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decoders.c
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C/C++ Source or Header
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1994-04-22
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14KB
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390 lines
/*
* decoders.c
*
* This file contains all the routines for Huffman decoding required in MPEG
*
*/
#include <stdio.h>
#include "decoders.h"
#include "util.h"
#include "video.h"
#include "proto.h"
/* Decoding table for macroblock_address_increment */
mb_addr_inc_entry mb_addr_inc[2048];
/* Decoding table for macroblock_type in intra-coded pictures */
mb_type_entry mb_type_I[4] = { {ERROR,0}, {17,2}, {1,1}, {1,1} };
/* Decoding table for macroblock_type in predictive-coded pictures */
mb_type_entry mb_type_P[64];
/* Decoding table for macroblock_type in bidirectionally-coded pictures */
mb_type_entry mb_type_B[64];
/* Decoding table for motion vectors */
motion_vectors_entry motion_vectors[2048];
/* DCT coeff tables. */
unsigned short int dct_coeff_tbl_0[256] = {
0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff,
0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff, 0xffff,
0x052f, 0x051f, 0x050f, 0x04ff, 0x183f, 0x402f, 0x3c2f, 0x382f,
0x342f, 0x302f, 0x2c2f, 0x7c1f, 0x781f, 0x741f, 0x701f, 0x6c1f,
0x028e, 0x028e, 0x027e, 0x027e, 0x026e, 0x026e, 0x025e, 0x025e,
0x024e, 0x024e, 0x023e, 0x023e, 0x022e, 0x022e, 0x021e, 0x021e,
0x020e, 0x020e, 0x04ee, 0x04ee, 0x04de, 0x04de, 0x04ce, 0x04ce,
0x04be, 0x04be, 0x04ae, 0x04ae, 0x049e, 0x049e, 0x048e, 0x048e,
0x01fd, 0x01fd, 0x01fd, 0x01fd, 0x01ed, 0x01ed, 0x01ed, 0x01ed,
0x01dd, 0x01dd, 0x01dd, 0x01dd, 0x01cd, 0x01cd, 0x01cd, 0x01cd,
0x01bd, 0x01bd, 0x01bd, 0x01bd, 0x01ad, 0x01ad, 0x01ad, 0x01ad,
0x019d, 0x019d, 0x019d, 0x019d, 0x018d, 0x018d, 0x018d, 0x018d,
0x017d, 0x017d, 0x017d, 0x017d, 0x016d, 0x016d, 0x016d, 0x016d,
0x015d, 0x015d, 0x015d, 0x015d, 0x014d, 0x014d, 0x014d, 0x014d,
0x013d, 0x013d, 0x013d, 0x013d, 0x012d, 0x012d, 0x012d, 0x012d,
0x011d, 0x011d, 0x011d, 0x011d, 0x010d, 0x010d, 0x010d, 0x010d,
0x282c, 0x282c, 0x282c, 0x282c, 0x282c, 0x282c, 0x282c, 0x282c,
0x242c, 0x242c, 0x242c, 0x242c, 0x242c, 0x242c, 0x242c, 0x242c,
0x143c, 0x143c, 0x143c, 0x143c, 0x143c, 0x143c, 0x143c, 0x143c,
0x0c4c, 0x0c4c, 0x0c4c, 0x0c4c, 0x0c4c, 0x0c4c, 0x0c4c, 0x0c4c,
0x085c, 0x085c, 0x085c, 0x085c, 0x085c, 0x085c, 0x085c, 0x085c,
0x047c, 0x047c, 0x047c, 0x047c, 0x047c, 0x047c, 0x047c, 0x047c,
0x046c, 0x046c, 0x046c, 0x046c, 0x046c, 0x046c, 0x046c, 0x046c,
0x00fc, 0x00fc, 0x00fc, 0x00fc, 0x00fc, 0x00fc, 0x00fc, 0x00fc,
0x00ec, 0x00ec, 0x00ec, 0x00ec, 0x00ec, 0x00ec, 0x00ec, 0x00ec,
0x00dc, 0x00dc, 0x00dc, 0x00dc, 0x00dc, 0x00dc, 0x00dc, 0x00dc,
0x00cc, 0x00cc, 0x00cc, 0x00cc, 0x00cc, 0x00cc, 0x00cc, 0x00cc,
0x681c, 0x681c, 0x681c, 0x681c, 0x681c, 0x681c, 0x681c, 0x681c,
0x641c, 0x641c, 0x641c, 0x641c, 0x641c, 0x641c, 0x641c, 0x641c,
0x601c, 0x601c, 0x601c, 0x601c, 0x601c, 0x601c, 0x601c, 0x601c,
0x5c1c, 0x5c1c, 0x5c1c, 0x5c1c, 0x5c1c, 0x5c1c, 0x5c1c, 0x5c1c,
0x581c, 0x581c, 0x581c, 0x581c, 0x581c, 0x581c, 0x581c, 0x581c
};
unsigned short int dct_coeff_tbl_1[16] = {
0x00bb, 0x202b, 0x103b, 0x00ab, 0x084b, 0x1c2b, 0x541b, 0x501b,
0x009b, 0x4c1b, 0x481b, 0x045b, 0x0c3b, 0x008b, 0x182b, 0x441b
};
unsigned short int dct_coeff_tbl_2[4] = {
0x4019, 0x1429, 0x0079, 0x0839
};
unsigned short int dct_coeff_tbl_3[4] = {
0x0449, 0x3c19, 0x3819, 0x1029
};
unsigned short int dct_coeff_next[256] = {
0xffff, 0xffff, 0xffff, 0xffff, 0xf7d5, 0xf7d5, 0xf7d5, 0xf7d5,
0x0826, 0x0826, 0x2416, 0x2416, 0x0046, 0x0046, 0x2016, 0x2016,
0x1c15, 0x1c15, 0x1c15, 0x1c15, 0x1815, 0x1815, 0x1815, 0x1815,
0x0425, 0x0425, 0x0425, 0x0425, 0x1415, 0x1415, 0x1415, 0x1415,
0x3417, 0x0067, 0x3017, 0x2c17, 0x0c27, 0x0437, 0x0057, 0x2817,
0x0034, 0x0034, 0x0034, 0x0034, 0x0034, 0x0034, 0x0034, 0x0034,
0x1014, 0x1014, 0x1014, 0x1014, 0x1014, 0x1014, 0x1014, 0x1014,
0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14,
0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023,
0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023,
0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813,
0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1, 0xfbe1,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011,
0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011, 0x0011
};
unsigned short int dct_coeff_first[256] = {
0xffff, 0xffff, 0xffff, 0xffff, 0xf7d5, 0xf7d5, 0xf7d5, 0xf7d5,
0x0826, 0x0826, 0x2416, 0x2416, 0x0046, 0x0046, 0x2016, 0x2016,
0x1c15, 0x1c15, 0x1c15, 0x1c15, 0x1815, 0x1815, 0x1815, 0x1815,
0x0425, 0x0425, 0x0425, 0x0425, 0x1415, 0x1415, 0x1415, 0x1415,
0x3417, 0x0067, 0x3017, 0x2c17, 0x0c27, 0x0437, 0x0057, 0x2817,
0x0034, 0x0034, 0x0034, 0x0034, 0x0034, 0x0034, 0x0034, 0x0034,
0x1014, 0x1014, 0x1014, 0x1014, 0x1014, 0x1014, 0x1014, 0x1014,
0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14, 0x0c14,
0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023,
0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023, 0x0023,
0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813,
0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813, 0x0813,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412, 0x0412,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010,
0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010, 0x0010
};
/*
*--------------------------------------------------------------
*
* init_mb_addr_inc --
*
* Initialize the VLC decoding table for macro_block_address_increment
*
* Results:
* The decoding table for macro_block_address_increment will
* be filled; illegal values will be filled as ERROR.
*
* Side effects:
* The global array mb_addr_inc will be filled.
*
*--------------------------------------------------------------
*/
/* Macro for filling up the decoding table for mb_addr_inc */
#define ASSIGN1(start, end, step, val, num) \
for (i = start; i < end; i+= step) { \
for (j = 0; j < step; j++) { \
mb_addr_inc[i+j].value = val; \
mb_addr_inc[i+j].num_bits = num; \
} \
val--; \
}
static void init_mb_addr_inc(void)
{
int i, j, val;
for (i = 0; i < 8; i++) {
mb_addr_inc[i].value = ERROR;
mb_addr_inc[i].num_bits = 0;
}
mb_addr_inc[8].value = MACRO_BLOCK_ESCAPE;
mb_addr_inc[8].num_bits = 11;
for (i = 9; i < 15; i++) {
mb_addr_inc[i].value = ERROR;
mb_addr_inc[i].num_bits = 0;
}
mb_addr_inc[15].value = MACRO_BLOCK_STUFFING;
mb_addr_inc[15].num_bits = 11;
for (i = 16; i < 24; i++) {
mb_addr_inc[i].value = ERROR;
mb_addr_inc[i].num_bits = 0;
}
val = 33;
ASSIGN1(24, 36, 1, val, 11);
ASSIGN1(36, 48, 2, val, 10);
ASSIGN1(48, 96, 8, val, 8);
ASSIGN1(96, 128, 16, val, 7);
ASSIGN1(128, 256, 64, val, 5);
ASSIGN1(256, 512, 128, val, 4);
ASSIGN1(512, 1024, 256, val, 3);
ASSIGN1(1024, 2048, 1024, val, 1);
}
/*
*--------------------------------------------------------------
*
* init_mb_type_P --
*
* Initialize the VLC decoding table for macro_block_type in
* predictive-coded pictures.
*
* Results:
* The decoding table for macro_block_type in predictive-coded
* pictures will be filled; illegal values will be filled as ERROR.
*
* Side effects:
* The global array mb_type_P will be filled.
*
*--------------------------------------------------------------
*/
/* Macro for filling up the decoding table for mb_type */
#define ASSIGN2(start, end, quant, motion_forward, motion_backward, pattern, intra, num, mb_type) \
for (i = start; i < end; i ++) { \
mb_type[i].data = (quant<<4)|(motion_forward<<3)|(motion_backward<<2)|(pattern<<1)|(intra); \
mb_type[i].num_bits = num; \
}
static void init_mb_type_P(void)
{
int i;
mb_type_P[0].data = ERROR;
mb_type_P[0].num_bits = 0;
ASSIGN2(1, 2, 1, 0, 0, 0, 1, 6, mb_type_P)
ASSIGN2(2, 4, 1, 0, 0, 1, 0, 5, mb_type_P)
ASSIGN2(4, 6, 1, 1, 0, 1, 0, 5, mb_type_P);
ASSIGN2(6, 8, 0, 0, 0, 0, 1, 5, mb_type_P);
ASSIGN2(8, 16, 0, 1, 0, 0, 0, 3, mb_type_P);
ASSIGN2(16, 32, 0, 0, 0, 1, 0, 2, mb_type_P);
ASSIGN2(32, 64, 0, 1, 0, 1, 0, 1, mb_type_P);
}
/*
*--------------------------------------------------------------
*
* init_mb_type_B --
*
* Initialize the VLC decoding table for macro_block_type in
* bidirectionally-coded pictures.
*
* Results:
* The decoding table for macro_block_type in bidirectionally-coded
* pictures will be filled; illegal values will be filled as ERROR.
*
* Side effects:
* The global array mb_type_B will be filled.
*
*--------------------------------------------------------------
*/
static void init_mb_type_B(void)
{
int i;
mb_type_B[0].data = ERROR;
mb_type_B[0].num_bits = 0;
ASSIGN2(1, 2, 1, 0, 0, 0, 1, 6, mb_type_B);
ASSIGN2(2, 3, 1, 0, 1, 1, 0, 6, mb_type_B);
ASSIGN2(3, 4, 1, 1, 0, 1, 0, 6, mb_type_B);
ASSIGN2(4, 6, 1, 1, 1, 1, 0, 5, mb_type_B);
ASSIGN2(6, 8, 0, 0, 0, 0, 1, 5, mb_type_B);
ASSIGN2(8, 12, 0, 1, 0, 0, 0, 4, mb_type_B);
ASSIGN2(12, 16, 0, 1, 0, 1, 0, 4, mb_type_B);
ASSIGN2(16, 24, 0, 0, 1, 0, 0, 3, mb_type_B);
ASSIGN2(24, 32, 0, 0, 1, 1, 0, 3, mb_type_B);
ASSIGN2(32, 48, 0, 1, 1, 0, 0, 2, mb_type_B);
ASSIGN2(48, 64, 0, 1, 1, 1, 0, 2, mb_type_B);
}
/*
*--------------------------------------------------------------
*
* init_motion_vectors --
*
* Initialize the VLC decoding table for the various motion
* vectors, including motion_horizontal_forward_code,
* motion_vertical_forward_code, motion_horizontal_backward_code,
* and motion_vertical_backward_code.
*
* Results:
* The decoding table for the motion vectors will be filled;
* illegal values will be filled as ERROR.
*
* Side effects:
* The global array motion_vector will be filled.
*
*--------------------------------------------------------------
*/
/* Macro for filling up the decoding tables for motion_vectors */
#define ASSIGN3(start, end, step, val, num) \
for (i = start; i < end; i+= step) { \
for (j = 0; j < step / 2; j++) { \
motion_vectors[i+j].code = val; \
motion_vectors[i+j].num_bits = num; \
} \
for (j = step / 2; j < step; j++) { \
motion_vectors[i+j].code = -val; \
motion_vectors[i+j].num_bits = num; \
} \
val--; \
}
static void init_motion_vectors(void)
{
int i, j, val = 16;
for (i = 0; i < 24; i++) {
motion_vectors[i].code = ERROR;
motion_vectors[i].num_bits = 0;
}
ASSIGN3(24, 36, 2, val, 11);
ASSIGN3(36, 48, 4, val, 10);
ASSIGN3(48, 96, 16, val, 8);
ASSIGN3(96, 128, 32, val, 7);
ASSIGN3(128, 256, 128, val, 5);
ASSIGN3(256, 512, 256, val, 4);
ASSIGN3(512, 1024, 512, val, 3);
ASSIGN3(1024, 2048, 1024, val, 1);
}
/*
*--------------------------------------------------------------
*
* init_tables --
*
* Initialize all the tables for VLC decoding; this must be
* called when the system is set up before any decoding can
* take place.
*
* Results:
* All the decoding tables will be filled accordingly.
*
* Side effects:
* The corresponding global array for each decoding table
* will be filled.
*
*--------------------------------------------------------------
*/
void init_tables(void)
{
// extern void init_pre_idct();
init_mb_addr_inc();
init_mb_type_P();
init_mb_type_B();
init_motion_vectors();
// init_pre_idct();
#ifdef ANALYSIS
{
init_stats();
}
#endif
}