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FFmpeg/libavcodec/mpeg12.c
BERO 05858889b2 decode motion & modulo optimize patch by (BERO <bero at geocities dot co dot jp>) 
Originally committed as revision 1872 to svn://svn.ffmpeg.org/ffmpeg/trunk
2003-05-14 01:08:02 +00:00

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/*
* MPEG1 codec / MPEG2 decoder
* Copyright (c) 2000,2001 Fabrice Bellard.
*
* This library 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 of the License, or (at your option) any later version.
*
* This library 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 this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
/**
* @file mpeg12.c
* MPEG1 codec / MPEG2 decoder.
*/
//#define DEBUG
#include "avcodec.h"
#include "dsputil.h"
#include "mpegvideo.h"
#include "mpeg12data.h"
/* Start codes. */
#define SEQ_END_CODE 0x000001b7
#define SEQ_START_CODE 0x000001b3
#define GOP_START_CODE 0x000001b8
#define PICTURE_START_CODE 0x00000100
#define SLICE_MIN_START_CODE 0x00000101
#define SLICE_MAX_START_CODE 0x000001af
#define EXT_START_CODE 0x000001b5
#define USER_START_CODE 0x000001b2
#define DC_VLC_BITS 9
#define MV_VLC_BITS 9
#define MBINCR_VLC_BITS 9
#define MB_PAT_VLC_BITS 9
#define MB_PTYPE_VLC_BITS 6
#define MB_BTYPE_VLC_BITS 6
#define TEX_VLC_BITS 9
static void mpeg1_encode_block(MpegEncContext *s,
DCTELEM *block,
int component);
static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code); // RAL: f_code parameter added
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
static inline int mpeg1_decode_block_inter(MpegEncContext *s,
DCTELEM *block,
int n);
static inline int mpeg1_decode_block_intra(MpegEncContext *s,
DCTELEM *block,
int n);
static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
DCTELEM *block,
int n);
static inline int mpeg2_decode_block_intra(MpegEncContext *s,
DCTELEM *block,
int n);
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
#ifdef CONFIG_ENCODERS
static uint8_t (*mv_penalty)[MAX_MV*2+1]= NULL;
static uint8_t fcode_tab[MAX_MV*2+1];
static uint32_t uni_mpeg1_ac_vlc_bits[64*64*2];
static uint8_t uni_mpeg1_ac_vlc_len [64*64*2];
#endif
static void init_2d_vlc_rl(RLTable *rl)
{
int i;
init_vlc(&rl->vlc, TEX_VLC_BITS, rl->n + 2,
&rl->table_vlc[0][1], 4, 2,
&rl->table_vlc[0][0], 4, 2);
rl->rl_vlc[0]= av_malloc(rl->vlc.table_size*sizeof(RL_VLC_ELEM));
for(i=0; i<rl->vlc.table_size; i++){
int code= rl->vlc.table[i][0];
int len = rl->vlc.table[i][1];
int level, run;
if(len==0){ // illegal code
run= 65;
level= MAX_LEVEL;
}else if(len<0){ //more bits needed
run= 0;
level= code;
}else{
if(code==rl->n){ //esc
run= 65;
level= 0;
}else if(code==rl->n+1){ //eob
run= 0;
level= 127;
}else{
run= rl->table_run [code] + 1;
level= rl->table_level[code];
}
}
rl->rl_vlc[0][i].len= len;
rl->rl_vlc[0][i].level= level;
rl->rl_vlc[0][i].run= run;
}
}
static void init_uni_ac_vlc(RLTable *rl, uint32_t *uni_ac_vlc_bits, uint8_t *uni_ac_vlc_len){
int i;
for(i=0; i<128; i++){
int level= i-64;
int run;
for(run=0; run<64; run++){
int len, bits, code;
int alevel= ABS(level);
int sign= (level>>31)&1;
if (alevel > rl->max_level[0][run])
code= 111; /*rl->n*/
else
code= rl->index_run[0][run] + alevel - 1;
if (code < 111 /* rl->n */) {
/* store the vlc & sign at once */
len= mpeg1_vlc[code][1]+1;
bits= (mpeg1_vlc[code][0]<<1) + sign;
} else {
len= mpeg1_vlc[111/*rl->n*/][1]+6;
bits= mpeg1_vlc[111/*rl->n*/][0]<<6;
bits|= run;
if (alevel < 128) {
bits<<=8; len+=8;
bits|= level & 0xff;
} else {
bits<<=16; len+=16;
bits|= level & 0xff;
if (level < 0) {
bits|= 0x8001 + level + 255;
} else {
bits|= level & 0xffff;
}
}
}
uni_ac_vlc_bits[UNI_AC_ENC_INDEX(run, i)]= bits;
uni_ac_vlc_len [UNI_AC_ENC_INDEX(run, i)]= len;
}
}
}
static void put_header(MpegEncContext *s, int header)
{
align_put_bits(&s->pb);
put_bits(&s->pb, 16, header>>16);
put_bits(&s->pb, 16, header&0xFFFF);
}
/* put sequence header if needed */
static void mpeg1_encode_sequence_header(MpegEncContext *s)
{
unsigned int vbv_buffer_size;
unsigned int fps, v;
int n, i;
uint64_t time_code;
float best_aspect_error= 1E10;
float aspect_ratio= s->avctx->aspect_ratio;
if(aspect_ratio==0.0) aspect_ratio= s->width / (float)s->height; //pixel aspect 1:1 (VGA)
if (s->current_picture.key_frame) {
/* mpeg1 header repeated every gop */
put_header(s, SEQ_START_CODE);
/* search closest frame rate */
{
int i, dmin, d;
s->frame_rate_index = 0;
dmin = 0x7fffffff;
for(i=1;i<14;i++) {
if(s->avctx->strict_std_compliance >= 0 && i>=9) break;
d = abs(MPEG1_FRAME_RATE_BASE*(int64_t)s->avctx->frame_rate/s->avctx->frame_rate_base - frame_rate_tab[i]);
if (d < dmin) {
dmin = d;
s->frame_rate_index = i;
}
}
}
put_bits(&s->pb, 12, s->width);
put_bits(&s->pb, 12, s->height);
for(i=1; i<15; i++){
float error= mpeg1_aspect[i] - s->width/(s->height*aspect_ratio);
error= ABS(error);
if(error < best_aspect_error){
best_aspect_error= error;
s->aspect_ratio_info= i;
}
}
put_bits(&s->pb, 4, s->aspect_ratio_info);
put_bits(&s->pb, 4, s->frame_rate_index);
v = (s->bit_rate + 399) / 400;
if (v > 0x3ffff)
v = 0x3ffff;
put_bits(&s->pb, 18, v);
put_bits(&s->pb, 1, 1); /* marker */
if(s->avctx->rc_buffer_size)
vbv_buffer_size = s->avctx->rc_buffer_size;
else
/* VBV calculation: Scaled so that a VCD has the proper VBV size of 40 kilobytes */
vbv_buffer_size = (( 20 * s->bit_rate) / (1151929 / 2)) * 8 * 1024;
put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
put_bits(&s->pb, 1, 1); /* constrained parameter flag */
put_bits(&s->pb, 1, 0); /* no custom intra matrix */
put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
put_header(s, GOP_START_CODE);
put_bits(&s->pb, 1, 0); /* do drop frame */
/* time code : we must convert from the real frame rate to a
fake mpeg frame rate in case of low frame rate */
fps = frame_rate_tab[s->frame_rate_index];
time_code = (int64_t)s->fake_picture_number * MPEG1_FRAME_RATE_BASE;
s->gop_picture_number = s->fake_picture_number;
put_bits(&s->pb, 5, (uint32_t)((time_code / (fps * 3600)) % 24));
put_bits(&s->pb, 6, (uint32_t)((time_code / (fps * 60)) % 60));
put_bits(&s->pb, 1, 1);
put_bits(&s->pb, 6, (uint32_t)((time_code / fps) % 60));
put_bits(&s->pb, 6, (uint32_t)((time_code % fps) / MPEG1_FRAME_RATE_BASE));
put_bits(&s->pb, 1, 1); /* closed gop */
put_bits(&s->pb, 1, 0); /* broken link */
}
if (s->avctx->frame_rate < (24 * s->avctx->frame_rate_base) && s->picture_number > 0) {
/* insert empty P pictures to slow down to the desired
frame rate. Each fake pictures takes about 20 bytes */
fps = frame_rate_tab[s->frame_rate_index];
n = av_rescale((int64_t)s->picture_number * s->avctx->frame_rate_base, fps, s->avctx->frame_rate) / MPEG1_FRAME_RATE_BASE - 1;
while (s->fake_picture_number < n) {
mpeg1_skip_picture(s, s->fake_picture_number -
s->gop_picture_number);
s->fake_picture_number++;
}
}
}
static inline void encode_mb_skip_run(MpegEncContext *s, int run){
while (run >= 33) {
put_bits(&s->pb, 11, 0x008);
run -= 33;
}
put_bits(&s->pb, mbAddrIncrTable[run][1],
mbAddrIncrTable[run][0]);
}
/* insert a fake P picture */
static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
{
/* mpeg1 picture header */
put_header(s, PICTURE_START_CODE);
/* temporal reference */
put_bits(&s->pb, 10, pict_num & 0x3ff);
put_bits(&s->pb, 3, P_TYPE);
put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
put_bits(&s->pb, 1, 1); /* integer coordinates */
put_bits(&s->pb, 3, 1); /* forward_f_code */
put_bits(&s->pb, 1, 0); /* extra bit picture */
/* only one slice */
put_header(s, SLICE_MIN_START_CODE);
put_bits(&s->pb, 5, 1); /* quantizer scale */
put_bits(&s->pb, 1, 0); /* slice extra information */
encode_mb_skip_run(s, 0);
/* empty macroblock */
put_bits(&s->pb, 3, 1); /* motion only */
/* zero motion x & y */
put_bits(&s->pb, 1, 1);
put_bits(&s->pb, 1, 1);
/* output a number of empty slice */
encode_mb_skip_run(s, s->mb_width * s->mb_height - 2);
/* empty macroblock */
put_bits(&s->pb, 3, 1); /* motion only */
/* zero motion x & y */
put_bits(&s->pb, 1, 1);
put_bits(&s->pb, 1, 1);
}
static void common_init(MpegEncContext *s)
{
s->y_dc_scale_table=
s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
}
#ifdef CONFIG_ENCODERS
void ff_mpeg1_encode_slice_header(MpegEncContext *s){
put_header(s, SLICE_MIN_START_CODE + s->mb_y);
put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
put_bits(&s->pb, 1, 0); /* slice extra information */
}
void ff_mpeg1_clean_buffers(MpegEncContext *s){
s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
s->last_dc[1] = s->last_dc[0];
s->last_dc[2] = s->last_dc[0];
memset(s->last_mv, 0, sizeof(s->last_mv));
}
void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
{
mpeg1_encode_sequence_header(s);
/* mpeg1 picture header */
put_header(s, PICTURE_START_CODE);
/* temporal reference */
// RAL: s->picture_number instead of s->fake_picture_number
put_bits(&s->pb, 10, (s->picture_number -
s->gop_picture_number) & 0x3ff);
s->fake_picture_number++;
put_bits(&s->pb, 3, s->pict_type);
put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
// RAL: Forward f_code also needed for B frames
if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
put_bits(&s->pb, 1, 0); /* half pel coordinates */
put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
}
// RAL: Backward f_code necessary for B frames
if (s->pict_type == B_TYPE) {
put_bits(&s->pb, 1, 0); /* half pel coordinates */
put_bits(&s->pb, 3, s->b_code); /* backward_f_code */
}
put_bits(&s->pb, 1, 0); /* extra bit picture */
s->mb_y=0;
ff_mpeg1_encode_slice_header(s);
}
void mpeg1_encode_mb(MpegEncContext *s,
DCTELEM block[6][64],
int motion_x, int motion_y)
{
int i, cbp;
const int mb_x = s->mb_x;
const int mb_y = s->mb_y;
const int first_mb= mb_x == s->resync_mb_x && mb_y == s->resync_mb_y;
/* compute cbp */
cbp = 0;
for(i=0;i<6;i++) {
if (s->block_last_index[i] >= 0)
cbp |= 1 << (5 - i);
}
if (cbp == 0 && !first_mb && (mb_x != s->mb_width - 1 || mb_y != s->mb_height - 1) &&
((s->pict_type == P_TYPE && (motion_x | motion_y) == 0) ||
(s->pict_type == B_TYPE && s->mv_dir == s->last_mv_dir && (((s->mv_dir & MV_DIR_FORWARD) ? ((s->mv[0][0][0] - s->last_mv[0][0][0])|(s->mv[0][0][1] - s->last_mv[0][0][1])) : 0) |
((s->mv_dir & MV_DIR_BACKWARD) ? ((s->mv[1][0][0] - s->last_mv[1][0][0])|(s->mv[1][0][1] - s->last_mv[1][0][1])) : 0)) == 0))) {
s->mb_skip_run++;
s->qscale -= s->dquant;
s->skip_count++;
s->misc_bits++;
s->last_bits++;
} else {
if(first_mb){
assert(s->mb_skip_run == 0);
encode_mb_skip_run(s, s->mb_x);
}else{
encode_mb_skip_run(s, s->mb_skip_run);
}
if (s->pict_type == I_TYPE) {
if(s->dquant && cbp){
put_bits(&s->pb, 2, 1); /* macroblock_type : macroblock_quant = 1 */
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
s->qscale -= s->dquant;
}
s->misc_bits+= get_bits_diff(s);
s->i_count++;
} else if (s->mb_intra) {
if(s->dquant && cbp){
put_bits(&s->pb, 6, 0x01);
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 5, 0x03);
s->qscale -= s->dquant;
}
s->misc_bits+= get_bits_diff(s);
s->i_count++;
s->last_mv[0][0][0] =
s->last_mv[0][0][1] = 0;
} else if (s->pict_type == P_TYPE) {
if (cbp != 0) {
if (motion_x == 0 && motion_y == 0) {
if(s->dquant){
put_bits(&s->pb, 5, 1); /* macroblock_pattern & quant */
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
}
s->misc_bits+= get_bits_diff(s);
put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
} else {
if(s->dquant){
put_bits(&s->pb, 5, 2); /* motion + cbp */
put_bits(&s->pb, 5, s->qscale);
}else{
put_bits(&s->pb, 1, 1); /* motion + cbp */
}
s->misc_bits+= get_bits_diff(s);
mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); // RAL: f_code parameter added
mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); // RAL: f_code parameter added
s->mv_bits+= get_bits_diff(s);
put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
}
} else {
put_bits(&s->pb, 3, 1); /* motion only */
mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); // RAL: f_code parameter added
mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); // RAL: f_code parameter added
s->qscale -= s->dquant;
s->mv_bits+= get_bits_diff(s);
}
s->f_count++;
} else
{ // RAL: All the following bloc added for B frames:
if (cbp != 0)
{ // With coded bloc pattern
if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
{ // Bi-directional motion
if (s->dquant)
{ // With QScale
put_bits(&s->pb, 5, 2);
put_bits(&s->pb, 5, s->qscale);
}
else // Without QScale
put_bits(&s->pb, 2, 3);
s->misc_bits += get_bits_diff(s);
mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
s->b_count++;
s->f_count++;
s->mv_bits += get_bits_diff(s);
put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
}
else if (s->mv_dir == MV_DIR_BACKWARD)
{ // Backward motion
if (s->dquant)
{ // With QScale
put_bits(&s->pb, 6, 2);
put_bits(&s->pb, 5, s->qscale);
}
else // Without QScale
put_bits(&s->pb, 3, 3);
s->misc_bits += get_bits_diff(s);
mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
s->b_count++;
s->mv_bits += get_bits_diff(s);
put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
}
else if (s->mv_dir == MV_DIR_FORWARD)
{ // Forward motion
if (s->dquant)
{ // With QScale
put_bits(&s->pb, 6, 3);
put_bits(&s->pb, 5, s->qscale);
}
else // Without QScale
put_bits(&s->pb, 4, 3);
s->misc_bits += get_bits_diff(s);
mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
s->f_count++;
s->mv_bits += get_bits_diff(s);
put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
}
}
else
{ // No coded bloc pattern
if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
{ // Bi-directional motion
put_bits(&s->pb, 2, 2); /* backward & forward motion */
mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
s->b_count++;
s->f_count++;
}
else if (s->mv_dir == MV_DIR_BACKWARD)
{ // Backward motion
put_bits(&s->pb, 3, 2); /* backward motion only */
mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code);
mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code);
s->b_count++;
}
else if (s->mv_dir == MV_DIR_FORWARD)
{ // Forward motion
put_bits(&s->pb, 4, 2); /* forward motion only */
mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);
mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);
s->f_count++;
}
s->qscale -= s->dquant;
s->mv_bits += get_bits_diff(s);
}
// End of bloc from RAL
}
for(i=0;i<6;i++) {
if (cbp & (1 << (5 - i))) {
mpeg1_encode_block(s, block[i], i);
}
}
s->mb_skip_run = 0;
if(s->mb_intra)
s->i_tex_bits+= get_bits_diff(s);
else
s->p_tex_bits+= get_bits_diff(s);
}
// RAL: By this:
if (s->mv_dir & MV_DIR_FORWARD)
{
s->last_mv[0][0][0]= s->mv[0][0][0];
s->last_mv[0][0][1]= s->mv[0][0][1];
}
if (s->mv_dir & MV_DIR_BACKWARD)
{
s->last_mv[1][0][0]= s->mv[1][0][0];
s->last_mv[1][0][1]= s->mv[1][0][1];
}
}
// RAL: Parameter added: f_or_b_code
static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code)
{
int code, bit_size, l, m, bits, range, sign;
if (val == 0) {
/* zero vector */
code = 0;
put_bits(&s->pb,
mbMotionVectorTable[0][1],
mbMotionVectorTable[0][0]);
} else {
bit_size = f_or_b_code - 1;
range = 1 << bit_size;
/* modulo encoding */
l = 16 * range;
m = 2 * l;
if (val < -l) {
val += m;
} else if (val >= l) {
val -= m;
}
if (val >= 0) {
val--;
code = (val >> bit_size) + 1;
bits = val & (range - 1);
sign = 0;
} else {
val = -val;
val--;
code = (val >> bit_size) + 1;
bits = val & (range - 1);
sign = 1;
}
assert(code > 0 && code <= 16);
put_bits(&s->pb,
mbMotionVectorTable[code][1],
mbMotionVectorTable[code][0]);
put_bits(&s->pb, 1, sign);
if (bit_size > 0) {
put_bits(&s->pb, bit_size, bits);
}
}
}
void ff_mpeg1_encode_init(MpegEncContext *s)
{
static int done=0;
common_init(s);
if(!done){
int f_code;
int mv;
int i;
done=1;
init_rl(&rl_mpeg1);
for(i=0; i<64; i++)
{
mpeg1_max_level[0][i]= rl_mpeg1.max_level[0][i];
mpeg1_index_run[0][i]= rl_mpeg1.index_run[0][i];
}
init_uni_ac_vlc(&rl_mpeg1, uni_mpeg1_ac_vlc_bits, uni_mpeg1_ac_vlc_len);
/* build unified dc encoding tables */
for(i=-255; i<256; i++)
{
int adiff, index;
int bits, code;
int diff=i;
adiff = ABS(diff);
if(diff<0) diff--;
index = vlc_dc_table[adiff];
bits= vlc_dc_lum_bits[index] + index;
code= (vlc_dc_lum_code[index]<<index) + (diff & ((1 << index) - 1));
mpeg1_lum_dc_uni[i+255]= bits + (code<<8);
bits= vlc_dc_chroma_bits[index] + index;
code= (vlc_dc_chroma_code[index]<<index) + (diff & ((1 << index) - 1));
mpeg1_chr_dc_uni[i+255]= bits + (code<<8);
}
mv_penalty= av_mallocz( sizeof(uint8_t)*(MAX_FCODE+1)*(2*MAX_MV+1) );
for(f_code=1; f_code<=MAX_FCODE; f_code++){
for(mv=-MAX_MV; mv<=MAX_MV; mv++){
int len;
if(mv==0) len= mbMotionVectorTable[0][1];
else{
int val, bit_size, range, code;
bit_size = s->f_code - 1;
range = 1 << bit_size;
val=mv;
if (val < 0)
val = -val;
val--;
code = (val >> bit_size) + 1;
if(code<17){
len= mbMotionVectorTable[code][1] + 1 + bit_size;
}else{
len= mbMotionVectorTable[16][1] + 2 + bit_size;
}
}
mv_penalty[f_code][mv+MAX_MV]= len;
}
}
for(f_code=MAX_FCODE; f_code>0; f_code--){
for(mv=-(8<<f_code); mv<(8<<f_code); mv++){
fcode_tab[mv+MAX_MV]= f_code;
}
}
}
s->me.mv_penalty= mv_penalty;
s->fcode_tab= fcode_tab;
s->min_qcoeff=-255;
s->max_qcoeff= 255;
s->intra_ac_vlc_length=
s->inter_ac_vlc_length= uni_mpeg1_ac_vlc_len;
}
static inline void encode_dc(MpegEncContext *s, int diff, int component)
{
if (component == 0) {
put_bits(
&s->pb,
mpeg1_lum_dc_uni[diff+255]&0xFF,
mpeg1_lum_dc_uni[diff+255]>>8);
} else {
put_bits(
&s->pb,
mpeg1_chr_dc_uni[diff+255]&0xFF,
mpeg1_chr_dc_uni[diff+255]>>8);
}
}
static void mpeg1_encode_block(MpegEncContext *s,
DCTELEM *block,
int n)
{
int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
int code, component;
// RLTable *rl = &rl_mpeg1;
last_index = s->block_last_index[n];
/* DC coef */
if (s->mb_intra) {
component = (n <= 3 ? 0 : n - 4 + 1);
dc = block[0]; /* overflow is impossible */
diff = dc - s->last_dc[component];
encode_dc(s, diff, component);
s->last_dc[component] = dc;
i = 1;
} else {
/* encode the first coefficient : needs to be done here because
it is handled slightly differently */
level = block[0];
if (abs(level) == 1) {
code = ((uint32_t)level >> 31); /* the sign bit */
put_bits(&s->pb, 2, code | 0x02);
i = 1;
} else {
i = 0;
last_non_zero = -1;
goto next_coef;
}
}
/* now quantify & encode AC coefs */
last_non_zero = i - 1;
for(;i<=last_index;i++) {
j = s->intra_scantable.permutated[i];
level = block[j];
next_coef:
#if 0
if (level != 0)
dprintf("level[%d]=%d\n", i, level);
#endif
/* encode using VLC */
if (level != 0) {
run = i - last_non_zero - 1;
alevel= level;
MASK_ABS(sign, alevel)
sign&=1;
// code = get_rl_index(rl, 0, run, alevel);
if (alevel <= mpeg1_max_level[0][run]){
code= mpeg1_index_run[0][run] + alevel - 1;
/* store the vlc & sign at once */
put_bits(&s->pb, mpeg1_vlc[code][1]+1, (mpeg1_vlc[code][0]<<1) + sign);
} else {
/* escape seems to be pretty rare <5% so i dont optimize it */
put_bits(&s->pb, mpeg1_vlc[111/*rl->n*/][1], mpeg1_vlc[111/*rl->n*/][0]);
/* escape: only clip in this case */
put_bits(&s->pb, 6, run);
if (alevel < 128) {
put_bits(&s->pb, 8, level & 0xff);
} else {
if (level < 0) {
put_bits(&s->pb, 16, 0x8001 + level + 255);
} else {
put_bits(&s->pb, 16, level & 0xffff);
}
}
}
last_non_zero = i;
}
}
/* end of block */
put_bits(&s->pb, 2, 0x2);
}
#endif //CONFIG_ENCODERS
/******************************************/
/* decoding */
static VLC dc_lum_vlc;
static VLC dc_chroma_vlc;
static VLC mv_vlc;
static VLC mbincr_vlc;
static VLC mb_ptype_vlc;
static VLC mb_btype_vlc;
static VLC mb_pat_vlc;
static void init_vlcs(MpegEncContext *s)
{
static int done = 0;
if (!done) {
done = 1;
init_vlc(&dc_lum_vlc, DC_VLC_BITS, 12,
vlc_dc_lum_bits, 1, 1,
vlc_dc_lum_code, 2, 2);
init_vlc(&dc_chroma_vlc, DC_VLC_BITS, 12,
vlc_dc_chroma_bits, 1, 1,
vlc_dc_chroma_code, 2, 2);
init_vlc(&mv_vlc, MV_VLC_BITS, 17,
&mbMotionVectorTable[0][1], 2, 1,
&mbMotionVectorTable[0][0], 2, 1);
init_vlc(&mbincr_vlc, MBINCR_VLC_BITS, 36,
&mbAddrIncrTable[0][1], 2, 1,
&mbAddrIncrTable[0][0], 2, 1);
init_vlc(&mb_pat_vlc, MB_PAT_VLC_BITS, 63,
&mbPatTable[0][1], 2, 1,
&mbPatTable[0][0], 2, 1);
init_vlc(&mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7,
&table_mb_ptype[0][1], 2, 1,
&table_mb_ptype[0][0], 2, 1);
init_vlc(&mb_btype_vlc, MB_BTYPE_VLC_BITS, 11,
&table_mb_btype[0][1], 2, 1,
&table_mb_btype[0][0], 2, 1);
init_rl(&rl_mpeg1);
init_rl(&rl_mpeg2);
init_2d_vlc_rl(&rl_mpeg1);
init_2d_vlc_rl(&rl_mpeg2);
}
}
static inline int get_dmv(MpegEncContext *s)
{
if(get_bits1(&s->gb))
return 1 - (get_bits1(&s->gb) << 1);
else
return 0;
}
static inline int get_qscale(MpegEncContext *s)
{
int qscale = get_bits(&s->gb, 5);
if (s->mpeg2) {
if (s->q_scale_type) {
return non_linear_qscale[qscale];
} else {
return qscale << 1;
}
}
return qscale;
}
/* motion type (for mpeg2) */
#define MT_FIELD 1
#define MT_FRAME 2
#define MT_16X8 2
#define MT_DMV 3
static int mpeg_decode_mb(MpegEncContext *s,
DCTELEM block[6][64])
{
int i, j, k, cbp, val, mb_type, motion_type;
dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
assert(s->mb_skiped==0);
if (s->mb_skip_run-- != 0) {
if(s->pict_type == I_TYPE){
fprintf(stderr, "skiped MB in I frame at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
/* skip mb */
s->mb_intra = 0;
for(i=0;i<6;i++)
s->block_last_index[i] = -1;
s->mv_type = MV_TYPE_16X16;
if (s->pict_type == P_TYPE) {
/* if P type, zero motion vector is implied */
s->mv_dir = MV_DIR_FORWARD;
s->mv[0][0][0] = s->mv[0][0][1] = 0;
s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
s->last_mv[0][1][0] = s->last_mv[0][1][1] = 0;
s->mb_skiped = 1;
s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= MB_TYPE_SKIP | MB_TYPE_L0 | MB_TYPE_16x16;
} else {
/* if B type, reuse previous vectors and directions */
s->mv[0][0][0] = s->last_mv[0][0][0];
s->mv[0][0][1] = s->last_mv[0][0][1];
s->mv[1][0][0] = s->last_mv[1][0][0];
s->mv[1][0][1] = s->last_mv[1][0][1];
s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]=
s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1] | MB_TYPE_SKIP;
// assert(s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride - 1]&(MB_TYPE_16x16|MB_TYPE_16x8));
if((s->mv[0][0][0]|s->mv[0][0][1]|s->mv[1][0][0]|s->mv[1][0][1])==0)
s->mb_skiped = 1;
}
return 0;
}
switch(s->pict_type) {
default:
case I_TYPE:
if (get_bits1(&s->gb) == 0) {
if (get_bits1(&s->gb) == 0)
return -1;
mb_type = MB_TYPE_QUANT | MB_TYPE_INTRA;
} else {
mb_type = MB_TYPE_INTRA;
}
break;
case P_TYPE:
mb_type = get_vlc2(&s->gb, mb_ptype_vlc.table, MB_PTYPE_VLC_BITS, 1);
if (mb_type < 0){
fprintf(stderr, "invalid mb type in P Frame at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
mb_type = ptype2mb_type[ mb_type ];
break;
case B_TYPE:
mb_type = get_vlc2(&s->gb, mb_btype_vlc.table, MB_BTYPE_VLC_BITS, 1);
if (mb_type < 0){
fprintf(stderr, "invalid mb type in B Frame at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
mb_type = btype2mb_type[ mb_type ];
break;
}
dprintf("mb_type=%x\n", mb_type);
// motion_type = 0; /* avoid warning */
if (IS_INTRA(mb_type)) {
/* compute dct type */
if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
!s->frame_pred_frame_dct) {
s->interlaced_dct = get_bits1(&s->gb);
}
if (IS_QUANT(mb_type))
s->qscale = get_qscale(s);
if (s->concealment_motion_vectors) {
/* just parse them */
if (s->picture_structure != PICT_FRAME)
skip_bits1(&s->gb); /* field select */
mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
skip_bits1(&s->gb); /* marker */
}
s->mb_intra = 1;
memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
if (s->mpeg2) {
for(i=0;i<6;i++) {
if (mpeg2_decode_block_intra(s, block[i], i) < 0)
return -1;
}
} else {
for(i=0;i<6;i++) {
if (mpeg1_decode_block_intra(s, block[i], i) < 0)
return -1;
}
}
} else {
if (mb_type & MB_TYPE_ZERO_MV){
assert(mb_type & MB_TYPE_PAT);
/* compute dct type */
if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
!s->frame_pred_frame_dct) {
s->interlaced_dct = get_bits1(&s->gb);
}
if (IS_QUANT(mb_type))
s->qscale = get_qscale(s);
s->mv_dir = MV_DIR_FORWARD;
s->mv_type = MV_TYPE_16X16;
s->last_mv[0][0][0] = 0;
s->last_mv[0][0][1] = 0;
s->last_mv[0][1][0] = 0;
s->last_mv[0][1][1] = 0;
s->mv[0][0][0] = 0;
s->mv[0][0][1] = 0;
}else{
assert(mb_type & MB_TYPE_L0L1);
//FIXME decide if MBs in field pictures are MB_TYPE_INTERLACED
/* get additionnal motion vector type */
if (s->frame_pred_frame_dct)
motion_type = MT_FRAME;
else{
motion_type = get_bits(&s->gb, 2);
}
/* compute dct type */
if (s->picture_structure == PICT_FRAME && //FIXME add a interlaced_dct coded var?
!s->frame_pred_frame_dct && IS_PAT(mb_type)) {
s->interlaced_dct = get_bits1(&s->gb);
}
if (IS_QUANT(mb_type))
s->qscale = get_qscale(s);
/* motion vectors */
s->mv_dir = 0;
for(i=0;i<2;i++) {
if (USES_LIST(mb_type, i)) {
s->mv_dir |= (MV_DIR_FORWARD >> i);
dprintf("motion_type=%d\n", motion_type);
switch(motion_type) {
case MT_FRAME: /* or MT_16X8 */
if (s->picture_structure == PICT_FRAME) {
/* MT_FRAME */
mb_type |= MB_TYPE_16x16;
s->mv_type = MV_TYPE_16X16;
s->mv[i][0][0]= s->last_mv[i][0][0]= s->last_mv[i][1][0] =
mpeg_decode_motion(s, s->mpeg_f_code[i][0], s->last_mv[i][0][0]);
s->mv[i][0][1]= s->last_mv[i][0][1]= s->last_mv[i][1][1] =
mpeg_decode_motion(s, s->mpeg_f_code[i][1], s->last_mv[i][0][1]);
/* full_pel: only for mpeg1 */
if (s->full_pel[i]){
s->mv[i][0][0] <<= 1;
s->mv[i][0][1] <<= 1;
}
} else {
/* MT_16X8 */
mb_type |= MB_TYPE_16x8;
s->mv_type = MV_TYPE_16X8;
for(j=0;j<2;j++) {
s->field_select[i][j] = get_bits1(&s->gb);
for(k=0;k<2;k++) {
val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
s->last_mv[i][j][k]);
s->last_mv[i][j][k] = val;
s->mv[i][j][k] = val;
}
}
}
break;
case MT_FIELD:
s->mv_type = MV_TYPE_FIELD;
if (s->picture_structure == PICT_FRAME) {
mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
for(j=0;j<2;j++) {
s->field_select[i][j] = get_bits1(&s->gb);
val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
s->last_mv[i][j][0]);
s->last_mv[i][j][0] = val;
s->mv[i][j][0] = val;
dprintf("fmx=%d\n", val);
val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
s->last_mv[i][j][1] >> 1);
s->last_mv[i][j][1] = val << 1;
s->mv[i][j][1] = val;
dprintf("fmy=%d\n", val);
}
} else {
mb_type |= MB_TYPE_16x16;
s->field_select[i][0] = get_bits1(&s->gb);
for(k=0;k<2;k++) {
val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
s->last_mv[i][0][k]);
s->last_mv[i][0][k] = val;
s->last_mv[i][1][k] = val;
s->mv[i][0][k] = val;
}
}
break;
case MT_DMV:
{
int dmx, dmy, mx, my, m;
mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
s->last_mv[i][0][0]);
s->last_mv[i][0][0] = mx;
s->last_mv[i][1][0] = mx;
dmx = get_dmv(s);
my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
s->last_mv[i][0][1] >> 1);
dmy = get_dmv(s);
s->mv_type = MV_TYPE_DMV;
/* XXX: totally broken */
if (s->picture_structure == PICT_FRAME) {
mb_type |= MB_TYPE_16x16 | MB_TYPE_INTERLACED;
s->last_mv[i][0][1] = my << 1;
s->last_mv[i][1][1] = my << 1;
m = s->top_field_first ? 1 : 3;
/* top -> top pred */
s->mv[i][0][0] = mx;
s->mv[i][0][1] = my << 1;
s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
m = 4 - m;
s->mv[i][2][0] = mx;
s->mv[i][2][1] = my << 1;
s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
} else {
mb_type |= MB_TYPE_16x16;
s->last_mv[i][0][1] = my;
s->last_mv[i][1][1] = my;
s->mv[i][0][0] = mx;
s->mv[i][0][1] = my;
s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
/* + 2 * cur_field */;
}
}
break;
}
}
}
}
s->mb_intra = 0;
if (IS_PAT(mb_type)) {
cbp = get_vlc2(&s->gb, mb_pat_vlc.table, MB_PAT_VLC_BITS, 1);
if (cbp < 0){
fprintf(stderr, "invalid cbp at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
cbp++;
if (s->mpeg2) {
for(i=0;i<6;i++) {
if (cbp & 32) {
if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
return -1;
} else {
s->block_last_index[i] = -1;
}
cbp+=cbp;
}
} else {
for(i=0;i<6;i++) {
if (cbp & 32) {
if (mpeg1_decode_block_inter(s, block[i], i) < 0)
return -1;
} else {
s->block_last_index[i] = -1;
}
cbp+=cbp;
}
}
}else{
for(i=0;i<6;i++)
s->block_last_index[i] = -1;
}
}
s->current_picture.mb_type[ s->mb_x + s->mb_y*s->mb_stride ]= mb_type;
return 0;
}
/* as h263, but only 17 codes */
static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
{
int code, sign, val, l, shift;
code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
if (code == 0) {
return pred;
}
if (code < 0) {
return 0xffff;
}
sign = get_bits1(&s->gb);
shift = fcode - 1;
val = code;
if (shift) {
val = (val - 1) << shift;
val |= get_bits(&s->gb, shift);
val++;
}
if (sign)
val = -val;
val += pred;
/* modulo decoding */
l = 1 << (shift+4);
val = ((val + l)&(l*2-1)) - l;
return val;
}
static inline int decode_dc(MpegEncContext *s, int component)
{
int code, diff;
if (component == 0) {
code = get_vlc2(&s->gb, dc_lum_vlc.table, DC_VLC_BITS, 2);
} else {
code = get_vlc2(&s->gb, dc_chroma_vlc.table, DC_VLC_BITS, 2);
}
if (code < 0){
fprintf(stderr, "invalid dc code at %d %d\n", s->mb_x, s->mb_y);
return 0xffff;
}
if (code == 0) {
diff = 0;
} else {
diff = get_xbits(&s->gb, code);
}
return diff;
}
static inline int mpeg1_decode_block_intra(MpegEncContext *s,
DCTELEM *block,
int n)
{
int level, dc, diff, i, j, run;
int component;
RLTable *rl = &rl_mpeg1;
uint8_t * const scantable= s->intra_scantable.permutated;
const uint16_t *quant_matrix= s->intra_matrix;
const int qscale= s->qscale;
/* DC coef */
component = (n <= 3 ? 0 : n - 4 + 1);
diff = decode_dc(s, component);
if (diff >= 0xffff)
return -1;
dc = s->last_dc[component];
dc += diff;
s->last_dc[component] = dc;
block[0] = dc<<3;
dprintf("dc=%d diff=%d\n", dc, diff);
i = 0;
{
OPEN_READER(re, &s->gb);
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
if(level == 127){
break;
} else if(level != 0) {
i += run;
j = scantable[i];
level= (level*qscale*quant_matrix[j])>>3;
level= (level-1)|1;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
if (level == -128) {
level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
} else if (level == 0) {
level = SHOW_UBITS(re, &s->gb, 8) ; LAST_SKIP_BITS(re, &s->gb, 8);
}
i += run;
j = scantable[i];
if(level<0){
level= -level;
level= (level*qscale*quant_matrix[j])>>3;
level= (level-1)|1;
level= -level;
}else{
level= (level*qscale*quant_matrix[j])>>3;
level= (level-1)|1;
}
}
if (i > 63){
fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
block[j] = level;
}
CLOSE_READER(re, &s->gb);
}
s->block_last_index[n] = i;
return 0;
}
static inline int mpeg1_decode_block_inter(MpegEncContext *s,
DCTELEM *block,
int n)
{
int level, i, j, run;
RLTable *rl = &rl_mpeg1;
uint8_t * const scantable= s->intra_scantable.permutated;
const uint16_t *quant_matrix= s->inter_matrix;
const int qscale= s->qscale;
{
int v;
OPEN_READER(re, &s->gb);
i = -1;
/* special case for the first coef. no need to add a second vlc table */
UPDATE_CACHE(re, &s->gb);
v= SHOW_UBITS(re, &s->gb, 2);
if (v & 2) {
LAST_SKIP_BITS(re, &s->gb, 2);
level= (3*qscale*quant_matrix[0])>>4;
level= (level-1)|1;
if(v&1)
level= -level;
block[0] = level;
i++;
}
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
if(level == 127){
break;
} else if(level != 0) {
i += run;
j = scantable[i];
level= ((level*2+1)*qscale*quant_matrix[j])>>4;
level= (level-1)|1;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 8); SKIP_BITS(re, &s->gb, 8);
if (level == -128) {
level = SHOW_UBITS(re, &s->gb, 8) - 256; LAST_SKIP_BITS(re, &s->gb, 8);
} else if (level == 0) {
level = SHOW_UBITS(re, &s->gb, 8) ; LAST_SKIP_BITS(re, &s->gb, 8);
}
i += run;
j = scantable[i];
if(level<0){
level= -level;
level= ((level*2+1)*qscale*quant_matrix[j])>>4;
level= (level-1)|1;
level= -level;
}else{
level= ((level*2+1)*qscale*quant_matrix[j])>>4;
level= (level-1)|1;
}
}
if (i > 63){
fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
block[j] = level;
}
CLOSE_READER(re, &s->gb);
}
s->block_last_index[n] = i;
return 0;
}
/* Also does unquantization here, since I will never support mpeg2
encoding */
static inline int mpeg2_decode_block_non_intra(MpegEncContext *s,
DCTELEM *block,
int n)
{
int level, i, j, run;
RLTable *rl = &rl_mpeg1;
uint8_t * const scantable= s->intra_scantable.permutated;
const uint16_t *quant_matrix;
const int qscale= s->qscale;
int mismatch;
mismatch = 1;
{
int v;
OPEN_READER(re, &s->gb);
i = -1;
if (n < 4)
quant_matrix = s->inter_matrix;
else
quant_matrix = s->chroma_inter_matrix;
/* special case for the first coef. no need to add a second vlc table */
UPDATE_CACHE(re, &s->gb);
v= SHOW_UBITS(re, &s->gb, 2);
if (v & 2) {
LAST_SKIP_BITS(re, &s->gb, 2);
level= (3*qscale*quant_matrix[0])>>5;
if(v&1)
level= -level;
block[0] = level;
mismatch ^= level;
i++;
}
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
if(level == 127){
break;
} else if(level != 0) {
i += run;
j = scantable[i];
level= ((level*2+1)*qscale*quant_matrix[j])>>5;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
i += run;
j = scantable[i];
if(level<0){
level= ((-level*2+1)*qscale*quant_matrix[j])>>5;
level= -level;
}else{
level= ((level*2+1)*qscale*quant_matrix[j])>>5;
}
}
if (i > 63){
fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
mismatch ^= level;
block[j] = level;
}
CLOSE_READER(re, &s->gb);
}
block[63] ^= (mismatch & 1);
s->block_last_index[n] = i;
return 0;
}
static inline int mpeg2_decode_block_intra(MpegEncContext *s,
DCTELEM *block,
int n)
{
int level, dc, diff, i, j, run;
int component;
RLTable *rl;
uint8_t * const scantable= s->intra_scantable.permutated;
const uint16_t *quant_matrix;
const int qscale= s->qscale;
int mismatch;
/* DC coef */
if (n < 4){
quant_matrix = s->intra_matrix;
component = 0;
}else{
quant_matrix = s->chroma_intra_matrix;
component = n - 3;
}
diff = decode_dc(s, component);
if (diff >= 0xffff)
return -1;
dc = s->last_dc[component];
dc += diff;
s->last_dc[component] = dc;
block[0] = dc << (3 - s->intra_dc_precision);
dprintf("dc=%d\n", block[0]);
mismatch = block[0] ^ 1;
i = 0;
if (s->intra_vlc_format)
rl = &rl_mpeg2;
else
rl = &rl_mpeg1;
{
OPEN_READER(re, &s->gb);
/* now quantify & encode AC coefs */
for(;;) {
UPDATE_CACHE(re, &s->gb);
GET_RL_VLC(level, run, re, &s->gb, rl->rl_vlc[0], TEX_VLC_BITS, 2);
if(level == 127){
break;
} else if(level != 0) {
i += run;
j = scantable[i];
level= (level*qscale*quant_matrix[j])>>4;
level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
LAST_SKIP_BITS(re, &s->gb, 1);
} else {
/* escape */
run = SHOW_UBITS(re, &s->gb, 6)+1; LAST_SKIP_BITS(re, &s->gb, 6);
UPDATE_CACHE(re, &s->gb);
level = SHOW_SBITS(re, &s->gb, 12); SKIP_BITS(re, &s->gb, 12);
i += run;
j = scantable[i];
if(level<0){
level= (-level*qscale*quant_matrix[j])>>4;
level= -level;
}else{
level= (level*qscale*quant_matrix[j])>>4;
}
}
if (i > 63){
fprintf(stderr, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
return -1;
}
mismatch^= level;
block[j] = level;
}
CLOSE_READER(re, &s->gb);
}
block[63]^= mismatch&1;
s->block_last_index[n] = i;
return 0;
}
typedef struct Mpeg1Context {
MpegEncContext mpeg_enc_ctx;
int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
int repeat_field; /* true if we must repeat the field */
} Mpeg1Context;
static int mpeg_decode_init(AVCodecContext *avctx)
{
Mpeg1Context *s = avctx->priv_data;
s->mpeg_enc_ctx.flags= avctx->flags;
common_init(&s->mpeg_enc_ctx);
init_vlcs(&s->mpeg_enc_ctx);
s->mpeg_enc_ctx_allocated = 0;
s->mpeg_enc_ctx.picture_number = 0;
s->repeat_field = 0;
s->mpeg_enc_ctx.codec_id= avctx->codec->id;
return 0;
}
/* return the 8 bit start code value and update the search
state. Return -1 if no start code found */
static int find_start_code(uint8_t **pbuf_ptr, uint8_t *buf_end)
{
uint8_t *buf_ptr;
unsigned int state=0xFFFFFFFF, v;
int val;
buf_ptr = *pbuf_ptr;
while (buf_ptr < buf_end) {
v = *buf_ptr++;
if (state == 0x000001) {
state = ((state << 8) | v) & 0xffffff;
val = state;
goto found;
}
state = ((state << 8) | v) & 0xffffff;
}
val = -1;
found:
*pbuf_ptr = buf_ptr;
return val;
}
static int mpeg1_decode_picture(AVCodecContext *avctx,
uint8_t *buf, int buf_size)
{
Mpeg1Context *s1 = avctx->priv_data;
MpegEncContext *s = &s1->mpeg_enc_ctx;
int ref, f_code;
init_get_bits(&s->gb, buf, buf_size*8);
ref = get_bits(&s->gb, 10); /* temporal ref */
s->pict_type = get_bits(&s->gb, 3);
dprintf("pict_type=%d number=%d\n", s->pict_type, s->picture_number);
skip_bits(&s->gb, 16);
if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
s->full_pel[0] = get_bits1(&s->gb);
f_code = get_bits(&s->gb, 3);
if (f_code == 0)
return -1;
s->mpeg_f_code[0][0] = f_code;
s->mpeg_f_code[0][1] = f_code;
}
if (s->pict_type == B_TYPE) {
s->full_pel[1] = get_bits1(&s->gb);
f_code = get_bits(&s->gb, 3);
if (f_code == 0)
return -1;
s->mpeg_f_code[1][0] = f_code;
s->mpeg_f_code[1][1] = f_code;
}
s->current_picture.pict_type= s->pict_type;
s->current_picture.key_frame= s->pict_type == I_TYPE;
s->y_dc_scale = 8;
s->c_dc_scale = 8;
s->first_slice = 1;
return 0;
}
static void mpeg_decode_sequence_extension(MpegEncContext *s)
{
int horiz_size_ext, vert_size_ext;
int bit_rate_ext, vbv_buf_ext;
int frame_rate_ext_n, frame_rate_ext_d;
float aspect;
skip_bits(&s->gb, 8); /* profil and level */
s->progressive_sequence = get_bits1(&s->gb); /* progressive_sequence */
skip_bits(&s->gb, 2); /* chroma_format */
horiz_size_ext = get_bits(&s->gb, 2);
vert_size_ext = get_bits(&s->gb, 2);
s->width |= (horiz_size_ext << 12);
s->height |= (vert_size_ext << 12);
bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */
s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
skip_bits1(&s->gb); /* marker */
vbv_buf_ext = get_bits(&s->gb, 8);
s->low_delay = get_bits1(&s->gb);
frame_rate_ext_n = get_bits(&s->gb, 2);
frame_rate_ext_d = get_bits(&s->gb, 5);
av_reduce(
&s->avctx->frame_rate,
&s->avctx->frame_rate_base,
frame_rate_tab[s->frame_rate_index] * (frame_rate_ext_n+1),
MPEG1_FRAME_RATE_BASE * (frame_rate_ext_d+1),
1<<30);
dprintf("sequence extension\n");
s->mpeg2 = 1;
s->avctx->sub_id = 2; /* indicates mpeg2 found */
aspect= mpeg2_aspect[s->aspect_ratio_info];
if(aspect>0.0) s->avctx->aspect_ratio= s->width/(aspect*s->height);
else if(aspect<0.0) s->avctx->aspect_ratio= -1.0/aspect;
}
static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
{
int i, v, j;
dprintf("matrix extension\n");
if (get_bits1(&s->gb)) {
for(i=0;i<64;i++) {
v = get_bits(&s->gb, 8);
j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
s->intra_matrix[j] = v;
s->chroma_intra_matrix[j] = v;
}
}
if (get_bits1(&s->gb)) {
for(i=0;i<64;i++) {
v = get_bits(&s->gb, 8);
j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
s->inter_matrix[j] = v;
s->chroma_inter_matrix[j] = v;
}
}
if (get_bits1(&s->gb)) {
for(i=0;i<64;i++) {
v = get_bits(&s->gb, 8);
j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
s->chroma_intra_matrix[j] = v;
}
}
if (get_bits1(&s->gb)) {
for(i=0;i<64;i++) {
v = get_bits(&s->gb, 8);
j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
s->chroma_inter_matrix[j] = v;
}
}
}
static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
{
s->full_pel[0] = s->full_pel[1] = 0;
s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
s->intra_dc_precision = get_bits(&s->gb, 2);
s->picture_structure = get_bits(&s->gb, 2);
s->top_field_first = get_bits1(&s->gb);
s->frame_pred_frame_dct = get_bits1(&s->gb);
s->concealment_motion_vectors = get_bits1(&s->gb);
s->q_scale_type = get_bits1(&s->gb);
s->intra_vlc_format = get_bits1(&s->gb);
s->alternate_scan = get_bits1(&s->gb);
s->repeat_first_field = get_bits1(&s->gb);
s->chroma_420_type = get_bits1(&s->gb);
s->progressive_frame = get_bits1(&s->gb);
if(s->picture_structure == PICT_FRAME)
s->first_field=0;
else{
s->first_field ^= 1;
memset(s->mbskip_table, 0, s->mb_stride*s->mb_height);
}
if(s->alternate_scan){
ff_init_scantable(s, &s->inter_scantable , ff_alternate_vertical_scan);
ff_init_scantable(s, &s->intra_scantable , ff_alternate_vertical_scan);
ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_vertical_scan);
ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
}else{
ff_init_scantable(s, &s->inter_scantable , ff_zigzag_direct);
ff_init_scantable(s, &s->intra_scantable , ff_zigzag_direct);
ff_init_scantable(s, &s->intra_h_scantable, ff_alternate_horizontal_scan);
ff_init_scantable(s, &s->intra_v_scantable, ff_alternate_vertical_scan);
}
/* composite display not parsed */
dprintf("intra_dc_precision=%d\n", s->intra_dc_precision);
dprintf("picture_structure=%d\n", s->picture_structure);
dprintf("top field first=%d\n", s->top_field_first);
dprintf("repeat first field=%d\n", s->repeat_first_field);
dprintf("conceal=%d\n", s->concealment_motion_vectors);
dprintf("intra_vlc_format=%d\n", s->intra_vlc_format);
dprintf("alternate_scan=%d\n", s->alternate_scan);
dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
dprintf("progressive_frame=%d\n", s->progressive_frame);
}
static void mpeg_decode_extension(AVCodecContext *avctx,
uint8_t *buf, int buf_size)
{
Mpeg1Context *s1 = avctx->priv_data;
MpegEncContext *s = &s1->mpeg_enc_ctx;
int ext_type;
init_get_bits(&s->gb, buf, buf_size*8);
ext_type = get_bits(&s->gb, 4);
switch(ext_type) {
case 0x1:
/* sequence ext */
mpeg_decode_sequence_extension(s);
break;
case 0x3:
/* quant matrix extension */
mpeg_decode_quant_matrix_extension(s);
break;
case 0x8:
/* picture extension */
mpeg_decode_picture_coding_extension(s);
break;
}
}
#define DECODE_SLICE_MB_ADDR_ERROR -3 //we faild decoding the mb_x/y info
#define DECODE_SLICE_FATAL_ERROR -2
#define DECODE_SLICE_ERROR -1
#define DECODE_SLICE_OK 0
#define DECODE_SLICE_EOP 1
/**
* decodes a slice.
* @return DECODE_SLICE_FATAL_ERROR if a non recoverable error occured<br>
* DECODE_SLICE_ERROR if the slice is damaged<br>
* DECODE_SLICE_OK if this slice is ok<br>
* DECODE_SLICE_EOP if the end of the picture is reached
*/
static int mpeg_decode_slice(AVCodecContext *avctx,
AVFrame *pict,
int start_code,
uint8_t **buf, int buf_size)
{
Mpeg1Context *s1 = avctx->priv_data;
MpegEncContext *s = &s1->mpeg_enc_ctx;
int ret;
const int field_pic= s->picture_structure != PICT_FRAME;
start_code = (start_code - 1) & 0xff;
if (start_code >= s->mb_height){
fprintf(stderr, "slice below image (%d >= %d)\n", start_code, s->mb_height);
return DECODE_SLICE_MB_ADDR_ERROR;
}
ff_mpeg1_clean_buffers(s);
s->interlaced_dct = 0;
/* start frame decoding */
if (s->first_slice) {
if(s->first_field || s->picture_structure==PICT_FRAME){
if(MPV_frame_start(s, avctx) < 0)
return DECODE_SLICE_FATAL_ERROR;
ff_er_frame_start(s);
/* first check if we must repeat the frame */
s->current_picture.repeat_pict = 0;
if (s->repeat_first_field) {
if (s->progressive_sequence) {
if (s->top_field_first)
s->current_picture.repeat_pict = 4;
else
s->current_picture.repeat_pict = 2;
} else if (s->progressive_frame) {
s->current_picture.repeat_pict = 1;
}
}
// printf("%d \n", s->current_picture.repeat_pict);
if(s->avctx->debug&FF_DEBUG_PICT_INFO){
printf("qp:%d fc:%2d%2d%2d%2d %s %s %s %s dc:%d pstruct:%d fdct:%d cmv:%d qtype:%d ivlc:%d rff:%d %s\n",
s->qscale, s->mpeg_f_code[0][0],s->mpeg_f_code[0][1],s->mpeg_f_code[1][0],s->mpeg_f_code[1][1],
s->pict_type == I_TYPE ? "I" : (s->pict_type == P_TYPE ? "P" : (s->pict_type == B_TYPE ? "B" : "S")),
s->progressive_sequence ? "pro" :"", s->alternate_scan ? "alt" :"", s->top_field_first ? "top" :"",
s->intra_dc_precision, s->picture_structure, s->frame_pred_frame_dct, s->concealment_motion_vectors,
s->q_scale_type, s->intra_vlc_format, s->repeat_first_field, s->chroma_420_type ? "420" :"");
}
}else{ //second field
int i;
if(!s->current_picture_ptr){
fprintf(stderr, "first field missing\n");
return -1;
}
for(i=0; i<4; i++){
s->current_picture.data[i] = s->current_picture_ptr->data[i];
if(s->picture_structure == PICT_BOTTOM_FIELD){
s->current_picture.data[i] += s->current_picture_ptr->linesize[i];
}
}
}
}
s->first_slice = 0;
init_get_bits(&s->gb, *buf, buf_size*8);
s->qscale = get_qscale(s);
if(s->qscale == 0){
fprintf(stderr, "qscale == 0\n");
return DECODE_SLICE_MB_ADDR_ERROR;
}
/* extra slice info */
while (get_bits1(&s->gb) != 0) {
skip_bits(&s->gb, 8);
}
s->mb_x=0;
for(;;) {
int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
if (code < 0){
fprintf(stderr, "first mb_incr damaged\n");
return DECODE_SLICE_MB_ADDR_ERROR;
}
if (code >= 33) {
if (code == 33) {
s->mb_x += 33;
}
/* otherwise, stuffing, nothing to do */
} else {
s->mb_x += code;
break;
}
}
s->resync_mb_x= s->mb_x;
s->resync_mb_y= s->mb_y = start_code;
s->mb_skip_run= 0;
for(;;) {
s->dsp.clear_blocks(s->block[0]);
ret = mpeg_decode_mb(s, s->block);
dprintf("ret=%d\n", ret);
if (ret < 0)
return -1;
if(s->motion_val && s->pict_type != B_TYPE){ //note motion_val is normally NULL unless we want to extract the MVs
const int wrap = s->block_wrap[0];
const int xy = s->mb_x*2 + 1 + (s->mb_y*2 +1)*wrap;
int motion_x, motion_y;
if (s->mb_intra || s->mv_type == MV_TYPE_16X16) {
motion_x = s->mv[0][0][0];
motion_y = s->mv[0][0][1];
} else /*if (s->mv_type == MV_TYPE_FIELD)*/ {
motion_x = s->mv[0][0][0] + s->mv[0][1][0];
motion_y = s->mv[0][0][1] + s->mv[0][1][1];
motion_x = (motion_x>>1) | (motion_x&1);
}
s->motion_val[xy][0] = motion_x;
s->motion_val[xy][1] = motion_y;
s->motion_val[xy + 1][0] = motion_x;
s->motion_val[xy + 1][1] = motion_y;
s->motion_val[xy + wrap][0] = motion_x;
s->motion_val[xy + wrap][1] = motion_y;
s->motion_val[xy + 1 + wrap][0] = motion_x;
s->motion_val[xy + 1 + wrap][1] = motion_y;
}
MPV_decode_mb(s, s->block);
if (++s->mb_x >= s->mb_width) {
if(s->picture_structure==PICT_FRAME){
ff_draw_horiz_band(s, 16*s->mb_y, 16);
}else{
if(!s->first_field){
ff_draw_horiz_band(s, 32*s->mb_y, 32);
}
}
s->mb_x = 0;
s->mb_y++;
}
/* skip mb handling */
if (s->mb_skip_run == -1) {
/* read again increment */
s->mb_skip_run = 0;
for(;;) {
int code = get_vlc2(&s->gb, mbincr_vlc.table, MBINCR_VLC_BITS, 2);
if (code < 0){
fprintf(stderr, "mb incr damaged\n");
return -1;
}
if (code >= 33) {
if (code == 33) {
s->mb_skip_run += 33;
}else if(code == 35){
if(s->mb_skip_run != 0 || show_bits(&s->gb, 15) != 0){
fprintf(stderr, "slice missmatch\n");
return -1;
}
goto eos; /* end of slice */
}
/* otherwise, stuffing, nothing to do */
} else {
s->mb_skip_run += code;
break;
}
}
}
if(s->mb_y<<field_pic >= s->mb_height){
fprintf(stderr, "slice too long\n");
return DECODE_SLICE_ERROR;
}
}
eos: //end of slice
//printf("y %d %d %d %d\n", s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y);
ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
emms_c();
*buf += get_bits_count(&s->gb)/8 - 1;
//intf("%d %d %d %d\n", s->mb_y, s->mb_height, s->pict_type, s->picture_number);
/* end of slice reached */
if (s->mb_y<<field_pic == s->mb_height && !s->first_field) {
/* end of image */
if(s->mpeg2){
s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG2;
}else
s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_MPEG1;
ff_er_frame_end(s);
MPV_frame_end(s);
if (s->pict_type == B_TYPE || s->low_delay) {
*pict= *(AVFrame*)&s->current_picture;
ff_print_debug_info(s, s->current_picture_ptr);
} else {
s->picture_number++;
/* latency of 1 frame for I and P frames */
/* XXX: use another variable than picture_number */
if (s->last_picture_ptr != NULL) {
*pict= *(AVFrame*)&s->last_picture;
ff_print_debug_info(s, s->last_picture_ptr);
}
}
return DECODE_SLICE_EOP;
} else {
return DECODE_SLICE_OK;
}
}
static int mpeg1_decode_sequence(AVCodecContext *avctx,
uint8_t *buf, int buf_size)
{
Mpeg1Context *s1 = avctx->priv_data;
MpegEncContext *s = &s1->mpeg_enc_ctx;
int width, height, i, v, j;
float aspect;
init_get_bits(&s->gb, buf, buf_size*8);
width = get_bits(&s->gb, 12);
height = get_bits(&s->gb, 12);
s->aspect_ratio_info= get_bits(&s->gb, 4);
if(!s->mpeg2){
aspect= mpeg1_aspect[s->aspect_ratio_info];
if(aspect!=0.0) avctx->aspect_ratio= width/(aspect*height);
}
s->frame_rate_index = get_bits(&s->gb, 4);
if (s->frame_rate_index == 0)
return -1;
s->bit_rate = get_bits(&s->gb, 18) * 400;
if (get_bits1(&s->gb) == 0) /* marker */
return -1;
if (width <= 0 || height <= 0 ||
(width % 2) != 0 || (height % 2) != 0)
return -1;
if (width != s->width ||
height != s->height) {
/* start new mpeg1 context decoding */
s->out_format = FMT_MPEG1;
if (s1->mpeg_enc_ctx_allocated) {
MPV_common_end(s);
}
s->width = width;
s->height = height;
avctx->has_b_frames= 1;
s->avctx = avctx;
avctx->width = width;
avctx->height = height;
av_reduce(
&avctx->frame_rate,
&avctx->frame_rate_base,
frame_rate_tab[s->frame_rate_index],
MPEG1_FRAME_RATE_BASE, //FIXME store in allready reduced form
1<<30
);
avctx->bit_rate = s->bit_rate;
if (MPV_common_init(s) < 0)
return -1;
s1->mpeg_enc_ctx_allocated = 1;
}
skip_bits(&s->gb, 10); /* vbv_buffer_size */
skip_bits(&s->gb, 1);
/* get matrix */
if (get_bits1(&s->gb)) {
for(i=0;i<64;i++) {
v = get_bits(&s->gb, 8);
j = s->intra_scantable.permutated[i];
s->intra_matrix[j] = v;
s->chroma_intra_matrix[j] = v;
}
#ifdef DEBUG
dprintf("intra matrix present\n");
for(i=0;i<64;i++)
dprintf(" %d", s->intra_matrix[s->intra_scantable.permutated[i]]);
printf("\n");
#endif
} else {
for(i=0;i<64;i++) {
int j= s->dsp.idct_permutation[i];
v = ff_mpeg1_default_intra_matrix[i];
s->intra_matrix[j] = v;
s->chroma_intra_matrix[j] = v;
}
}
if (get_bits1(&s->gb)) {
for(i=0;i<64;i++) {
v = get_bits(&s->gb, 8);
j = s->intra_scantable.permutated[i];
s->inter_matrix[j] = v;
s->chroma_inter_matrix[j] = v;
}
#ifdef DEBUG
dprintf("non intra matrix present\n");
for(i=0;i<64;i++)
dprintf(" %d", s->inter_matrix[s->intra_scantable.permutated[i]]);
printf("\n");
#endif
} else {
for(i=0;i<64;i++) {
int j= s->dsp.idct_permutation[i];
v = ff_mpeg1_default_non_intra_matrix[i];
s->inter_matrix[j] = v;
s->chroma_inter_matrix[j] = v;
}
}
/* we set mpeg2 parameters so that it emulates mpeg1 */
s->progressive_sequence = 1;
s->progressive_frame = 1;
s->picture_structure = PICT_FRAME;
s->frame_pred_frame_dct = 1;
s->mpeg2 = 0;
avctx->sub_id = 1; /* indicates mpeg1 */
return 0;
}
static void mpeg_decode_user_data(AVCodecContext *avctx,
const uint8_t *buf, int buf_size)
{
const uint8_t *p;
int len, flags;
p = buf;
len = buf_size;
/* we parse the DTG active format information */
if (len >= 5 &&
p[0] == 'D' && p[1] == 'T' && p[2] == 'G' && p[3] == '1') {
flags = p[4];
p += 5;
len -= 5;
if (flags & 0x80) {
/* skip event id */
if (len < 2)
return;
p += 2;
len -= 2;
}
if (flags & 0x40) {
if (len < 1)
return;
avctx->dtg_active_format = p[0] & 0x0f;
}
}
}
/**
* finds the end of the current frame in the bitstream.
* @return the position of the first byte of the next frame, or -1
*/
static int mpeg1_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
ParseContext *pc= &s->parse_context;
int i;
uint32_t state;
state= pc->state;
i=0;
if(!pc->frame_start_found){
for(i=0; i<buf_size; i++){
state= (state<<8) | buf[i];
if(state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE){
i++;
pc->frame_start_found=1;
break;
}
}
}
if(pc->frame_start_found){
for(; i<buf_size; i++){
state= (state<<8) | buf[i];
if((state&0xFFFFFF00) == 0x100){
if(state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE){
pc->frame_start_found=0;
pc->state=-1;
return i-3;
}
}
}
}
pc->state= state;
return END_NOT_FOUND;
}
/* handle buffering and image synchronisation */
static int mpeg_decode_frame(AVCodecContext *avctx,
void *data, int *data_size,
uint8_t *buf, int buf_size)
{
Mpeg1Context *s = avctx->priv_data;
uint8_t *buf_end, *buf_ptr;
int ret, start_code, input_size;
AVFrame *picture = data;
MpegEncContext *s2 = &s->mpeg_enc_ctx;
dprintf("fill_buffer\n");
*data_size = 0;
/* special case for last picture */
if (buf_size == 0) {
if (s2->picture_number > 0) {
*picture= *(AVFrame*)&s2->next_picture;
*data_size = sizeof(AVFrame);
}
return 0;
}
if(s2->flags&CODEC_FLAG_TRUNCATED){
int next= mpeg1_find_frame_end(s2, buf, buf_size);
if( ff_combine_frame(s2, next, &buf, &buf_size) < 0 )
return buf_size;
}
buf_ptr = buf;
buf_end = buf + buf_size;
#if 0
if (s->repeat_field % 2 == 1) {
s->repeat_field++;
//fprintf(stderr,"\nRepeating last frame: %d -> %d! pict: %d %d", avctx->frame_number-1, avctx->frame_number,
// s2->picture_number, s->repeat_field);
if (avctx->flags & CODEC_FLAG_REPEAT_FIELD) {
*data_size = sizeof(AVPicture);
goto the_end;
}
}
#endif
for(;;) {
/* find start next code */
start_code = find_start_code(&buf_ptr, buf_end);
if (start_code < 0){
// printf("missing end of picture\n");
return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
}
/* prepare data for next start code */
input_size = buf_end - buf_ptr;
switch(start_code) {
case SEQ_START_CODE:
mpeg1_decode_sequence(avctx, buf_ptr,
input_size);
break;
case PICTURE_START_CODE:
/* we have a complete image : we try to decompress it */
mpeg1_decode_picture(avctx,
buf_ptr, input_size);
break;
case EXT_START_CODE:
mpeg_decode_extension(avctx,
buf_ptr, input_size);
break;
case USER_START_CODE:
mpeg_decode_user_data(avctx,
buf_ptr, input_size);
break;
default:
if (start_code >= SLICE_MIN_START_CODE &&
start_code <= SLICE_MAX_START_CODE) {
/* skip b frames if we dont have reference frames */
if(s2->last_picture_ptr==NULL && s2->pict_type==B_TYPE) break;
/* skip b frames if we are in a hurry */
if(avctx->hurry_up && s2->pict_type==B_TYPE) break;
/* skip everything if we are in a hurry>=5 */
if(avctx->hurry_up>=5) break;
if (!s->mpeg_enc_ctx_allocated) break;
ret = mpeg_decode_slice(avctx, picture,
start_code, &buf_ptr, input_size);
if (ret == DECODE_SLICE_EOP) {
if(s2->last_picture_ptr) //FIXME merge with the stuff in mpeg_decode_slice
*data_size = sizeof(AVPicture);
return FFMAX(0, buf_ptr - buf - s2->parse_context.last_index);
}else if(ret < 0){
if(ret == DECODE_SLICE_ERROR)
ff_er_add_slice(s2, s2->resync_mb_x, s2->resync_mb_y, s2->mb_x, s2->mb_y, AC_ERROR|DC_ERROR|MV_ERROR);
fprintf(stderr,"Error while decoding slice\n");
if(ret==DECODE_SLICE_FATAL_ERROR) return -1;
}
}
break;
}
}
}
static int mpeg_decode_end(AVCodecContext *avctx)
{
Mpeg1Context *s = avctx->priv_data;
if (s->mpeg_enc_ctx_allocated)
MPV_common_end(&s->mpeg_enc_ctx);
return 0;
}
AVCodec mpeg_decoder = {
"mpegvideo",
CODEC_TYPE_VIDEO,
CODEC_ID_MPEG1VIDEO,
sizeof(Mpeg1Context),
mpeg_decode_init,
NULL,
mpeg_decode_end,
mpeg_decode_frame,
CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED,
};
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