  62     if (n<8) temp&=255>>(8-n);
  63     tgt[y]+=temp<<z;
  64     if (n<=8) {
  65       tgt[++y]+=src[x]>>n;
  66       z=8-n;
  67     } else z+=8;
  68   }
  69 }
  70
  71 static void update(Real288_internal *glob)
  72 {
  73   int x,y;
  74   float buffer1[40],temp1[37];
  75   float buffer2[8],temp2[11];
  76
  77   for (x=0,y=glob->phasep+5;x<40;buffer1[x++]=glob->output[(y++)%40]);
  78   co(36,40,35,buffer1,temp1,glob->st1a,glob->st1b,table1);
  79   if (pred(temp1,glob->st1,36))
  80     colmult(glob->pr1,glob->st1,table1a,36);
  81
  82   for (x=0,y=glob->phase+1;x<8;buffer2[x++]=glob->history[(y++)%8]);
  83   co(10,8,20,buffer2,temp2,glob->st2a,glob->st2b,table2);
  84   if (pred(temp2,glob->st2,10))
  85     colmult(glob->pr2,glob->st2,table2a,10);
  86 }
  87
  88 /* Decode and produce output */
  89 static void decode(Real288_internal *glob, unsigned int input)
  90 {
  91   unsigned int x,y;
  92   float f;
  93   double sum,sumsum;
  94   float *p1,*p2;
  95   float buffer[5];
  96   const float *table;
  97
  98   for (x=36;x--;glob->sb[x+5]=glob->sb[x]);
  99   for (x=5;x--;) {
 100     p1=glob->sb+x;p2=glob->pr1;
 101     for (sum=0,y=36;y--;sum-=(*(++p1))*(*(p2++)));
 102     glob->sb[x]=sum;
 103   }
 104
 105   f=amptable[input&7];
 106   table=codetable+(input>>3)*5;
 107
 108   /* convert log and do rms */
 109   for (sum=32,x=10;x--;sum-=glob->pr2[x]*glob->lhist[x]);
 110   if (sum<0) sum=0; else if (sum>60) sum=60;
 111
 112   sumsum=exp(sum*0.1151292546497)*f;    /* pow(10.0,sum/20)*f */
 113   for (sum=0,x=5;x--;) { buffer[x]=table[x]*sumsum; sum+=buffer[x]*buffer[x]; }
 114   if ((sum/=5)<1) sum=1;
 115
 116   /* shift and store */
 117   for (x=10;--x;glob->lhist[x]=glob->lhist[x-1]);
 118   *glob->lhist=glob->history[glob->phase]=10*log10(sum)-32;
 119
 120   for (x=1;x<5;x++) for (y=x;y--;buffer[x]-=glob->pr1[x-y-1]*buffer[y]);
 121
 122   /* output */
 123   for (x=0;x<5;x++) {
 124     f=glob->sb[4-x]+buffer[x];
 125     if (f>4095) f=4095; else if (f<-4095) f=-4095;
 126     glob->output[glob->phasep+x]=glob->sb[4-x]=f;
 127   }
 128 }
 129
 130 /* column multiply */
 131 static void colmult(float *tgt, float *m1, const float *m2, int n)
 132 {
 133   while (n--)
 134     *(tgt++)=(*(m1++))*(*(m2++));
 135 }
 136
 137 static int pred(float *in, float *tgt, int n)
 138 {
 139   int x,y;
 140   float *p1,*p2;
 141   double f0,f1,f2;
 142   float temp;
 143
 144   if (in[n]==0) return 0;
 145   if ((f0=*in)<=0) return 0;
 146
 147   for (x=1;;x++) {
 148     if (n<x) return 1;
 149
 150     p1=in+x;
 151     p2=tgt;
 152     f1=*(p1--);
 153     for (y=x;--y;f1+=(*(p1--))*(*(p2++)));
 154
 155     p1=tgt+x-1;
 156     p2=tgt;
 157     *(p1--)=f2=-f1/f0;
 158     for (y=x>>1;y--;) {
 159       temp=*p2+*p1*f2;
 160       *(p1--)+=*p2*f2;
 161       *(p2++)=temp;
 162     }
 163     if ((f0+=f1*f2)<0) return 0;
 164   }
 165 }
 166
 167 static void co(int n, int i, int j, float *in, float *out, float *st1, float *st2, const float *table)
 168 {
 169   int a,b,c;
 170   unsigned int x;
 171   float *fp;
 172   float buffer1[37];
 173   float buffer2[37];
 174   float work[111];
 175
 176   /* rotate and multiply */
 177   c=(b=(a=n+i)+j)-i;
 178   fp=st1+i;
 179   for (x=0;x<b;x++) {
 180     if (x==c) fp=in;
 181     work[x]=*(table++)*(*(st1++)=*(fp++));
 182   }
 183
 184   prodsum(buffer1,work+n,i,n);
 185   prodsum(buffer2,work+a,j,n);
 186
 187   for (x=0;x<=n;x++) {
 188     *st2=*st2*(0.5625)+buffer1[x];
 189     out[x]=*(st2++)+buffer2[x];
 190   }
 191   *out*=1.00390625; /* to prevent clipping */
 192 }
 193
 194 /* product sum (lsf) */
 195 static void prodsum(float *tgt, float *src, int len, int n)
 196 {
 197   unsigned int x;
 198   float *p1,*p2;
 199   double sum;
 200
 201   while (n>=0)
 202   {
 203     p1=(p2=src)-n;
 204     for (sum=0,x=len;x--;sum+=(*p1++)*(*p2++));
 205     tgt[n--]=sum;
 206   }
 207 }
 208
 209 static void * decode_block(AVCodecContext * avctx, unsigned char *in, signed short int *out,unsigned len)
 210 {
 211   int x,y;
 212   Real288_internal *glob=avctx->priv_data;
 213   unsigned short int buffer[len];
 214
 215   unpack(buffer,in,len);
 216   for (x=0;x<32;x++)
 217   {
 218     glob->phasep=(glob->phase=x&7)*5;
 219     decode(glob,buffer[x]);
 220     for (y=0;y<5;*(out++)=8*glob->output[glob->phasep+(y++)]);
 221     if (glob->phase==3) update(glob);
 222   }
 223   return out;
 224 }
 225
 226 /* Decode a block (celp) */
 227 static int ra288_decode_frame(AVCodecContext * avctx,
 228             void *data, int *data_size,
 229             uint8_t * buf, int buf_size)
 230 {
 231     void *datao;
 232
 233     if (buf_size < avctx->block_align)
 234     {
 235         av_log(avctx, AV_LOG_ERROR, "ffra288: Error! Input buffer is too small [%d<%d]\n",buf_size,avctx->block_align);
 236         return 0;
 237     }
 238
 239     datao = data;
 240     data = decode_block(avctx, buf, (signed short *)data, avctx->block_align);
 241
 242     *data_size = (char *)data - (char *)datao;
 243     return avctx->block_align;
 244 }
 245
 246 AVCodec ra_288_decoder =
 247 {
 248     "real_288",
 249     CODEC_TYPE_AUDIO,
 250     CODEC_ID_RA_288,
 251     sizeof(Real288_internal),
 252     ra288_decode_init,
 253     NULL,
 254     NULL,
 255     ra288_decode_frame,
 256 };