ffmpeg/libavcodec/ra288.c

260 lines
6.3 KiB
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/*
* RealAudio 2.0 (28.8K)
* Copyright (c) 2003 the ffmpeg project
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "avcodec.h"
#include "ra288.h"
typedef struct {
float history[8];
float output[40];
float pr1[36];
float pr2[10];
int phase, phasep;
float st1a[111],st1b[37],st1[37];
float st2a[38],st2b[11],st2[11];
float sb[41];
float lhist[10];
} Real288_internal;
static int ra288_decode_init(AVCodecContext * avctx)
{
Real288_internal *glob=avctx->priv_data;
memset(glob,0,sizeof(Real288_internal));
return 0;
}
static void prodsum(float *tgt, float *src, int len, int n);
static void co(int n, int i, int j, float *in, float *out, float *st1, float *st2, const float *table);
static int pred(float *in, float *tgt, int n);
static void colmult(float *tgt, float *m1, const float *m2, int n);
/* initial decode */
static void unpack(unsigned short *tgt, const unsigned char *src, unsigned int len)
{
int x,y,z;
int n,temp;
int buffer[len];
for (x=0;x<len;tgt[x++]=0)
buffer[x]=9+(x&1);
for (x=y=z=0;x<len/*was 38*/;x++) {
n=buffer[y]-z;
temp=src[x];
if (n<8) temp&=255>>(8-n);
tgt[y]+=temp<<z;
if (n<=8) {
tgt[++y]+=src[x]>>n;
z=8-n;
} else z+=8;
}
}
static void update(Real288_internal *glob)
{
int x,y;
float buffer1[40],temp1[37];
float buffer2[8],temp2[11];
for (x=0,y=glob->phasep+5;x<40;buffer1[x++]=glob->output[(y++)%40]);
co(36,40,35,buffer1,temp1,glob->st1a,glob->st1b,table1);
if (pred(temp1,glob->st1,36))
colmult(glob->pr1,glob->st1,table1a,36);
for (x=0,y=glob->phase+1;x<8;buffer2[x++]=glob->history[(y++)%8]);
co(10,8,20,buffer2,temp2,glob->st2a,glob->st2b,table2);
if (pred(temp2,glob->st2,10))
colmult(glob->pr2,glob->st2,table2a,10);
}
/* Decode and produce output */
static void decode(Real288_internal *glob, unsigned int input)
{
unsigned int x,y;
float f;
double sum,sumsum;
float *p1,*p2;
float buffer[5];
const float *table;
for (x=36;x--;glob->sb[x+5]=glob->sb[x]);
for (x=5;x--;) {
p1=glob->sb+x;p2=glob->pr1;
for (sum=0,y=36;y--;sum-=(*(++p1))*(*(p2++)));
glob->sb[x]=sum;
}
f=amptable[input&7];
table=codetable+(input>>3)*5;
/* convert log and do rms */
for (sum=32,x=10;x--;sum-=glob->pr2[x]*glob->lhist[x]);
if (sum<0) sum=0; else if (sum>60) sum=60;
sumsum=exp(sum*0.1151292546497)*f; /* pow(10.0,sum/20)*f */
for (sum=0,x=5;x--;) { buffer[x]=table[x]*sumsum; sum+=buffer[x]*buffer[x]; }
if ((sum/=5)<1) sum=1;
/* shift and store */
for (x=10;--x;glob->lhist[x]=glob->lhist[x-1]);
*glob->lhist=glob->history[glob->phase]=10*log10(sum)-32;
for (x=1;x<5;x++) for (y=x;y--;buffer[x]-=glob->pr1[x-y-1]*buffer[y]);
/* output */
for (x=0;x<5;x++) {
f=glob->sb[4-x]+buffer[x];
if (f>4095) f=4095; else if (f<-4095) f=-4095;
glob->output[glob->phasep+x]=glob->sb[4-x]=f;
}
}
/* column multiply */
static void colmult(float *tgt, float *m1, const float *m2, int n)
{
while (n--)
*(tgt++)=(*(m1++))*(*(m2++));
}
static int pred(float *in, float *tgt, int n)
{
int x,y;
float *p1,*p2;
double f0,f1,f2;
float temp;
if (in[n]==0) return 0;
if ((f0=*in)<=0) return 0;
for (x=1;;x++) {
if (n<x) return 1;
p1=in+x;
p2=tgt;
f1=*(p1--);
for (y=x;--y;f1+=(*(p1--))*(*(p2++)));
p1=tgt+x-1;
p2=tgt;
*(p1--)=f2=-f1/f0;
for (y=x>>1;y--;) {
temp=*p2+*p1*f2;
*(p1--)+=*p2*f2;
*(p2++)=temp;
}
if ((f0+=f1*f2)<0) return 0;
}
}
static void co(int n, int i, int j, float *in, float *out, float *st1, float *st2, const float *table)
{
int a,b,c;
unsigned int x;
float *fp;
float buffer1[37];
float buffer2[37];
float work[111];
/* rotate and multiply */
c=(b=(a=n+i)+j)-i;
fp=st1+i;
for (x=0;x<b;x++) {
if (x==c) fp=in;
work[x]=*(table++)*(*(st1++)=*(fp++));
}
prodsum(buffer1,work+n,i,n);
prodsum(buffer2,work+a,j,n);
for (x=0;x<=n;x++) {
*st2=*st2*(0.5625)+buffer1[x];
out[x]=*(st2++)+buffer2[x];
}
*out*=1.00390625; /* to prevent clipping */
}
/* product sum (lsf) */
static void prodsum(float *tgt, float *src, int len, int n)
{
unsigned int x;
float *p1,*p2;
double sum;
while (n>=0)
{
p1=(p2=src)-n;
for (sum=0,x=len;x--;sum+=(*p1++)*(*p2++));
tgt[n--]=sum;
}
}
static void * decode_block(AVCodecContext * avctx, const unsigned char *in, signed short int *out,unsigned len)
{
int x,y;
Real288_internal *glob=avctx->priv_data;
unsigned short int buffer[len];
unpack(buffer,in,len);
for (x=0;x<32;x++)
{
glob->phasep=(glob->phase=x&7)*5;
decode(glob,buffer[x]);
for (y=0;y<5;*(out++)=8*glob->output[glob->phasep+(y++)]);
if (glob->phase==3) update(glob);
}
return out;
}
/* Decode a block (celp) */
static int ra288_decode_frame(AVCodecContext * avctx,
void *data, int *data_size,
const uint8_t * buf, int buf_size)
{
void *datao;
if (buf_size < avctx->block_align)
{
av_log(avctx, AV_LOG_ERROR, "ffra288: Error! Input buffer is too small [%d<%d]\n",buf_size,avctx->block_align);
return 0;
}
datao = data;
data = decode_block(avctx, buf, (signed short *)data, avctx->block_align);
*data_size = (char *)data - (char *)datao;
return avctx->block_align;
}
AVCodec ra_288_decoder =
{
"real_288",
CODEC_TYPE_AUDIO,
CODEC_ID_RA_288,
sizeof(Real288_internal),
ra288_decode_init,
NULL,
NULL,
ra288_decode_frame,
.long_name = NULL_IF_CONFIG_SMALL("RealAudio 2.0 (28.8K)"),
};