FFmpeg: libavcodec/mpeg4videodec.c Source File

00001 /*
00002  * MPEG4 decoder.
00003  * Copyright (c) 2000,2001 Fabrice Bellard
00004  * Copyright (c) 2002-2010 Michael Niedermayer <michaelni@gmx.at>
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include "mpegvideo.h"
00024 #include "mpeg4video.h"
00025 #include "h263.h"
00026 
00027 // The defines below define the number of bits that are read at once for
00028 // reading vlc values. Changing these may improve speed and data cache needs
00029 // be aware though that decreasing them may need the number of stages that is
00030 // passed to get_vlc* to be increased.
00031 #define SPRITE_TRAJ_VLC_BITS 6
00032 #define DC_VLC_BITS 9
00033 #define MB_TYPE_B_VLC_BITS 4
00034 
00035 
00036 static VLC dc_lum, dc_chrom;
00037 static VLC sprite_trajectory;
00038 static VLC mb_type_b_vlc;
00039 
00040 static const int mb_type_b_map[4]= {
00041     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
00042     MB_TYPE_L0L1 | MB_TYPE_16x16,
00043     MB_TYPE_L1 | MB_TYPE_16x16,
00044     MB_TYPE_L0 | MB_TYPE_16x16,
00045 };
00046 
00052 void mpeg4_pred_ac(MpegEncContext * s, DCTELEM *block, int n,
00053                    int dir)
00054 {
00055     int i;
00056     int16_t *ac_val, *ac_val1;
00057     int8_t * const qscale_table= s->current_picture.qscale_table;
00058 
00059     /* find prediction */
00060     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
00061     ac_val1 = ac_val;
00062     if (s->ac_pred) {
00063         if (dir == 0) {
00064             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
00065             /* left prediction */
00066             ac_val -= 16;
00067 
00068             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
00069                 /* same qscale */
00070                 for(i=1;i<8;i++) {
00071                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
00072                 }
00073             }else{
00074                 /* different qscale, we must rescale */
00075                 for(i=1;i<8;i++) {
00076                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
00077                 }
00078             }
00079         } else {
00080             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
00081             /* top prediction */
00082             ac_val -= 16 * s->block_wrap[n];
00083 
00084             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
00085                 /* same qscale */
00086                 for(i=1;i<8;i++) {
00087                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
00088                 }
00089             }else{
00090                 /* different qscale, we must rescale */
00091                 for(i=1;i<8;i++) {
00092                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
00093                 }
00094             }
00095         }
00096     }
00097     /* left copy */
00098     for(i=1;i<8;i++)
00099         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
00100 
00101     /* top copy */
00102     for(i=1;i<8;i++)
00103         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
00104 
00105 }
00106 
00111 static inline int mpeg4_is_resync(MpegEncContext *s){
00112     int bits_count= get_bits_count(&s->gb);
00113     int v= show_bits(&s->gb, 16);
00114 
00115     if(s->workaround_bugs&FF_BUG_NO_PADDING){
00116         return 0;
00117     }
00118 
00119     while(v<=0xFF){
00120         if(s->pict_type==FF_B_TYPE || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
00121             break;
00122         skip_bits(&s->gb, 8+s->pict_type);
00123         bits_count+= 8+s->pict_type;
00124         v= show_bits(&s->gb, 16);
00125     }
00126 
00127     if(bits_count + 8 >= s->gb.size_in_bits){
00128         v>>=8;
00129         v|= 0x7F >> (7-(bits_count&7));
00130 
00131         if(v==0x7F)
00132             return 1;
00133     }else{
00134         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
00135             int len;
00136             GetBitContext gb= s->gb;
00137 
00138             skip_bits(&s->gb, 1);
00139             align_get_bits(&s->gb);
00140 
00141             for(len=0; len<32; len++){
00142                 if(get_bits1(&s->gb)) break;
00143             }
00144 
00145             s->gb= gb;
00146 
00147             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
00148                 return 1;
00149         }
00150     }
00151     return 0;
00152 }
00153 
00154 static void mpeg4_decode_sprite_trajectory(MpegEncContext * s, GetBitContext *gb)
00155 {
00156     int i;
00157     int a= 2<<s->sprite_warping_accuracy;
00158     int rho= 3-s->sprite_warping_accuracy;
00159     int r=16/a;
00160     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
00161     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
00162     int sprite_ref[4][2];
00163     int virtual_ref[2][2];
00164     int w2, h2, w3, h3;
00165     int alpha=0, beta=0;
00166     int w= s->width;
00167     int h= s->height;
00168     int min_ab;
00169 
00170     for(i=0; i<s->num_sprite_warping_points; i++){
00171         int length;
00172         int x=0, y=0;
00173 
00174         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
00175         if(length){
00176             x= get_xbits(gb, length);
00177         }
00178         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
00179 
00180         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
00181         if(length){
00182             y=get_xbits(gb, length);
00183         }
00184         skip_bits1(gb); /* marker bit */
00185         s->sprite_traj[i][0]= d[i][0]= x;
00186         s->sprite_traj[i][1]= d[i][1]= y;
00187     }
00188     for(; i<4; i++)
00189         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
00190 
00191     while((1<<alpha)<w) alpha++;
00192     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
00193     w2= 1<<alpha;
00194     h2= 1<<beta;
00195 
00196 // Note, the 4th point isn't used for GMC
00197     if(s->divx_version==500 && s->divx_build==413){
00198         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
00199         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
00200         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
00201         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
00202         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
00203         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
00204     } else {
00205         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
00206         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
00207         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
00208         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
00209         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
00210         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
00211     }
00212 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
00213     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
00214 
00215 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
00216 // perhaps it should be reordered to be more readable ...
00217 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
00218 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
00219     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
00220         + ROUNDED_DIV(((w - w2)*(r*sprite_ref[0][0] - 16*vop_ref[0][0]) + w2*(r*sprite_ref[1][0] - 16*vop_ref[1][0])),w);
00221     virtual_ref[0][1]= 16*vop_ref[0][1]
00222         + ROUNDED_DIV(((w - w2)*(r*sprite_ref[0][1] - 16*vop_ref[0][1]) + w2*(r*sprite_ref[1][1] - 16*vop_ref[1][1])),w);
00223     virtual_ref[1][0]= 16*vop_ref[0][0]
00224         + ROUNDED_DIV(((h - h2)*(r*sprite_ref[0][0] - 16*vop_ref[0][0]) + h2*(r*sprite_ref[2][0] - 16*vop_ref[2][0])),h);
00225     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
00226         + ROUNDED_DIV(((h - h2)*(r*sprite_ref[0][1] - 16*vop_ref[0][1]) + h2*(r*sprite_ref[2][1] - 16*vop_ref[2][1])),h);
00227 
00228     switch(s->num_sprite_warping_points)
00229     {
00230         case 0:
00231             s->sprite_offset[0][0]= 0;
00232             s->sprite_offset[0][1]= 0;
00233             s->sprite_offset[1][0]= 0;
00234             s->sprite_offset[1][1]= 0;
00235             s->sprite_delta[0][0]= a;
00236             s->sprite_delta[0][1]= 0;
00237             s->sprite_delta[1][0]= 0;
00238             s->sprite_delta[1][1]= a;
00239             s->sprite_shift[0]= 0;
00240             s->sprite_shift[1]= 0;
00241             break;
00242         case 1: //GMC only
00243             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
00244             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
00245             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
00246             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
00247             s->sprite_delta[0][0]= a;
00248             s->sprite_delta[0][1]= 0;
00249             s->sprite_delta[1][0]= 0;
00250             s->sprite_delta[1][1]= a;
00251             s->sprite_shift[0]= 0;
00252             s->sprite_shift[1]= 0;
00253             break;
00254         case 2:
00255             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
00256                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
00257                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
00258                                                   + (1<<(alpha+rho-1));
00259             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
00260                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
00261                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
00262                                                   + (1<<(alpha+rho-1));
00263             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
00264                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
00265                                      +2*w2*r*sprite_ref[0][0]
00266                                      - 16*w2
00267                                      + (1<<(alpha+rho+1)));
00268             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
00269                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
00270                                      +2*w2*r*sprite_ref[0][1]
00271                                      - 16*w2
00272                                      + (1<<(alpha+rho+1)));
00273             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
00274             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
00275             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
00276             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
00277 
00278             s->sprite_shift[0]= alpha+rho;
00279             s->sprite_shift[1]= alpha+rho+2;
00280             break;
00281         case 3:
00282             min_ab= FFMIN(alpha, beta);
00283             w3= w2>>min_ab;
00284             h3= h2>>min_ab;
00285             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
00286                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
00287                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
00288                                    + (1<<(alpha+beta+rho-min_ab-1));
00289             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
00290                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
00291                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
00292                                    + (1<<(alpha+beta+rho-min_ab-1));
00293             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
00294                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
00295                                    + 2*w2*h3*r*sprite_ref[0][0]
00296                                    - 16*w2*h3
00297                                    + (1<<(alpha+beta+rho-min_ab+1));
00298             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
00299                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
00300                                    + 2*w2*h3*r*sprite_ref[0][1]
00301                                    - 16*w2*h3
00302                                    + (1<<(alpha+beta+rho-min_ab+1));
00303             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
00304             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
00305             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
00306             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
00307 
00308             s->sprite_shift[0]= alpha + beta + rho - min_ab;
00309             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
00310             break;
00311     }
00312     /* try to simplify the situation */
00313     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
00314        && s->sprite_delta[0][1] == 0
00315        && s->sprite_delta[1][0] == 0
00316        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
00317     {
00318         s->sprite_offset[0][0]>>=s->sprite_shift[0];
00319         s->sprite_offset[0][1]>>=s->sprite_shift[0];
00320         s->sprite_offset[1][0]>>=s->sprite_shift[1];
00321         s->sprite_offset[1][1]>>=s->sprite_shift[1];
00322         s->sprite_delta[0][0]= a;
00323         s->sprite_delta[0][1]= 0;
00324         s->sprite_delta[1][0]= 0;
00325         s->sprite_delta[1][1]= a;
00326         s->sprite_shift[0]= 0;
00327         s->sprite_shift[1]= 0;
00328         s->real_sprite_warping_points=1;
00329     }
00330     else{
00331         int shift_y= 16 - s->sprite_shift[0];
00332         int shift_c= 16 - s->sprite_shift[1];
00333         for(i=0; i<2; i++){
00334             s->sprite_offset[0][i]<<= shift_y;
00335             s->sprite_offset[1][i]<<= shift_c;
00336             s->sprite_delta[0][i]<<= shift_y;
00337             s->sprite_delta[1][i]<<= shift_y;
00338             s->sprite_shift[i]= 16;
00339         }
00340         s->real_sprite_warping_points= s->num_sprite_warping_points;
00341     }
00342 }
00343 
00348 int mpeg4_decode_video_packet_header(MpegEncContext *s)
00349 {
00350     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
00351     int header_extension=0, mb_num, len;
00352 
00353     /* is there enough space left for a video packet + header */
00354     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
00355 
00356     for(len=0; len<32; len++){
00357         if(get_bits1(&s->gb)) break;
00358     }
00359 
00360     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
00361         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
00362         return -1;
00363     }
00364 
00365     if(s->shape != RECT_SHAPE){
00366         header_extension= get_bits1(&s->gb);
00367         //FIXME more stuff here
00368     }
00369 
00370     mb_num= get_bits(&s->gb, mb_num_bits);
00371     if(mb_num>=s->mb_num){
00372         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
00373         return -1;
00374     }
00375     if(s->pict_type == FF_B_TYPE){
00376         while(s->next_picture.mbskip_table[ s->mb_index2xy[ mb_num ] ]) mb_num++;
00377         if(mb_num >= s->mb_num) return -1; // slice contains just skipped MBs which where already decoded
00378     }
00379 
00380     s->mb_x= mb_num % s->mb_width;
00381     s->mb_y= mb_num / s->mb_width;
00382 
00383     if(s->shape != BIN_ONLY_SHAPE){
00384         int qscale= get_bits(&s->gb, s->quant_precision);
00385         if(qscale)
00386             s->chroma_qscale=s->qscale= qscale;
00387     }
00388 
00389     if(s->shape == RECT_SHAPE){
00390         header_extension= get_bits1(&s->gb);
00391     }
00392     if(header_extension){
00393         int time_increment;
00394         int time_incr=0;
00395 
00396         while (get_bits1(&s->gb) != 0)
00397             time_incr++;
00398 
00399         check_marker(&s->gb, "before time_increment in video packed header");
00400         time_increment= get_bits(&s->gb, s->time_increment_bits);
00401         check_marker(&s->gb, "before vop_coding_type in video packed header");
00402 
00403         skip_bits(&s->gb, 2); /* vop coding type */
00404         //FIXME not rect stuff here
00405 
00406         if(s->shape != BIN_ONLY_SHAPE){
00407             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
00408 //FIXME don't just ignore everything
00409             if(s->pict_type == FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
00410                 mpeg4_decode_sprite_trajectory(s, &s->gb);
00411                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
00412             }
00413 
00414             //FIXME reduced res stuff here
00415 
00416             if (s->pict_type != FF_I_TYPE) {
00417                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
00418                 if(f_code==0){
00419                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
00420                 }
00421             }
00422             if (s->pict_type == FF_B_TYPE) {
00423                 int b_code = get_bits(&s->gb, 3);
00424                 if(b_code==0){
00425                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
00426                 }
00427             }
00428         }
00429     }
00430     //FIXME new-pred stuff
00431 
00432     return 0;
00433 }
00434 
00440 static inline int get_amv(MpegEncContext *s, int n){
00441     int x, y, mb_v, sum, dx, dy, shift;
00442     int len = 1 << (s->f_code + 4);
00443     const int a= s->sprite_warping_accuracy;
00444 
00445     if(s->workaround_bugs & FF_BUG_AMV)
00446         len >>= s->quarter_sample;
00447 
00448     if(s->real_sprite_warping_points==1){
00449         if(s->divx_version==500 && s->divx_build==413)
00450             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
00451         else
00452             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
00453     }else{
00454         dx= s->sprite_delta[n][0];
00455         dy= s->sprite_delta[n][1];
00456         shift= s->sprite_shift[0];
00457         if(n) dy -= 1<<(shift + a + 1);
00458         else  dx -= 1<<(shift + a + 1);
00459         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
00460 
00461         sum=0;
00462         for(y=0; y<16; y++){
00463             int v;
00464 
00465             v= mb_v + dy*y;
00466             //XXX FIXME optimize
00467             for(x=0; x<16; x++){
00468                 sum+= v>>shift;
00469                 v+= dx;
00470             }
00471         }
00472         sum= RSHIFT(sum, a+8-s->quarter_sample);
00473     }
00474 
00475     if      (sum < -len) sum= -len;
00476     else if (sum >= len) sum= len-1;
00477 
00478     return sum;
00479 }
00480 
00487 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
00488 {
00489     int level, code;
00490 
00491     if (n < 4)
00492         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
00493     else
00494         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
00495     if (code < 0 || code > 9 /* && s->nbit<9 */){
00496         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
00497         return -1;
00498     }
00499     if (code == 0) {
00500         level = 0;
00501     } else {
00502         if(IS_3IV1){
00503             if(code==1)
00504                 level= 2*get_bits1(&s->gb)-1;
00505             else{
00506                 if(get_bits1(&s->gb))
00507                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
00508                 else
00509                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
00510             }
00511         }else{
00512             level = get_xbits(&s->gb, code);
00513         }
00514 
00515         if (code > 8){
00516             if(get_bits1(&s->gb)==0){ /* marker */
00517                 if(s->error_recognition>=2){
00518                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
00519                     return -1;
00520                 }
00521             }
00522         }
00523     }
00524 
00525     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
00526 }
00527 
00532 static int mpeg4_decode_partition_a(MpegEncContext *s){
00533     int mb_num;
00534     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
00535 
00536     /* decode first partition */
00537     mb_num=0;
00538     s->first_slice_line=1;
00539     for(; s->mb_y<s->mb_height; s->mb_y++){
00540         ff_init_block_index(s);
00541         for(; s->mb_x<s->mb_width; s->mb_x++){
00542             const int xy= s->mb_x + s->mb_y*s->mb_stride;
00543             int cbpc;
00544             int dir=0;
00545 
00546             mb_num++;
00547             ff_update_block_index(s);
00548             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
00549                 s->first_slice_line=0;
00550 
00551             if(s->pict_type==FF_I_TYPE){
00552                 int i;
00553 
00554                 do{
00555                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
00556                         return mb_num-1;
00557                     }
00558 
00559                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
00560                     if (cbpc < 0){
00561                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
00562                         return -1;
00563                     }
00564                 }while(cbpc == 8);
00565 
00566                 s->cbp_table[xy]= cbpc & 3;
00567                 s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
00568                 s->mb_intra = 1;
00569 
00570                 if(cbpc & 4) {
00571                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
00572                 }
00573                 s->current_picture.qscale_table[xy]= s->qscale;
00574 
00575                 s->mbintra_table[xy]= 1;
00576                 for(i=0; i<6; i++){
00577                     int dc_pred_dir;
00578                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
00579                     if(dc < 0){
00580                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
00581                         return -1;
00582                     }
00583                     dir<<=1;
00584                     if(dc_pred_dir) dir|=1;
00585                 }
00586                 s->pred_dir_table[xy]= dir;
00587             }else{ /* P/S_TYPE */
00588                 int mx, my, pred_x, pred_y, bits;
00589                 int16_t * const mot_val= s->current_picture.motion_val[0][s->block_index[0]];
00590                 const int stride= s->b8_stride*2;
00591 
00592 try_again:
00593                 bits= show_bits(&s->gb, 17);
00594                 if(bits==MOTION_MARKER){
00595                     return mb_num-1;
00596                 }
00597                 skip_bits1(&s->gb);
00598                 if(bits&0x10000){
00599                     /* skip mb */
00600                     if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
00601                         s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
00602                         mx= get_amv(s, 0);
00603                         my= get_amv(s, 1);
00604                     }else{
00605                         s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
00606                         mx=my=0;
00607                     }
00608                     mot_val[0       ]= mot_val[2       ]=
00609                     mot_val[0+stride]= mot_val[2+stride]= mx;
00610                     mot_val[1       ]= mot_val[3       ]=
00611                     mot_val[1+stride]= mot_val[3+stride]= my;
00612 
00613                     if(s->mbintra_table[xy])
00614                         ff_clean_intra_table_entries(s);
00615                     continue;
00616                 }
00617 
00618                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
00619                 if (cbpc < 0){
00620                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
00621                     return -1;
00622                 }
00623                 if(cbpc == 20)
00624                     goto try_again;
00625 
00626                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
00627 
00628                 s->mb_intra = ((cbpc & 4) != 0);
00629 
00630                 if(s->mb_intra){
00631                     s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
00632                     s->mbintra_table[xy]= 1;
00633                     mot_val[0       ]= mot_val[2       ]=
00634                     mot_val[0+stride]= mot_val[2+stride]= 0;
00635                     mot_val[1       ]= mot_val[3       ]=
00636                     mot_val[1+stride]= mot_val[3+stride]= 0;
00637                 }else{
00638                     if(s->mbintra_table[xy])
00639                         ff_clean_intra_table_entries(s);
00640 
00641                     if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
00642                         s->mcsel= get_bits1(&s->gb);
00643                     else s->mcsel= 0;
00644 
00645                     if ((cbpc & 16) == 0) {
00646                         /* 16x16 motion prediction */
00647 
00648                         h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
00649                         if(!s->mcsel){
00650                             mx = h263_decode_motion(s, pred_x, s->f_code);
00651                             if (mx >= 0xffff)
00652                                 return -1;
00653 
00654                             my = h263_decode_motion(s, pred_y, s->f_code);
00655                             if (my >= 0xffff)
00656                                 return -1;
00657                             s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
00658                         } else {
00659                             mx = get_amv(s, 0);
00660                             my = get_amv(s, 1);
00661                             s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
00662                         }
00663 
00664                         mot_val[0       ]= mot_val[2       ] =
00665                         mot_val[0+stride]= mot_val[2+stride]= mx;
00666                         mot_val[1       ]= mot_val[3       ]=
00667                         mot_val[1+stride]= mot_val[3+stride]= my;
00668                     } else {
00669                         int i;
00670                         s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0;
00671                         for(i=0;i<4;i++) {
00672                             int16_t *mot_val= h263_pred_motion(s, i, 0, &pred_x, &pred_y);
00673                             mx = h263_decode_motion(s, pred_x, s->f_code);
00674                             if (mx >= 0xffff)
00675                                 return -1;
00676 
00677                             my = h263_decode_motion(s, pred_y, s->f_code);
00678                             if (my >= 0xffff)
00679                                 return -1;
00680                             mot_val[0] = mx;
00681                             mot_val[1] = my;
00682                         }
00683                     }
00684                 }
00685             }
00686         }
00687         s->mb_x= 0;
00688     }
00689 
00690     return mb_num;
00691 }
00692 
00697 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
00698     int mb_num=0;
00699     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
00700 
00701     s->mb_x= s->resync_mb_x;
00702     s->first_slice_line=1;
00703     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
00704         ff_init_block_index(s);
00705         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
00706             const int xy= s->mb_x + s->mb_y*s->mb_stride;
00707 
00708             mb_num++;
00709             ff_update_block_index(s);
00710             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
00711                 s->first_slice_line=0;
00712 
00713             if(s->pict_type==FF_I_TYPE){
00714                 int ac_pred= get_bits1(&s->gb);
00715                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
00716                 if(cbpy<0){
00717                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
00718                     return -1;
00719                 }
00720 
00721                 s->cbp_table[xy]|= cbpy<<2;
00722                 s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
00723             }else{ /* P || S_TYPE */
00724                 if(IS_INTRA(s->current_picture.mb_type[xy])){
00725                     int dir=0,i;
00726                     int ac_pred = get_bits1(&s->gb);
00727                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
00728 
00729                     if(cbpy<0){
00730                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
00731                         return -1;
00732                     }
00733 
00734                     if(s->cbp_table[xy] & 8) {
00735                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
00736                     }
00737                     s->current_picture.qscale_table[xy]= s->qscale;
00738 
00739                     for(i=0; i<6; i++){
00740                         int dc_pred_dir;
00741                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
00742                         if(dc < 0){
00743                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
00744                             return -1;
00745                         }
00746                         dir<<=1;
00747                         if(dc_pred_dir) dir|=1;
00748                     }
00749                     s->cbp_table[xy]&= 3; //remove dquant
00750                     s->cbp_table[xy]|= cbpy<<2;
00751                     s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
00752                     s->pred_dir_table[xy]= dir;
00753                 }else if(IS_SKIP(s->current_picture.mb_type[xy])){
00754                     s->current_picture.qscale_table[xy]= s->qscale;
00755                     s->cbp_table[xy]= 0;
00756                 }else{
00757                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
00758 
00759                     if(cbpy<0){
00760                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
00761                         return -1;
00762                     }
00763 
00764                     if(s->cbp_table[xy] & 8) {
00765                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
00766                     }
00767                     s->current_picture.qscale_table[xy]= s->qscale;
00768 
00769                     s->cbp_table[xy]&= 3; //remove dquant
00770                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
00771                 }
00772             }
00773         }
00774         if(mb_num >= mb_count) return 0;
00775         s->mb_x= 0;
00776     }
00777     return 0;
00778 }
00779 
00784 int ff_mpeg4_decode_partitions(MpegEncContext *s)
00785 {
00786     int mb_num;
00787     const int part_a_error= s->pict_type==FF_I_TYPE ? (DC_ERROR|MV_ERROR) : MV_ERROR;
00788     const int part_a_end  = s->pict_type==FF_I_TYPE ? (DC_END  |MV_END)   : MV_END;
00789 
00790     mb_num= mpeg4_decode_partition_a(s);
00791     if(mb_num<0){
00792         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
00793         return -1;
00794     }
00795 
00796     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
00797         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
00798         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
00799         return -1;
00800     }
00801 
00802     s->mb_num_left= mb_num;
00803 
00804     if(s->pict_type==FF_I_TYPE){
00805         while(show_bits(&s->gb, 9) == 1)
00806             skip_bits(&s->gb, 9);
00807         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
00808             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
00809             return -1;
00810         }
00811     }else{
00812         while(show_bits(&s->gb, 10) == 1)
00813             skip_bits(&s->gb, 10);
00814         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
00815             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
00816             return -1;
00817         }
00818     }
00819     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
00820 
00821     if( mpeg4_decode_partition_b(s, mb_num) < 0){
00822         if(s->pict_type==FF_P_TYPE)
00823             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, DC_ERROR);
00824         return -1;
00825     }else{
00826         if(s->pict_type==FF_P_TYPE)
00827             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, DC_END);
00828     }
00829 
00830     return 0;
00831 }
00832 
00837 static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
00838                               int n, int coded, int intra, int rvlc)
00839 {
00840     int level, i, last, run;
00841     int dc_pred_dir;
00842     RLTable * rl;
00843     RL_VLC_ELEM * rl_vlc;
00844     const uint8_t * scan_table;
00845     int qmul, qadd;
00846 
00847     //Note intra & rvlc should be optimized away if this is inlined
00848 
00849     if(intra) {
00850       if(s->use_intra_dc_vlc){
00851         /* DC coef */
00852         if(s->partitioned_frame){
00853             level = s->dc_val[0][ s->block_index[n] ];
00854             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
00855             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
00856             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
00857         }else{
00858             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
00859             if (level < 0)
00860                 return -1;
00861         }
00862         block[0] = level;
00863         i = 0;
00864       }else{
00865             i = -1;
00866             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
00867       }
00868       if (!coded)
00869           goto not_coded;
00870 
00871       if(rvlc){
00872           rl = &rvlc_rl_intra;
00873           rl_vlc = rvlc_rl_intra.rl_vlc[0];
00874       }else{
00875           rl = &ff_mpeg4_rl_intra;
00876           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
00877       }
00878       if (s->ac_pred) {
00879           if (dc_pred_dir == 0)
00880               scan_table = s->intra_v_scantable.permutated; /* left */
00881           else
00882               scan_table = s->intra_h_scantable.permutated; /* top */
00883       } else {
00884             scan_table = s->intra_scantable.permutated;
00885       }
00886       qmul=1;
00887       qadd=0;
00888     } else {
00889         i = -1;
00890         if (!coded) {
00891             s->block_last_index[n] = i;
00892             return 0;
00893         }
00894         if(rvlc) rl = &rvlc_rl_inter;
00895         else     rl = &ff_h263_rl_inter;
00896 
00897         scan_table = s->intra_scantable.permutated;
00898 
00899         if(s->mpeg_quant){
00900             qmul=1;
00901             qadd=0;
00902             if(rvlc){
00903                 rl_vlc = rvlc_rl_inter.rl_vlc[0];
00904             }else{
00905                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
00906             }
00907         }else{
00908             qmul = s->qscale << 1;
00909             qadd = (s->qscale - 1) | 1;
00910             if(rvlc){
00911                 rl_vlc = rvlc_rl_inter.rl_vlc[s->qscale];
00912             }else{
00913                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
00914             }
00915         }
00916     }
00917   {
00918     OPEN_READER(re, &s->gb);
00919     for(;;) {
00920         UPDATE_CACHE(re, &s->gb);
00921         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
00922         if (level==0) {
00923           /* escape */
00924           if(rvlc){
00925                 if(SHOW_UBITS(re, &s->gb, 1)==0){
00926                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
00927                     return -1;
00928                 }; SKIP_CACHE(re, &s->gb, 1);
00929 
00930                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
00931                 run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
00932                 SKIP_COUNTER(re, &s->gb, 1+1+6);
00933                 UPDATE_CACHE(re, &s->gb);
00934 
00935                 if(SHOW_UBITS(re, &s->gb, 1)==0){
00936                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
00937                     return -1;
00938                 }; SKIP_CACHE(re, &s->gb, 1);
00939 
00940                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
00941 
00942                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
00943                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
00944                     return -1;
00945                 }; SKIP_CACHE(re, &s->gb, 5);
00946 
00947                 level=  level * qmul + qadd;
00948                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_CACHE(re, &s->gb, 1);
00949                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
00950 
00951                 i+= run + 1;
00952                 if(last) i+=192;
00953           }else{
00954             int cache;
00955             cache= GET_CACHE(re, &s->gb);
00956 
00957             if(IS_3IV1)
00958                 cache ^= 0xC0000000;
00959 
00960             if (cache&0x80000000) {
00961                 if (cache&0x40000000) {
00962                     /* third escape */
00963                     SKIP_CACHE(re, &s->gb, 2);
00964                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
00965                     run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
00966                     SKIP_COUNTER(re, &s->gb, 2+1+6);
00967                     UPDATE_CACHE(re, &s->gb);
00968 
00969                     if(IS_3IV1){
00970                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
00971                     }else{
00972                         if(SHOW_UBITS(re, &s->gb, 1)==0){
00973                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
00974                             return -1;
00975                         }; SKIP_CACHE(re, &s->gb, 1);
00976 
00977                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
00978 
00979                         if(SHOW_UBITS(re, &s->gb, 1)==0){
00980                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
00981                             return -1;
00982                         }; LAST_SKIP_CACHE(re, &s->gb, 1);
00983 
00984                         SKIP_COUNTER(re, &s->gb, 1+12+1);
00985                     }
00986 
00987 #if 0
00988                     if(s->error_recognition >= FF_ER_COMPLIANT){
00989                         const int abs_level= FFABS(level);
00990                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
00991                             const int run1= run - rl->max_run[last][abs_level] - 1;
00992                             if(abs_level <= rl->max_level[last][run]){
00993                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
00994                                 return -1;
00995                             }
00996                             if(s->error_recognition > FF_ER_COMPLIANT){
00997                                 if(abs_level <= rl->max_level[last][run]*2){
00998                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
00999                                     return -1;
01000                                 }
01001                                 if(run1 >= 0 && abs_level <= rl->max_level[last][run1]){
01002                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
01003                                     return -1;
01004                                 }
01005                             }
01006                         }
01007                     }
01008 #endif
01009                     if (level>0) level= level * qmul + qadd;
01010                     else         level= level * qmul - qadd;
01011 
01012                     if((unsigned)(level + 2048) > 4095){
01013                         if(s->error_recognition > FF_ER_COMPLIANT){
01014                             if(level > 2560 || level<-2560){
01015                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
01016                                 return -1;
01017                             }
01018                         }
01019                         level= level<0 ? -2048 : 2047;
01020                     }
01021 
01022                     i+= run + 1;
01023                     if(last) i+=192;
01024                 } else {
01025                     /* second escape */
01026 #if MIN_CACHE_BITS < 20
01027                     LAST_SKIP_BITS(re, &s->gb, 2);
01028                     UPDATE_CACHE(re, &s->gb);
01029 #else
01030                     SKIP_BITS(re, &s->gb, 2);
01031 #endif
01032                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
01033                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
01034                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
01035                     LAST_SKIP_BITS(re, &s->gb, 1);
01036                 }
01037             } else {
01038                 /* first escape */
01039 #if MIN_CACHE_BITS < 19
01040                 LAST_SKIP_BITS(re, &s->gb, 1);
01041                 UPDATE_CACHE(re, &s->gb);
01042 #else
01043                 SKIP_BITS(re, &s->gb, 1);
01044 #endif
01045                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
01046                 i+= run;
01047                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
01048                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
01049                 LAST_SKIP_BITS(re, &s->gb, 1);
01050             }
01051           }
01052         } else {
01053             i+= run;
01054             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
01055             LAST_SKIP_BITS(re, &s->gb, 1);
01056         }
01057         if (i > 62){
01058             i-= 192;
01059             if(i&(~63)){
01060                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
01061                 return -1;
01062             }
01063 
01064             block[scan_table[i]] = level;
01065             break;
01066         }
01067 
01068         block[scan_table[i]] = level;
01069     }
01070     CLOSE_READER(re, &s->gb);
01071   }
01072  not_coded:
01073     if (intra) {
01074         if(!s->use_intra_dc_vlc){
01075             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
01076 
01077             i -= i>>31; //if(i == -1) i=0;
01078         }
01079 
01080         mpeg4_pred_ac(s, block, n, dc_pred_dir);
01081         if (s->ac_pred) {
01082             i = 63; /* XXX: not optimal */
01083         }
01084     }
01085     s->block_last_index[n] = i;
01086     return 0;
01087 }
01088 
01093 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, DCTELEM block[6][64])
01094 {
01095     int cbp, mb_type;
01096     const int xy= s->mb_x + s->mb_y*s->mb_stride;
01097 
01098     mb_type= s->current_picture.mb_type[xy];
01099     cbp = s->cbp_table[xy];
01100 
01101     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
01102 
01103     if(s->current_picture.qscale_table[xy] != s->qscale){
01104         ff_set_qscale(s, s->current_picture.qscale_table[xy] );
01105     }
01106 
01107     if (s->pict_type == FF_P_TYPE || s->pict_type==FF_S_TYPE) {
01108         int i;
01109         for(i=0; i<4; i++){
01110             s->mv[0][i][0] = s->current_picture.motion_val[0][ s->block_index[i] ][0];
01111             s->mv[0][i][1] = s->current_picture.motion_val[0][ s->block_index[i] ][1];
01112         }
01113         s->mb_intra = IS_INTRA(mb_type);
01114 
01115         if (IS_SKIP(mb_type)) {
01116             /* skip mb */
01117             for(i=0;i<6;i++)
01118                 s->block_last_index[i] = -1;
01119             s->mv_dir = MV_DIR_FORWARD;
01120             s->mv_type = MV_TYPE_16X16;
01121             if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
01122                 s->mcsel=1;
01123                 s->mb_skipped = 0;
01124             }else{
01125                 s->mcsel=0;
01126                 s->mb_skipped = 1;
01127             }
01128         }else if(s->mb_intra){
01129             s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
01130         }else if(!s->mb_intra){
01131 //            s->mcsel= 0; //FIXME do we need to init that
01132 
01133             s->mv_dir = MV_DIR_FORWARD;
01134             if (IS_8X8(mb_type)) {
01135                 s->mv_type = MV_TYPE_8X8;
01136             } else {
01137                 s->mv_type = MV_TYPE_16X16;
01138             }
01139         }
01140     } else { /* I-Frame */
01141         s->mb_intra = 1;
01142         s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
01143     }
01144 
01145     if (!IS_SKIP(mb_type)) {
01146         int i;
01147         s->dsp.clear_blocks(s->block[0]);
01148         /* decode each block */
01149         for (i = 0; i < 6; i++) {
01150             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
01151                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
01152                 return -1;
01153             }
01154             cbp+=cbp;
01155         }
01156     }
01157 
01158     /* per-MB end of slice check */
01159 
01160     if(--s->mb_num_left <= 0){
01161         if(mpeg4_is_resync(s))
01162             return SLICE_END;
01163         else
01164             return SLICE_NOEND;
01165     }else{
01166         if(mpeg4_is_resync(s)){
01167             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
01168             if(s->cbp_table[xy+delta])
01169                 return SLICE_END;
01170         }
01171         return SLICE_OK;
01172     }
01173 }
01174 
01175 static int mpeg4_decode_mb(MpegEncContext *s,
01176                       DCTELEM block[6][64])
01177 {
01178     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
01179     int16_t *mot_val;
01180     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
01181     const int xy= s->mb_x + s->mb_y * s->mb_stride;
01182 
01183     assert(s->h263_pred);
01184 
01185     if (s->pict_type == FF_P_TYPE || s->pict_type==FF_S_TYPE) {
01186         do{
01187             if (get_bits1(&s->gb)) {
01188                 /* skip mb */
01189                 s->mb_intra = 0;
01190                 for(i=0;i<6;i++)
01191                     s->block_last_index[i] = -1;
01192                 s->mv_dir = MV_DIR_FORWARD;
01193                 s->mv_type = MV_TYPE_16X16;
01194                 if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
01195                     s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
01196                     s->mcsel=1;
01197                     s->mv[0][0][0]= get_amv(s, 0);
01198                     s->mv[0][0][1]= get_amv(s, 1);
01199 
01200                     s->mb_skipped = 0;
01201                 }else{
01202                     s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
01203                     s->mcsel=0;
01204                     s->mv[0][0][0] = 0;
01205                     s->mv[0][0][1] = 0;
01206                     s->mb_skipped = 1;
01207                 }
01208                 goto end;
01209             }
01210             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
01211             if (cbpc < 0){
01212                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
01213                 return -1;
01214             }
01215         }while(cbpc == 20);
01216 
01217         s->dsp.clear_blocks(s->block[0]);
01218         dquant = cbpc & 8;
01219         s->mb_intra = ((cbpc & 4) != 0);
01220         if (s->mb_intra) goto intra;
01221 
01222         if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
01223             s->mcsel= get_bits1(&s->gb);
01224         else s->mcsel= 0;
01225         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
01226 
01227         cbp = (cbpc & 3) | (cbpy << 2);
01228         if (dquant) {
01229             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
01230         }
01231         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
01232             s->interlaced_dct= get_bits1(&s->gb);
01233 
01234         s->mv_dir = MV_DIR_FORWARD;
01235         if ((cbpc & 16) == 0) {
01236             if(s->mcsel){
01237                 s->current_picture.mb_type[xy]= MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
01238                 /* 16x16 global motion prediction */
01239                 s->mv_type = MV_TYPE_16X16;
01240                 mx= get_amv(s, 0);
01241                 my= get_amv(s, 1);
01242                 s->mv[0][0][0] = mx;
01243                 s->mv[0][0][1] = my;
01244             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
01245                 s->current_picture.mb_type[xy]= MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
01246                 /* 16x8 field motion prediction */
01247                 s->mv_type= MV_TYPE_FIELD;
01248 
01249                 s->field_select[0][0]= get_bits1(&s->gb);
01250                 s->field_select[0][1]= get_bits1(&s->gb);
01251 
01252                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
01253 
01254                 for(i=0; i<2; i++){
01255                     mx = h263_decode_motion(s, pred_x, s->f_code);
01256                     if (mx >= 0xffff)
01257                         return -1;
01258 
01259                     my = h263_decode_motion(s, pred_y/2, s->f_code);
01260                     if (my >= 0xffff)
01261                         return -1;
01262 
01263                     s->mv[0][i][0] = mx;
01264                     s->mv[0][i][1] = my;
01265                 }
01266             }else{
01267                 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
01268                 /* 16x16 motion prediction */
01269                 s->mv_type = MV_TYPE_16X16;
01270                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
01271                 mx = h263_decode_motion(s, pred_x, s->f_code);
01272 
01273                 if (mx >= 0xffff)
01274                     return -1;
01275 
01276                 my = h263_decode_motion(s, pred_y, s->f_code);
01277 
01278                 if (my >= 0xffff)
01279                     return -1;
01280                 s->mv[0][0][0] = mx;
01281                 s->mv[0][0][1] = my;
01282             }
01283         } else {
01284             s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0;
01285             s->mv_type = MV_TYPE_8X8;
01286             for(i=0;i<4;i++) {
01287                 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
01288                 mx = h263_decode_motion(s, pred_x, s->f_code);
01289                 if (mx >= 0xffff)
01290                     return -1;
01291 
01292                 my = h263_decode_motion(s, pred_y, s->f_code);
01293                 if (my >= 0xffff)
01294                     return -1;
01295                 s->mv[0][i][0] = mx;
01296                 s->mv[0][i][1] = my;
01297                 mot_val[0] = mx;
01298                 mot_val[1] = my;
01299             }
01300         }
01301     } else if(s->pict_type==FF_B_TYPE) {
01302         int modb1; // first bit of modb
01303         int modb2; // second bit of modb
01304         int mb_type;
01305 
01306         s->mb_intra = 0; //B-frames never contain intra blocks
01307         s->mcsel=0;      //     ...               true gmc blocks
01308 
01309         if(s->mb_x==0){
01310             for(i=0; i<2; i++){
01311                 s->last_mv[i][0][0]=
01312                 s->last_mv[i][0][1]=
01313                 s->last_mv[i][1][0]=
01314                 s->last_mv[i][1][1]= 0;
01315             }
01316         }
01317 
01318         /* if we skipped it in the future P Frame than skip it now too */
01319         s->mb_skipped= s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
01320 
01321         if(s->mb_skipped){
01322                 /* skip mb */
01323             for(i=0;i<6;i++)
01324                 s->block_last_index[i] = -1;
01325 
01326             s->mv_dir = MV_DIR_FORWARD;
01327             s->mv_type = MV_TYPE_16X16;
01328             s->mv[0][0][0] = 0;
01329             s->mv[0][0][1] = 0;
01330             s->mv[1][0][0] = 0;
01331             s->mv[1][0][1] = 0;
01332             s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
01333             goto end;
01334         }
01335 
01336         modb1= get_bits1(&s->gb);
01337         if(modb1){
01338             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
01339             cbp=0;
01340         }else{
01341             modb2= get_bits1(&s->gb);
01342             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
01343             if(mb_type<0){
01344                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
01345                 return -1;
01346             }
01347             mb_type= mb_type_b_map[ mb_type ];
01348             if(modb2) cbp= 0;
01349             else{
01350                 s->dsp.clear_blocks(s->block[0]);
01351                 cbp= get_bits(&s->gb, 6);
01352             }
01353 
01354             if ((!IS_DIRECT(mb_type)) && cbp) {
01355                 if(get_bits1(&s->gb)){
01356                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
01357                 }
01358             }
01359 
01360             if(!s->progressive_sequence){
01361                 if(cbp)
01362                     s->interlaced_dct= get_bits1(&s->gb);
01363 
01364                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
01365                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
01366                     mb_type &= ~MB_TYPE_16x16;
01367 
01368                     if(USES_LIST(mb_type, 0)){
01369                         s->field_select[0][0]= get_bits1(&s->gb);
01370                         s->field_select[0][1]= get_bits1(&s->gb);
01371                     }
01372                     if(USES_LIST(mb_type, 1)){
01373                         s->field_select[1][0]= get_bits1(&s->gb);
01374                         s->field_select[1][1]= get_bits1(&s->gb);
01375                     }
01376                 }
01377             }
01378 
01379             s->mv_dir = 0;
01380             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
01381                 s->mv_type= MV_TYPE_16X16;
01382 
01383                 if(USES_LIST(mb_type, 0)){
01384                     s->mv_dir = MV_DIR_FORWARD;
01385 
01386                     mx = h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
01387                     my = h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
01388                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
01389                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
01390                 }
01391 
01392                 if(USES_LIST(mb_type, 1)){
01393                     s->mv_dir |= MV_DIR_BACKWARD;
01394 
01395                     mx = h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
01396                     my = h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
01397                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
01398                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
01399                 }
01400             }else if(!IS_DIRECT(mb_type)){
01401                 s->mv_type= MV_TYPE_FIELD;
01402 
01403                 if(USES_LIST(mb_type, 0)){
01404                     s->mv_dir = MV_DIR_FORWARD;
01405 
01406                     for(i=0; i<2; i++){
01407                         mx = h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
01408                         my = h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
01409                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
01410                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
01411                     }
01412                 }
01413 
01414                 if(USES_LIST(mb_type, 1)){
01415                     s->mv_dir |= MV_DIR_BACKWARD;
01416 
01417                     for(i=0; i<2; i++){
01418                         mx = h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
01419                         my = h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
01420                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
01421                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
01422                     }
01423                 }
01424             }
01425         }
01426 
01427         if(IS_DIRECT(mb_type)){
01428             if(IS_SKIP(mb_type))
01429                 mx=my=0;
01430             else{
01431                 mx = h263_decode_motion(s, 0, 1);
01432                 my = h263_decode_motion(s, 0, 1);
01433             }
01434 
01435             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
01436             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
01437         }
01438         s->current_picture.mb_type[xy]= mb_type;
01439     } else { /* I-Frame */
01440         do{
01441             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
01442             if (cbpc < 0){
01443                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
01444                 return -1;
01445             }
01446         }while(cbpc == 8);
01447 
01448         dquant = cbpc & 4;
01449         s->mb_intra = 1;
01450 intra:
01451         s->ac_pred = get_bits1(&s->gb);
01452         if(s->ac_pred)
01453             s->current_picture.mb_type[xy]= MB_TYPE_INTRA | MB_TYPE_ACPRED;
01454         else
01455             s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
01456 
01457         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
01458         if(cbpy<0){
01459             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
01460             return -1;
01461         }
01462         cbp = (cbpc & 3) | (cbpy << 2);
01463 
01464         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
01465 
01466         if (dquant) {
01467             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
01468         }
01469 
01470         if(!s->progressive_sequence)
01471             s->interlaced_dct= get_bits1(&s->gb);
01472 
01473         s->dsp.clear_blocks(s->block[0]);
01474         /* decode each block */
01475         for (i = 0; i < 6; i++) {
01476             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
01477                 return -1;
01478             cbp+=cbp;
01479         }
01480         goto end;
01481     }
01482 
01483     /* decode each block */
01484     for (i = 0; i < 6; i++) {
01485         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
01486             return -1;
01487         cbp+=cbp;
01488     }
01489 end:
01490 
01491         /* per-MB end of slice check */
01492     if(s->codec_id==CODEC_ID_MPEG4){
01493         if(mpeg4_is_resync(s)){
01494             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
01495             if(s->pict_type==FF_B_TYPE && s->next_picture.mbskip_table[xy + delta])
01496                 return SLICE_OK;
01497             return SLICE_END;
01498         }
01499     }
01500 
01501     return SLICE_OK;
01502 }
01503 
01504 
01505 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
01506     int hours, minutes, seconds;
01507 
01508     hours= get_bits(gb, 5);
01509     minutes= get_bits(gb, 6);
01510     skip_bits1(gb);
01511     seconds= get_bits(gb, 6);
01512 
01513     s->time_base= seconds + 60*(minutes + 60*hours);
01514 
01515     skip_bits1(gb);
01516     skip_bits1(gb);
01517 
01518     return 0;
01519 }
01520 
01521 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
01522     int width, height, vo_ver_id;
01523 
01524     /* vol header */
01525     skip_bits(gb, 1); /* random access */
01526     s->vo_type= get_bits(gb, 8);
01527     if (get_bits1(gb) != 0) { /* is_ol_id */
01528         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
01529         skip_bits(gb, 3); /* vo_priority */
01530     } else {
01531         vo_ver_id = 1;
01532     }
01533     s->aspect_ratio_info= get_bits(gb, 4);
01534     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
01535         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
01536         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
01537     }else{
01538         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
01539     }
01540 
01541     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
01542         int chroma_format= get_bits(gb, 2);
01543         if(chroma_format!=CHROMA_420){
01544             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
01545         }
01546         s->low_delay= get_bits1(gb);
01547         if(get_bits1(gb)){ /* vbv parameters */
01548             get_bits(gb, 15);   /* first_half_bitrate */
01549             skip_bits1(gb);     /* marker */
01550             get_bits(gb, 15);   /* latter_half_bitrate */
01551             skip_bits1(gb);     /* marker */
01552             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
01553             skip_bits1(gb);     /* marker */
01554             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
01555             get_bits(gb, 11);   /* first_half_vbv_occupancy */
01556             skip_bits1(gb);     /* marker */
01557             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
01558             skip_bits1(gb);     /* marker */
01559         }
01560     }else{
01561         // set low delay flag only once the smartest? low delay detection won't be overriden
01562         if(s->picture_number==0)
01563             s->low_delay=0;
01564     }
01565 
01566     s->shape = get_bits(gb, 2); /* vol shape */
01567     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
01568     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
01569         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
01570         skip_bits(gb, 4);  //video_object_layer_shape_extension
01571     }
01572 
01573     check_marker(gb, "before time_increment_resolution");
01574 
01575     s->avctx->time_base.den = get_bits(gb, 16);
01576     if(!s->avctx->time_base.den){
01577         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
01578         s->avctx->time_base.num = 0;
01579         return -1;
01580     }
01581 
01582     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
01583     if (s->time_increment_bits < 1)
01584         s->time_increment_bits = 1;
01585 
01586     check_marker(gb, "before fixed_vop_rate");
01587 
01588     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
01589         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
01590     }else
01591         s->avctx->time_base.num = 1;
01592 
01593     s->t_frame=0;
01594 
01595     if (s->shape != BIN_ONLY_SHAPE) {
01596         if (s->shape == RECT_SHAPE) {
01597             skip_bits1(gb);   /* marker */
01598             width = get_bits(gb, 13);
01599             skip_bits1(gb);   /* marker */
01600             height = get_bits(gb, 13);
01601             skip_bits1(gb);   /* marker */
01602             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
01603                 s->width = width;
01604                 s->height = height;
01605             }
01606         }
01607 
01608         s->progressive_sequence=
01609         s->progressive_frame= get_bits1(gb)^1;
01610         s->interlaced_dct=0;
01611         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
01612             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
01613         if (vo_ver_id == 1) {
01614             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
01615         } else {
01616             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
01617         }
01618         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
01619         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
01620             if(s->vol_sprite_usage==STATIC_SPRITE){
01621                 s->sprite_width = get_bits(gb, 13);
01622                 skip_bits1(gb); /* marker */
01623                 s->sprite_height= get_bits(gb, 13);
01624                 skip_bits1(gb); /* marker */
01625                 s->sprite_left  = get_bits(gb, 13);
01626                 skip_bits1(gb); /* marker */
01627                 s->sprite_top   = get_bits(gb, 13);
01628                 skip_bits1(gb); /* marker */
01629             }
01630             s->num_sprite_warping_points= get_bits(gb, 6);
01631             if(s->num_sprite_warping_points > 3){
01632                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
01633                 s->num_sprite_warping_points= 0;
01634                 return -1;
01635             }
01636             s->sprite_warping_accuracy = get_bits(gb, 2);
01637             s->sprite_brightness_change= get_bits1(gb);
01638             if(s->vol_sprite_usage==STATIC_SPRITE)
01639                 s->low_latency_sprite= get_bits1(gb);
01640         }
01641         // FIXME sadct disable bit if verid!=1 && shape not rect
01642 
01643         if (get_bits1(gb) == 1) {   /* not_8_bit */
01644             s->quant_precision = get_bits(gb, 4); /* quant_precision */
01645             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
01646             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
01647         } else {
01648             s->quant_precision = 5;
01649         }
01650 
01651         // FIXME a bunch of grayscale shape things
01652 
01653         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
01654             int i, v;
01655 
01656             /* load default matrixes */
01657             for(i=0; i<64; i++){
01658                 int j= s->dsp.idct_permutation[i];
01659                 v= ff_mpeg4_default_intra_matrix[i];
01660                 s->intra_matrix[j]= v;
01661                 s->chroma_intra_matrix[j]= v;
01662 
01663                 v= ff_mpeg4_default_non_intra_matrix[i];
01664                 s->inter_matrix[j]= v;
01665                 s->chroma_inter_matrix[j]= v;
01666             }
01667 
01668             /* load custom intra matrix */
01669             if(get_bits1(gb)){
01670                 int last=0;
01671                 for(i=0; i<64; i++){
01672                     int j;
01673                     v= get_bits(gb, 8);
01674                     if(v==0) break;
01675 
01676                     last= v;
01677                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01678                     s->intra_matrix[j]= v;
01679                     s->chroma_intra_matrix[j]= v;
01680                 }
01681 
01682                 /* replicate last value */
01683                 for(; i<64; i++){
01684                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01685                     s->intra_matrix[j]= last;
01686                     s->chroma_intra_matrix[j]= last;
01687                 }
01688             }
01689 
01690             /* load custom non intra matrix */
01691             if(get_bits1(gb)){
01692                 int last=0;
01693                 for(i=0; i<64; i++){
01694                     int j;
01695                     v= get_bits(gb, 8);
01696                     if(v==0) break;
01697 
01698                     last= v;
01699                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01700                     s->inter_matrix[j]= v;
01701                     s->chroma_inter_matrix[j]= v;
01702                 }
01703 
01704                 /* replicate last value */
01705                 for(; i<64; i++){
01706                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01707                     s->inter_matrix[j]= last;
01708                     s->chroma_inter_matrix[j]= last;
01709                 }
01710             }
01711 
01712             // FIXME a bunch of grayscale shape things
01713         }
01714 
01715         if(vo_ver_id != 1)
01716              s->quarter_sample= get_bits1(gb);
01717         else s->quarter_sample=0;
01718 
01719         if(!get_bits1(gb)){
01720             int pos= get_bits_count(gb);
01721             int estimation_method= get_bits(gb, 2);
01722             if(estimation_method<2){
01723                 if(!get_bits1(gb)){
01724                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
01725                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
01726                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
01727                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
01728                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
01729                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
01730                 }
01731                 if(!get_bits1(gb)){
01732                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
01733                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
01734                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
01735                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
01736                 }
01737                 if(!check_marker(gb, "in complexity estimation part 1")){
01738                     skip_bits_long(gb, pos - get_bits_count(gb));
01739                     goto no_cplx_est;
01740                 }
01741                 if(!get_bits1(gb)){
01742                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
01743                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
01744                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
01745                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
01746                 }
01747                 if(!get_bits1(gb)){
01748                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
01749                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
01750                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
01751                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
01752                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
01753                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
01754                 }
01755                 if(!check_marker(gb, "in complexity estimation part 2")){
01756                     skip_bits_long(gb, pos - get_bits_count(gb));
01757                     goto no_cplx_est;
01758                 }
01759                 if(estimation_method==1){
01760                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
01761                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
01762                 }
01763             }else
01764                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
01765         }else{
01766 no_cplx_est:
01767             s->cplx_estimation_trash_i=
01768             s->cplx_estimation_trash_p=
01769             s->cplx_estimation_trash_b= 0;
01770         }
01771 
01772         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
01773 
01774         s->data_partitioning= get_bits1(gb);
01775         if(s->data_partitioning){
01776             s->rvlc= get_bits1(gb);
01777         }
01778 
01779         if(vo_ver_id != 1) {
01780             s->new_pred= get_bits1(gb);
01781             if(s->new_pred){
01782                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
01783                 skip_bits(gb, 2); /* requested upstream message type */
01784                 skip_bits1(gb); /* newpred segment type */
01785             }
01786             s->reduced_res_vop= get_bits1(gb);
01787             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
01788         }
01789         else{
01790             s->new_pred=0;
01791             s->reduced_res_vop= 0;
01792         }
01793 
01794         s->scalability= get_bits1(gb);
01795 
01796         if (s->scalability) {
01797             GetBitContext bak= *gb;
01798             int ref_layer_id;
01799             int ref_layer_sampling_dir;
01800             int h_sampling_factor_n;
01801             int h_sampling_factor_m;
01802             int v_sampling_factor_n;
01803             int v_sampling_factor_m;
01804 
01805             s->hierachy_type= get_bits1(gb);
01806             ref_layer_id= get_bits(gb, 4);
01807             ref_layer_sampling_dir= get_bits1(gb);
01808             h_sampling_factor_n= get_bits(gb, 5);
01809             h_sampling_factor_m= get_bits(gb, 5);
01810             v_sampling_factor_n= get_bits(gb, 5);
01811             v_sampling_factor_m= get_bits(gb, 5);
01812             s->enhancement_type= get_bits1(gb);
01813 
01814             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
01815                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
01816                 /* illegal scalability header (VERY broken encoder),
01817                  * trying to workaround */
01818                 s->scalability=0;
01819                 *gb= bak;
01820             }else
01821                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
01822 
01823             // bin shape stuff FIXME
01824         }
01825     }
01826     return 0;
01827 }
01828 
01833 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
01834     char buf[256];
01835     int i;
01836     int e;
01837     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
01838     char last;
01839 
01840     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
01841         if(show_bits(gb, 23) == 0) break;
01842         buf[i]= get_bits(gb, 8);
01843     }
01844     buf[i]=0;
01845 
01846     /* divx detection */
01847     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
01848     if(e<2)
01849         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
01850     if(e>=2){
01851         s->divx_version= ver;
01852         s->divx_build= build;
01853         s->divx_packed= e==3 && last=='p';
01854         if(s->divx_packed && !s->showed_packed_warning) {
01855             av_log(s->avctx, AV_LOG_WARNING, "Invalid and inefficient vfw-avi packed B frames detected\n");
01856             s->showed_packed_warning=1;
01857         }
01858     }
01859 
01860     /* ffmpeg detection */
01861     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
01862     if(e!=4)
01863         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
01864     if(e!=4){
01865         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
01866         if (e>1)
01867             build= (ver<<16) + (ver2<<8) + ver3;
01868     }
01869     if(e!=4){
01870         if(strcmp(buf, "ffmpeg")==0){
01871             s->lavc_build= 4600;
01872         }
01873     }
01874     if(e==4){
01875         s->lavc_build= build;
01876     }
01877 
01878     /* Xvid detection */
01879     e=sscanf(buf, "XviD%d", &build);
01880     if(e==1){
01881         s->xvid_build= build;
01882     }
01883 
01884     return 0;
01885 }
01886 
01887 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
01888     int time_incr, time_increment;
01889 
01890     s->pict_type = get_bits(gb, 2) + FF_I_TYPE;        /* pict type: I = 0 , P = 1 */
01891     if(s->pict_type==FF_B_TYPE && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
01892         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
01893         s->low_delay=0;
01894     }
01895 
01896     s->partitioned_frame= s->data_partitioning && s->pict_type!=FF_B_TYPE;
01897     if(s->partitioned_frame)
01898         s->decode_mb= mpeg4_decode_partitioned_mb;
01899     else
01900         s->decode_mb= mpeg4_decode_mb;
01901 
01902     time_incr=0;
01903     while (get_bits1(gb) != 0)
01904         time_incr++;
01905 
01906     check_marker(gb, "before time_increment");
01907 
01908     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
01909         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
01910 
01911         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
01912             if (    s->pict_type == FF_P_TYPE
01913                 || (s->pict_type == FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE)) {
01914                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
01915             }else
01916                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
01917         }
01918 
01919         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
01920     }
01921 
01922     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
01923     else time_increment= get_bits(gb, s->time_increment_bits);
01924 
01925     if(s->pict_type!=FF_B_TYPE){
01926         s->last_time_base= s->time_base;
01927         s->time_base+= time_incr;
01928         s->time= s->time_base*s->avctx->time_base.den + time_increment;
01929         if(s->workaround_bugs&FF_BUG_UMP4){
01930             if(s->time < s->last_non_b_time){
01931                 /* header is not mpeg-4-compatible, broken encoder,
01932                  * trying to workaround */
01933                 s->time_base++;
01934                 s->time+= s->avctx->time_base.den;
01935             }
01936         }
01937         s->pp_time= s->time - s->last_non_b_time;
01938         s->last_non_b_time= s->time;
01939     }else{
01940         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
01941         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
01942         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
01943             /* messed up order, maybe after seeking? skipping current b-frame */
01944             return FRAME_SKIPPED;
01945         }
01946         ff_mpeg4_init_direct_mv(s);
01947 
01948         if(s->t_frame==0) s->t_frame= s->pb_time;
01949         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
01950         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
01951                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
01952         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
01953                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
01954         if(!s->progressive_sequence){
01955             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
01956                 return FRAME_SKIPPED;
01957         }
01958     }
01959 
01960     if(s->avctx->time_base.num)
01961         s->current_picture_ptr->pts= (s->time + s->avctx->time_base.num/2) / s->avctx->time_base.num;
01962     else
01963         s->current_picture_ptr->pts= AV_NOPTS_VALUE;
01964     if(s->avctx->debug&FF_DEBUG_PTS)
01965         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n", s->current_picture_ptr->pts);
01966 
01967     check_marker(gb, "before vop_coded");
01968 
01969     /* vop coded */
01970     if (get_bits1(gb) != 1){
01971         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
01972             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
01973         return FRAME_SKIPPED;
01974     }
01975     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == FF_P_TYPE
01976                           || (s->pict_type == FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE))) {
01977         /* rounding type for motion estimation */
01978         s->no_rounding = get_bits1(gb);
01979     } else {
01980         s->no_rounding = 0;
01981     }
01982 //FIXME reduced res stuff
01983 
01984      if (s->shape != RECT_SHAPE) {
01985          if (s->vol_sprite_usage != 1 || s->pict_type != FF_I_TYPE) {
01986              int width, height, hor_spat_ref, ver_spat_ref;
01987 
01988              width = get_bits(gb, 13);
01989              skip_bits1(gb);   /* marker */
01990              height = get_bits(gb, 13);
01991              skip_bits1(gb);   /* marker */
01992              hor_spat_ref = get_bits(gb, 13); /* hor_spat_ref */
01993              skip_bits1(gb);   /* marker */
01994              ver_spat_ref = get_bits(gb, 13); /* ver_spat_ref */
01995          }
01996          skip_bits1(gb); /* change_CR_disable */
01997 
01998          if (get_bits1(gb) != 0) {
01999              skip_bits(gb, 8); /* constant_alpha_value */
02000          }
02001      }
02002 //FIXME complexity estimation stuff
02003 
02004      if (s->shape != BIN_ONLY_SHAPE) {
02005          skip_bits_long(gb, s->cplx_estimation_trash_i);
02006          if(s->pict_type != FF_I_TYPE)
02007             skip_bits_long(gb, s->cplx_estimation_trash_p);
02008          if(s->pict_type == FF_B_TYPE)
02009             skip_bits_long(gb, s->cplx_estimation_trash_b);
02010 
02011          s->intra_dc_threshold= mpeg4_dc_threshold[ get_bits(gb, 3) ];
02012          if(!s->progressive_sequence){
02013              s->top_field_first= get_bits1(gb);
02014              s->alternate_scan= get_bits1(gb);
02015          }else
02016              s->alternate_scan= 0;
02017      }
02018 
02019      if(s->alternate_scan){
02020          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
02021          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
02022          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
02023          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
02024      } else{
02025          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
02026          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
02027          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
02028          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
02029      }
02030 
02031      if(s->pict_type == FF_S_TYPE && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
02032          mpeg4_decode_sprite_trajectory(s, gb);
02033          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
02034          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
02035      }
02036 
02037      if (s->shape != BIN_ONLY_SHAPE) {
02038          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
02039          if(s->qscale==0){
02040              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
02041              return -1; // makes no sense to continue, as there is nothing left from the image then
02042          }
02043 
02044          if (s->pict_type != FF_I_TYPE) {
02045              s->f_code = get_bits(gb, 3);       /* fcode_for */
02046              if(s->f_code==0){
02047                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
02048                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
02049              }
02050          }else
02051              s->f_code=1;
02052 
02053          if (s->pict_type == FF_B_TYPE) {
02054              s->b_code = get_bits(gb, 3);
02055          }else
02056              s->b_code=1;
02057 
02058          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
02059              av_log(s->avctx, AV_LOG_DEBUG, "qp:%d fc:%d,%d %s size:%d pro:%d alt:%d top:%d %spel part:%d resync:%d w:%d a:%d rnd:%d vot:%d%s dc:%d ce:%d/%d/%d\n",
02060                  s->qscale, s->f_code, s->b_code,
02061                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
02062                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
02063                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
02064                  s->sprite_warping_accuracy, 1-s->no_rounding, s->vo_type, s->vol_control_parameters ? " VOLC" : " ", s->intra_dc_threshold, s->cplx_estimation_trash_i, s->cplx_estimation_trash_p, s->cplx_estimation_trash_b);
02065          }
02066 
02067          if(!s->scalability){
02068              if (s->shape!=RECT_SHAPE && s->pict_type!=FF_I_TYPE) {
02069                  skip_bits1(gb); // vop shape coding type
02070              }
02071          }else{
02072              if(s->enhancement_type){
02073                  int load_backward_shape= get_bits1(gb);
02074                  if(load_backward_shape){
02075                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
02076                  }
02077              }
02078              skip_bits(gb, 2); //ref_select_code
02079          }
02080      }
02081      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
02082      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
02083      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
02084          av_log(s->avctx, AV_LOG_ERROR, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
02085          s->low_delay=1;
02086      }
02087 
02088      s->picture_number++; // better than pic number==0 always ;)
02089 
02090      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
02091      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
02092 
02093      if(s->workaround_bugs&FF_BUG_EDGE){
02094          s->h_edge_pos= s->width;
02095          s->v_edge_pos= s->height;
02096      }
02097      return 0;
02098 }
02099 
02106 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
02107 {
02108     int startcode, v;
02109 
02110     /* search next start code */
02111     align_get_bits(gb);
02112 
02113     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
02114         skip_bits(gb, 24);
02115         if(get_bits(gb, 8) == 0xF0)
02116             goto end;
02117     }
02118 
02119     startcode = 0xff;
02120     for(;;) {
02121         if(get_bits_count(gb) >= gb->size_in_bits){
02122             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0)){
02123                 av_log(s->avctx, AV_LOG_ERROR, "frame skip %d\n", gb->size_in_bits);
02124                 return FRAME_SKIPPED; //divx bug
02125             }else
02126                 return -1; //end of stream
02127         }
02128 
02129         /* use the bits after the test */
02130         v = get_bits(gb, 8);
02131         startcode = ((startcode << 8) | v) & 0xffffffff;
02132 
02133         if((startcode&0xFFFFFF00) != 0x100)
02134             continue; //no startcode
02135 
02136         if(s->avctx->debug&FF_DEBUG_STARTCODE){
02137             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
02138             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
02139             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
02140             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
02141             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
02142             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
02143             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
02144             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
02145             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
02146             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
02147             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
02148             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
02149             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
02150             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
02151             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
02152             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
02153             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
02154             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
02155             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
02156             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
02157             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
02158             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
02159             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
02160             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
02161             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
02162             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
02163             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
02164             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
02165             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
02166         }
02167 
02168         if(startcode >= 0x120 && startcode <= 0x12F){
02169             if(decode_vol_header(s, gb) < 0)
02170                 return -1;
02171         }
02172         else if(startcode == USER_DATA_STARTCODE){
02173             decode_user_data(s, gb);
02174         }
02175         else if(startcode == GOP_STARTCODE){
02176             mpeg4_decode_gop_header(s, gb);
02177         }
02178         else if(startcode == VOP_STARTCODE){
02179             break;
02180         }
02181 
02182         align_get_bits(gb);
02183         startcode = 0xff;
02184     }
02185 end:
02186     if(s->flags& CODEC_FLAG_LOW_DELAY)
02187         s->low_delay=1;
02188     s->avctx->has_b_frames= !s->low_delay;
02189     return decode_vop_header(s, gb);
02190 }
02191 
02192 static av_cold int decode_init(AVCodecContext *avctx)
02193 {
02194     MpegEncContext *s = avctx->priv_data;
02195     int ret;
02196     static int done = 0;
02197 
02198     s->divx_version=
02199     s->divx_build=
02200     s->xvid_build=
02201     s->lavc_build= -1;
02202 
02203     if((ret=ff_h263_decode_init(avctx)) < 0)
02204         return ret;
02205 
02206     if (!done) {
02207         done = 1;
02208 
02209         init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
02210         init_rl(&rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
02211         init_rl(&rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
02212         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
02213         INIT_VLC_RL(rvlc_rl_inter, 1072);
02214         INIT_VLC_RL(rvlc_rl_intra, 1072);
02215         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
02216                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
02217                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
02218         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
02219                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
02220                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
02221         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
02222                  &sprite_trajectory_tab[0][1], 4, 2,
02223                  &sprite_trajectory_tab[0][0], 4, 2, 128);
02224         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
02225                  &mb_type_b_tab[0][1], 2, 1,
02226                  &mb_type_b_tab[0][0], 2, 1, 16);
02227     }
02228 
02229     s->h263_pred = 1;
02230     s->low_delay = 0; //default, might be overriden in the vol header during header parsing
02231     s->decode_mb= mpeg4_decode_mb;
02232     s->time_increment_bits = 4; /* default value for broken headers */
02233     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
02234 
02235     return 0;
02236 }
02237 
02238 AVCodec mpeg4_decoder = {
02239     "mpeg4",
02240     AVMEDIA_TYPE_VIDEO,
02241     CODEC_ID_MPEG4,
02242     sizeof(MpegEncContext),
02243     decode_init,
02244     NULL,
02245     ff_h263_decode_end,
02246     ff_h263_decode_frame,
02247     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY,
02248     .flush= ff_mpeg_flush,
02249     .max_lowres= 3,
02250     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
02251     .pix_fmts= ff_hwaccel_pixfmt_list_420,
02252 };
02253 
02254 
02255 #if CONFIG_MPEG4_VDPAU_DECODER
02256 AVCodec mpeg4_vdpau_decoder = {
02257     "mpeg4_vdpau",
02258     AVMEDIA_TYPE_VIDEO,
02259     CODEC_ID_MPEG4,
02260     sizeof(MpegEncContext),
02261     decode_init,
02262     NULL,
02263     ff_h263_decode_end,
02264     ff_h263_decode_frame,
02265     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_HWACCEL_VDPAU,
02266     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
02267     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_VDPAU_MPEG4, PIX_FMT_NONE},
02268 };
02269 #endif