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#include <sys/types.h>
typedef unsigned short Uint16;
typedef unsigned int Uint32;
typedef struct {
unsigned int code,nbits;
} huff_t;
#include "table.h"
#define CODE1(a,b,c) (((a)<<10)|((b)&0x3ff)|((c)<<16))
/* run, level, bit */
#define CODE(a,b,c) CODE1(a,b,c+1),CODE1(a,-b,c+1)
#define CODE0(a,b,c) CODE1(a,b,c),CODE1(a,b,c)
#define CODE2(a,b,c) CODE1(a,b,c+1),CODE1(a,b,c+1)
#define RUNOF(a) ((a)>>10)
#define VALOF(a) ((short)((a)<<6)>>6)
#define BITOF(a) ((a)>>16)
#define EOB 0xfe00
#define ESCAPE_CODE CODE1(63,0,6)
#define EOB_CODE CODE1(63,512,2)
/*
DC code
Y U,V
0 100 00 0
1 00x 01x -1,1
2 01xx 10xx -3,-2,2,3
3 101xxx 110xxx -7..-4,4..7
4 110xxxx 1110 -15..-8,8..15
5 1110xxxxx 11110 -31..-16,16..31
6 11110xxxxxx 111110 -63..-32,32..63
7 111110 1111110 -127..-64,64..127
8 1111110 11111110 -255..-128,128..255
7+8 8+8
*/
/*
This table based on MPEG2DEC by MPEG Software Simulation Group
*/
/* Table B-14, DCT coefficients table zero,
* codes 0100 ... 1xxx (used for all other coefficients)
*/
static const Uint32 VLCtabnext[12*2] = {
CODE(0,2,4), CODE(2,1,4), CODE2(1,1,3), CODE2(1,-1,3),
CODE0(63,512,2), CODE0(63,512,2), CODE0(63,512,2), CODE0(63,512,2), /*EOB*/
CODE2(0,1,2), CODE2(0,1,2), CODE2(0,-1,2), CODE2(0,-1,2)
};
/* Table B-14, DCT coefficients table zero,
* codes 000001xx ... 00111xxx
*/
static const Uint32 VLCtab0[60*2] = {
CODE0(63,0,6), CODE0(63,0,6),CODE0(63,0,6), CODE0(63,0,6), /* ESCAPE */
CODE2(2,2,7), CODE2(2,-2,7), CODE2(9,1,7), CODE2(9,-1,7),
CODE2(0,4,7), CODE2(0,-4,7), CODE2(8,1,7), CODE2(8,-1,7),
CODE2(7,1,6), CODE2(7,1,6), CODE2(7,-1,6), CODE2(7,-1,6),
CODE2(6,1,6), CODE2(6,1,6), CODE2(6,-1,6), CODE2(6,-1,6),
CODE2(1,2,6), CODE2(1,2,6), CODE2(1,-2,6), CODE2(1,-2,6),
CODE2(5,1,6), CODE2(5,1,6), CODE2(5,-1,6), CODE2(5,-1,6),
CODE(13,1,8), CODE(0,6,8), CODE(12,1,8), CODE(11,1,8),
CODE(3,2,8), CODE(1,3,8), CODE(0,5,8), CODE(10,1,8),
CODE2(0,3,5), CODE2(0,3,5), CODE2(0,3,5), CODE2(0,3,5),
CODE2(0,-3,5), CODE2(0,-3,5), CODE2(0,-3,5), CODE2(0,-3,5),
CODE2(4,1,5), CODE2(4,1,5), CODE2(4,1,5), CODE2(4,1,5),
CODE2(4,-1,5), CODE2(4,-1,5), CODE2(4,-1,5), CODE2(4,-1,5),
CODE2(3,1,5), CODE2(3,1,5), CODE2(3,1,5), CODE2(3,1,5),
CODE2(3,-1,5), CODE2(3,-1,5), CODE2(3,-1,5), CODE2(3,-1,5)
};
/* Table B-14, DCT coefficients table zero,
* codes 0000001000 ... 0000001111
*/
static const Uint32 VLCtab1[8*2] = {
CODE(16,1,10), CODE(5,2,10), CODE(0,7,10), CODE(2,3,10),
CODE(1,4,10), CODE(15,1,10), CODE(14,1,10), CODE(4,2,10)
};
/* Table B-14/15, DCT coefficients table zero / one,
* codes 000000010000 ... 000000011111
*/
static const Uint32 VLCtab2[16*2] = {
CODE(0,11,12), CODE(8,2,12), CODE(4,3,12), CODE(0,10,12),
CODE(2,4,12), CODE(7,2,12), CODE(21,1,12), CODE(20,1,12),
CODE(0,9,12), CODE(19,1,12), CODE(18,1,12), CODE(1,5,12),
CODE(3,3,12), CODE(0,8,12), CODE(6,2,12), CODE(17,1,12)
};
/* Table B-14/15, DCT coefficients table zero / one,
* codes 0000000010000 ... 0000000011111
*/
static const Uint32 VLCtab3[16*2] = {
CODE(10,2,13), CODE(9,2,13), CODE(5,3,13), CODE(3,4,13),
CODE(2,5,13), CODE(1,7,13), CODE(1,6,13), CODE(0,15,13),
CODE(0,14,13), CODE(0,13,13), CODE(0,12,13), CODE(26,1,13),
CODE(25,1,13), CODE(24,1,13), CODE(23,1,13), CODE(22,1,13)
};
/* Table B-14/15, DCT coefficients table zero / one,
* codes 00000000010000 ... 00000000011111
*/
static const Uint32 VLCtab4[16*2] = {
CODE(0,31,14), CODE(0,30,14), CODE(0,29,14), CODE(0,28,14),
CODE(0,27,14), CODE(0,26,14), CODE(0,25,14), CODE(0,24,14),
CODE(0,23,14), CODE(0,22,14), CODE(0,21,14), CODE(0,20,14),
CODE(0,19,14), CODE(0,18,14), CODE(0,17,14), CODE(0,16,14)
};
/* Table B-14/15, DCT coefficients table zero / one,
* codes 000000000010000 ... 000000000011111
*/
static const Uint32 VLCtab5[16*2] = {
CODE(0,40,15), CODE(0,39,15), CODE(0,38,15), CODE(0,37,15),
CODE(0,36,15), CODE(0,35,15), CODE(0,34,15), CODE(0,33,15),
CODE(0,32,15), CODE(1,14,15), CODE(1,13,15), CODE(1,12,15),
CODE(1,11,15), CODE(1,10,15), CODE(1,9,15), CODE(1,8,15)
};
/* Table B-14/15, DCT coefficients table zero / one,
* codes 0000000000010000 ... 0000000000011111
*/
static const Uint32 VLCtab6[16*2] = {
CODE(1,18,16), CODE(1,17,16), CODE(1,16,16), CODE(1,15,16),
CODE(6,3,16), CODE(16,2,16), CODE(15,2,16), CODE(14,2,16),
CODE(13,2,16), CODE(12,2,16), CODE(11,2,16), CODE(31,1,16),
CODE(30,1,16), CODE(29,1,16), CODE(28,1,16), CODE(27,1,16)
};
/*
DC code
Y U,V
0 100 00 0
1 00x 01x -1,1
2 01xx 10xx -3,-2,2,3
3 101xxx 110xxx -7..-4,4..7
4 110xxxx 1110xxxx -15..-8,8..15
5 1110xxxxx 11110xxxxx -31..-16,16..31
6 11110xxxxxx 111110xxxxxx -63..-32,32..63
7 111110xxxxxxx 1111110xxxxxxx -127..-64,64..127
8 1111110xxxxxxxx 11111110xxxxxxxx -255..-128,128..255
*/
static const Uint32 DC_Ytab0[48] = {
CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),
CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),
CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),
CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),
CODE1(0,-3,4),CODE1(0,-3,4),CODE1(0,-3,4),CODE1(0,-3,4),
CODE1(0,-2,4),CODE1(0,-2,4),CODE1(0,-2,4),CODE1(0,-2,4),
CODE1(0,2,4),CODE1(0,2,4),CODE1(0,2,4),CODE1(0,2,4),
CODE1(0,3,4),CODE1(0,3,4),CODE1(0,3,4),CODE1(0,3,4),
CODE1(0,0,3),CODE1(0,0,3),CODE1(0,0,3),CODE1(0,0,3),
CODE1(0,0,3),CODE1(0,0,3),CODE1(0,0,3),CODE1(0,0,3),
CODE1(0,-7,6),CODE1(0,-6,6),CODE1(0,-5,6),CODE1(0,-4,6),
CODE1(0,4,6),CODE1(0,5,6),CODE1(0,6,6),CODE1(0,7,6),
};
static const Uint32 DC_UVtab0[56] = {
CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),
CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),
CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),
CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),CODE1(0,0,2),
CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),
CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),CODE1(0,-1,3),
CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),
CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),CODE1(0,1,3),
CODE1(0,-3,4),CODE1(0,-3,4),CODE1(0,-3,4),CODE1(0,-3,4),
CODE1(0,-2,4),CODE1(0,-2,4),CODE1(0,-2,4),CODE1(0,-2,4),
CODE1(0,2,4),CODE1(0,2,4),CODE1(0,2,4),CODE1(0,2,4),
CODE1(0,3,4),CODE1(0,3,4),CODE1(0,3,4),CODE1(0,3,4),
CODE1(0,-7,6),CODE1(0,-6,6),CODE1(0,-5,6),CODE1(0,-4,6),
CODE1(0,4,6),CODE1(0,5,6),CODE1(0,6,6),CODE1(0,7,6),
};
#define DCTSIZE2 64
/* decode one intra coded MPEG-1 block */
#define Show_Bits(N) (bitbuf>>(32-(N)))
/* 最小有効bit 17 bit*/
#define Flush_Buffer(N) {bitbuf <<=(N);incnt +=(N);while(incnt>=0) {bitbuf |= Get_Word()<<incnt;incnt-=16;}}
#define Init_Buffer() {bitbuf = (mdec_bs[0]<<16)|(mdec_bs[1]);mdec_bs+=2;incnt = -16;}
#define Get_Word() (*mdec_bs++)
#define Printf printf
int DecDCTvlc(Uint16 *mdec_bs,Uint16 *mdec_rl)
{
/* Uint16 *mdec_bs = mdecbs,*mdec_rl = mdecrl */
Uint16 *rl_end;
Uint32 bitbuf;
int incnt; /* 16-有効bit数 x86=char risc = long */
int q_code;
int type,n;
int last_dc[3];
/* BS_HDR Uint16 rlsize,magic,ver,q_scale */
/* printf("%04x,%04x,",mdec_bs[0],mdec_bs[1]); */
*(long*)mdec_rl=*(long*)mdec_bs;
mdec_rl+=2;
rl_end = mdec_rl+(int)mdec_bs[0]*2;
q_code = (mdec_bs[2]<<10); /* code = q */
type = mdec_bs[3];
mdec_bs+=4;
Init_Buffer();
n = 0;
last_dc[0]=last_dc[1]=last_dc[2] = 0;
while(mdec_rl<rl_end) {
Uint32 code2;
/* DC */
if (type==2) {
code2 = Show_Bits(10)|(10<<16); /* DC code */
} else {
code2 = Show_Bits(6);
if (n>=2) {
/* Y */
if (code2<48) {
code2 = DC_Ytab0[code2];
code2 = (code2&0xffff0000)|((last_dc[2]+=VALOF(code2)*4)&0x3ff);
} else {
int nbit,val;
int bit = 3;
while(Show_Bits(bit)&1) { bit++;}
bit++;
nbit = bit*2-1;
val = Show_Bits(nbit)&((1<<bit)-1);
if ((val&(1<<(bit-1)))==0)
val -= (1<<bit)-1;
val = (last_dc[2]+=val*4);
code2 = (nbit<<16) | (val&0x3ff);
}
/* printf("%d ",last_dc[2]); */
} else {
/* U,V */
if (code2<56) {
code2 = DC_UVtab0[code2];
code2 = (code2&0xffff0000)|((last_dc[n]+=VALOF(code2)*4)&0x3ff);
} else {
int nbit,val;
int bit = 4;
while(Show_Bits(bit)&1) { bit++;}
nbit = bit*2;
val = Show_Bits(nbit)&((1<<bit)-1);
if ((val&(1<<(bit-1)))==0)
val -= (1<<bit)-1;
val = (last_dc[n]+=val*4);
code2 = (nbit<<16) | (val&0x3ff);
}
/* printf("%d ",last_dc[n]); */
}
if (++n==6) n=0;
}
/* printf("%d ",VALOF(code2)); */
code2 |= q_code;
/* AC */
while(mdec_rl<rl_end){
/* Uint32 code; */
#define code code2
#define SBIT 17
*mdec_rl++=code2;
Flush_Buffer(BITOF(code2));
code = Show_Bits(SBIT);
if (code>=1<<(SBIT- 2)) {
code2 = VLCtabnext[(code>>12)-8];
if (code2==EOB_CODE) break;
}
else if (code>=1<<(SBIT- 6)) {
code2 = VLCtab0[(code>>8)-8];
if (code2==ESCAPE_CODE) {
Flush_Buffer(6); /* ESCAPE len */
code2 = Show_Bits(16)| (16<<16);
}
}
else if (code>=1<<(SBIT- 7)) code2 = VLCtab1[(code>>6)-16];
else if (code>=1<<(SBIT- 8)) code2 = VLCtab2[(code>>4)-32];
else if (code>=1<<(SBIT- 9)) code2 = VLCtab3[(code>>3)-32];
else if (code>=1<<(SBIT-10)) code2 = VLCtab4[(code>>2)-32];
else if (code>=1<<(SBIT-11)) code2 = VLCtab5[(code>>1)-32];
else if (code>=1<<(SBIT-12)) code2 = VLCtab6[(code>>0)-32];
else {
do {
*mdec_rl++=EOB;
} while(mdec_rl<rl_end);
return 0;
}
}
*mdec_rl++=code2; /* EOB code */
Flush_Buffer(2); /* EOB bitlen */
}
return 0;
}
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