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 #include "thread.h"
00027 
00028 // The defines below define the number of bits that are read at once for
00029 // reading vlc values. Changing these may improve speed and data cache needs
00030 // be aware though that decreasing them may need the number of stages that is
00031 // passed to get_vlc* to be increased.
00032 #define SPRITE_TRAJ_VLC_BITS 6
00033 #define DC_VLC_BITS 9
00034 #define MB_TYPE_B_VLC_BITS 4
00035 
00036 
00037 static VLC dc_lum, dc_chrom;
00038 static VLC sprite_trajectory;
00039 static VLC mb_type_b_vlc;
00040 
00041 static const int mb_type_b_map[4]= {
00042     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
00043     MB_TYPE_L0L1 | MB_TYPE_16x16,
00044     MB_TYPE_L1 | MB_TYPE_16x16,
00045     MB_TYPE_L0 | MB_TYPE_16x16,
00046 };
00047 
00053 void mpeg4_pred_ac(MpegEncContext * s, DCTELEM *block, int n,
00054                    int dir)
00055 {
00056     int i;
00057     int16_t *ac_val, *ac_val1;
00058     int8_t * const qscale_table= s->current_picture.qscale_table;
00059 
00060     /* find prediction */
00061     ac_val = s->ac_val[0][0] + s->block_index[n] * 16;
00062     ac_val1 = ac_val;
00063     if (s->ac_pred) {
00064         if (dir == 0) {
00065             const int xy= s->mb_x-1 + s->mb_y*s->mb_stride;
00066             /* left prediction */
00067             ac_val -= 16;
00068 
00069             if(s->mb_x==0 || s->qscale == qscale_table[xy] || n==1 || n==3){
00070                 /* same qscale */
00071                 for(i=1;i<8;i++) {
00072                     block[s->dsp.idct_permutation[i<<3]] += ac_val[i];
00073                 }
00074             }else{
00075                 /* different qscale, we must rescale */
00076                 for(i=1;i<8;i++) {
00077                     block[s->dsp.idct_permutation[i<<3]] += ROUNDED_DIV(ac_val[i]*qscale_table[xy], s->qscale);
00078                 }
00079             }
00080         } else {
00081             const int xy= s->mb_x + s->mb_y*s->mb_stride - s->mb_stride;
00082             /* top prediction */
00083             ac_val -= 16 * s->block_wrap[n];
00084 
00085             if(s->mb_y==0 || s->qscale == qscale_table[xy] || n==2 || n==3){
00086                 /* same qscale */
00087                 for(i=1;i<8;i++) {
00088                     block[s->dsp.idct_permutation[i]] += ac_val[i + 8];
00089                 }
00090             }else{
00091                 /* different qscale, we must rescale */
00092                 for(i=1;i<8;i++) {
00093                     block[s->dsp.idct_permutation[i]] += ROUNDED_DIV(ac_val[i + 8]*qscale_table[xy], s->qscale);
00094                 }
00095             }
00096         }
00097     }
00098     /* left copy */
00099     for(i=1;i<8;i++)
00100         ac_val1[i    ] = block[s->dsp.idct_permutation[i<<3]];
00101 
00102     /* top copy */
00103     for(i=1;i<8;i++)
00104         ac_val1[8 + i] = block[s->dsp.idct_permutation[i   ]];
00105 
00106 }
00107 
00112 static inline int mpeg4_is_resync(MpegEncContext *s){
00113     int bits_count= get_bits_count(&s->gb);
00114     int v= show_bits(&s->gb, 16);
00115 
00116     if(s->workaround_bugs&FF_BUG_NO_PADDING){
00117         return 0;
00118     }
00119 
00120     while(v<=0xFF){
00121         if(s->pict_type==FF_B_TYPE || (v>>(8-s->pict_type)!=1) || s->partitioned_frame)
00122             break;
00123         skip_bits(&s->gb, 8+s->pict_type);
00124         bits_count+= 8+s->pict_type;
00125         v= show_bits(&s->gb, 16);
00126     }
00127 
00128     if(bits_count + 8 >= s->gb.size_in_bits){
00129         v>>=8;
00130         v|= 0x7F >> (7-(bits_count&7));
00131 
00132         if(v==0x7F)
00133             return 1;
00134     }else{
00135         if(v == ff_mpeg4_resync_prefix[bits_count&7]){
00136             int len;
00137             GetBitContext gb= s->gb;
00138 
00139             skip_bits(&s->gb, 1);
00140             align_get_bits(&s->gb);
00141 
00142             for(len=0; len<32; len++){
00143                 if(get_bits1(&s->gb)) break;
00144             }
00145 
00146             s->gb= gb;
00147 
00148             if(len>=ff_mpeg4_get_video_packet_prefix_length(s))
00149                 return 1;
00150         }
00151     }
00152     return 0;
00153 }
00154 
00155 static void mpeg4_decode_sprite_trajectory(MpegEncContext * s, GetBitContext *gb)
00156 {
00157     int i;
00158     int a= 2<<s->sprite_warping_accuracy;
00159     int rho= 3-s->sprite_warping_accuracy;
00160     int r=16/a;
00161     const int vop_ref[4][2]= {{0,0}, {s->width,0}, {0, s->height}, {s->width, s->height}}; // only true for rectangle shapes
00162     int d[4][2]={{0,0}, {0,0}, {0,0}, {0,0}};
00163     int sprite_ref[4][2];
00164     int virtual_ref[2][2];
00165     int w2, h2, w3, h3;
00166     int alpha=0, beta=0;
00167     int w= s->width;
00168     int h= s->height;
00169     int min_ab;
00170 
00171     for(i=0; i<s->num_sprite_warping_points; i++){
00172         int length;
00173         int x=0, y=0;
00174 
00175         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
00176         if(length){
00177             x= get_xbits(gb, length);
00178         }
00179         if(!(s->divx_version==500 && s->divx_build==413)) skip_bits1(gb); /* marker bit */
00180 
00181         length= get_vlc2(gb, sprite_trajectory.table, SPRITE_TRAJ_VLC_BITS, 3);
00182         if(length){
00183             y=get_xbits(gb, length);
00184         }
00185         skip_bits1(gb); /* marker bit */
00186         s->sprite_traj[i][0]= d[i][0]= x;
00187         s->sprite_traj[i][1]= d[i][1]= y;
00188     }
00189     for(; i<4; i++)
00190         s->sprite_traj[i][0]= s->sprite_traj[i][1]= 0;
00191 
00192     while((1<<alpha)<w) alpha++;
00193     while((1<<beta )<h) beta++; // there seems to be a typo in the mpeg4 std for the definition of w' and h'
00194     w2= 1<<alpha;
00195     h2= 1<<beta;
00196 
00197 // Note, the 4th point isn't used for GMC
00198     if(s->divx_version==500 && s->divx_build==413){
00199         sprite_ref[0][0]= a*vop_ref[0][0] + d[0][0];
00200         sprite_ref[0][1]= a*vop_ref[0][1] + d[0][1];
00201         sprite_ref[1][0]= a*vop_ref[1][0] + d[0][0] + d[1][0];
00202         sprite_ref[1][1]= a*vop_ref[1][1] + d[0][1] + d[1][1];
00203         sprite_ref[2][0]= a*vop_ref[2][0] + d[0][0] + d[2][0];
00204         sprite_ref[2][1]= a*vop_ref[2][1] + d[0][1] + d[2][1];
00205     } else {
00206         sprite_ref[0][0]= (a>>1)*(2*vop_ref[0][0] + d[0][0]);
00207         sprite_ref[0][1]= (a>>1)*(2*vop_ref[0][1] + d[0][1]);
00208         sprite_ref[1][0]= (a>>1)*(2*vop_ref[1][0] + d[0][0] + d[1][0]);
00209         sprite_ref[1][1]= (a>>1)*(2*vop_ref[1][1] + d[0][1] + d[1][1]);
00210         sprite_ref[2][0]= (a>>1)*(2*vop_ref[2][0] + d[0][0] + d[2][0]);
00211         sprite_ref[2][1]= (a>>1)*(2*vop_ref[2][1] + d[0][1] + d[2][1]);
00212     }
00213 /*    sprite_ref[3][0]= (a>>1)*(2*vop_ref[3][0] + d[0][0] + d[1][0] + d[2][0] + d[3][0]);
00214     sprite_ref[3][1]= (a>>1)*(2*vop_ref[3][1] + d[0][1] + d[1][1] + d[2][1] + d[3][1]); */
00215 
00216 // this is mostly identical to the mpeg4 std (and is totally unreadable because of that ...)
00217 // perhaps it should be reordered to be more readable ...
00218 // the idea behind this virtual_ref mess is to be able to use shifts later per pixel instead of divides
00219 // so the distance between points is converted from w&h based to w2&h2 based which are of the 2^x form
00220     virtual_ref[0][0]= 16*(vop_ref[0][0] + w2)
00221         + 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);
00222     virtual_ref[0][1]= 16*vop_ref[0][1]
00223         + 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);
00224     virtual_ref[1][0]= 16*vop_ref[0][0]
00225         + 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);
00226     virtual_ref[1][1]= 16*(vop_ref[0][1] + h2)
00227         + 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);
00228 
00229     switch(s->num_sprite_warping_points)
00230     {
00231         case 0:
00232             s->sprite_offset[0][0]= 0;
00233             s->sprite_offset[0][1]= 0;
00234             s->sprite_offset[1][0]= 0;
00235             s->sprite_offset[1][1]= 0;
00236             s->sprite_delta[0][0]= a;
00237             s->sprite_delta[0][1]= 0;
00238             s->sprite_delta[1][0]= 0;
00239             s->sprite_delta[1][1]= a;
00240             s->sprite_shift[0]= 0;
00241             s->sprite_shift[1]= 0;
00242             break;
00243         case 1: //GMC only
00244             s->sprite_offset[0][0]= sprite_ref[0][0] - a*vop_ref[0][0];
00245             s->sprite_offset[0][1]= sprite_ref[0][1] - a*vop_ref[0][1];
00246             s->sprite_offset[1][0]= ((sprite_ref[0][0]>>1)|(sprite_ref[0][0]&1)) - a*(vop_ref[0][0]/2);
00247             s->sprite_offset[1][1]= ((sprite_ref[0][1]>>1)|(sprite_ref[0][1]&1)) - a*(vop_ref[0][1]/2);
00248             s->sprite_delta[0][0]= a;
00249             s->sprite_delta[0][1]= 0;
00250             s->sprite_delta[1][0]= 0;
00251             s->sprite_delta[1][1]= a;
00252             s->sprite_shift[0]= 0;
00253             s->sprite_shift[1]= 0;
00254             break;
00255         case 2:
00256             s->sprite_offset[0][0]= (sprite_ref[0][0]<<(alpha+rho))
00257                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][0])
00258                                                   + ( r*sprite_ref[0][1] - virtual_ref[0][1])*(-vop_ref[0][1])
00259                                                   + (1<<(alpha+rho-1));
00260             s->sprite_offset[0][1]= (sprite_ref[0][1]<<(alpha+rho))
00261                                                   + (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-vop_ref[0][0])
00262                                                   + (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-vop_ref[0][1])
00263                                                   + (1<<(alpha+rho-1));
00264             s->sprite_offset[1][0]= ( (-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][0] + 1)
00265                                      +( r*sprite_ref[0][1] - virtual_ref[0][1])*(-2*vop_ref[0][1] + 1)
00266                                      +2*w2*r*sprite_ref[0][0]
00267                                      - 16*w2
00268                                      + (1<<(alpha+rho+1)));
00269             s->sprite_offset[1][1]= ( (-r*sprite_ref[0][1] + virtual_ref[0][1])*(-2*vop_ref[0][0] + 1)
00270                                      +(-r*sprite_ref[0][0] + virtual_ref[0][0])*(-2*vop_ref[0][1] + 1)
00271                                      +2*w2*r*sprite_ref[0][1]
00272                                      - 16*w2
00273                                      + (1<<(alpha+rho+1)));
00274             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
00275             s->sprite_delta[0][1]=   (+r*sprite_ref[0][1] - virtual_ref[0][1]);
00276             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1]);
00277             s->sprite_delta[1][1]=   (-r*sprite_ref[0][0] + virtual_ref[0][0]);
00278 
00279             s->sprite_shift[0]= alpha+rho;
00280             s->sprite_shift[1]= alpha+rho+2;
00281             break;
00282         case 3:
00283             min_ab= FFMIN(alpha, beta);
00284             w3= w2>>min_ab;
00285             h3= h2>>min_ab;
00286             s->sprite_offset[0][0]=  (sprite_ref[0][0]<<(alpha+beta+rho-min_ab))
00287                                    + (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-vop_ref[0][0])
00288                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-vop_ref[0][1])
00289                                    + (1<<(alpha+beta+rho-min_ab-1));
00290             s->sprite_offset[0][1]=  (sprite_ref[0][1]<<(alpha+beta+rho-min_ab))
00291                                    + (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-vop_ref[0][0])
00292                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-vop_ref[0][1])
00293                                    + (1<<(alpha+beta+rho-min_ab-1));
00294             s->sprite_offset[1][0]=  (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3*(-2*vop_ref[0][0] + 1)
00295                                    + (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3*(-2*vop_ref[0][1] + 1)
00296                                    + 2*w2*h3*r*sprite_ref[0][0]
00297                                    - 16*w2*h3
00298                                    + (1<<(alpha+beta+rho-min_ab+1));
00299             s->sprite_offset[1][1]=  (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3*(-2*vop_ref[0][0] + 1)
00300                                    + (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3*(-2*vop_ref[0][1] + 1)
00301                                    + 2*w2*h3*r*sprite_ref[0][1]
00302                                    - 16*w2*h3
00303                                    + (1<<(alpha+beta+rho-min_ab+1));
00304             s->sprite_delta[0][0]=   (-r*sprite_ref[0][0] + virtual_ref[0][0])*h3;
00305             s->sprite_delta[0][1]=   (-r*sprite_ref[0][0] + virtual_ref[1][0])*w3;
00306             s->sprite_delta[1][0]=   (-r*sprite_ref[0][1] + virtual_ref[0][1])*h3;
00307             s->sprite_delta[1][1]=   (-r*sprite_ref[0][1] + virtual_ref[1][1])*w3;
00308 
00309             s->sprite_shift[0]= alpha + beta + rho - min_ab;
00310             s->sprite_shift[1]= alpha + beta + rho - min_ab + 2;
00311             break;
00312     }
00313     /* try to simplify the situation */
00314     if(   s->sprite_delta[0][0] == a<<s->sprite_shift[0]
00315        && s->sprite_delta[0][1] == 0
00316        && s->sprite_delta[1][0] == 0
00317        && s->sprite_delta[1][1] == a<<s->sprite_shift[0])
00318     {
00319         s->sprite_offset[0][0]>>=s->sprite_shift[0];
00320         s->sprite_offset[0][1]>>=s->sprite_shift[0];
00321         s->sprite_offset[1][0]>>=s->sprite_shift[1];
00322         s->sprite_offset[1][1]>>=s->sprite_shift[1];
00323         s->sprite_delta[0][0]= a;
00324         s->sprite_delta[0][1]= 0;
00325         s->sprite_delta[1][0]= 0;
00326         s->sprite_delta[1][1]= a;
00327         s->sprite_shift[0]= 0;
00328         s->sprite_shift[1]= 0;
00329         s->real_sprite_warping_points=1;
00330     }
00331     else{
00332         int shift_y= 16 - s->sprite_shift[0];
00333         int shift_c= 16 - s->sprite_shift[1];
00334         for(i=0; i<2; i++){
00335             s->sprite_offset[0][i]<<= shift_y;
00336             s->sprite_offset[1][i]<<= shift_c;
00337             s->sprite_delta[0][i]<<= shift_y;
00338             s->sprite_delta[1][i]<<= shift_y;
00339             s->sprite_shift[i]= 16;
00340         }
00341         s->real_sprite_warping_points= s->num_sprite_warping_points;
00342     }
00343 }
00344 
00349 int mpeg4_decode_video_packet_header(MpegEncContext *s)
00350 {
00351     int mb_num_bits= av_log2(s->mb_num - 1) + 1;
00352     int header_extension=0, mb_num, len;
00353 
00354     /* is there enough space left for a video packet + header */
00355     if( get_bits_count(&s->gb) > s->gb.size_in_bits-20) return -1;
00356 
00357     for(len=0; len<32; len++){
00358         if(get_bits1(&s->gb)) break;
00359     }
00360 
00361     if(len!=ff_mpeg4_get_video_packet_prefix_length(s)){
00362         av_log(s->avctx, AV_LOG_ERROR, "marker does not match f_code\n");
00363         return -1;
00364     }
00365 
00366     if(s->shape != RECT_SHAPE){
00367         header_extension= get_bits1(&s->gb);
00368         //FIXME more stuff here
00369     }
00370 
00371     mb_num= get_bits(&s->gb, mb_num_bits);
00372     if(mb_num>=s->mb_num){
00373         av_log(s->avctx, AV_LOG_ERROR, "illegal mb_num in video packet (%d %d) \n", mb_num, s->mb_num);
00374         return -1;
00375     }
00376     if(s->pict_type == FF_B_TYPE){
00377         int mb_x = 0, mb_y = 0;
00378 
00379         while(s->next_picture.mbskip_table[ s->mb_index2xy[ mb_num ] ]) {
00380             if (!mb_x) ff_thread_await_progress((AVFrame*)s->next_picture_ptr, mb_y++, 0);
00381             mb_num++;
00382             if (++mb_x == s->mb_width) mb_x = 0;
00383         }
00384         if(mb_num >= s->mb_num) return -1; // slice contains just skipped MBs which where already decoded
00385     }
00386 
00387     s->mb_x= mb_num % s->mb_width;
00388     s->mb_y= mb_num / s->mb_width;
00389 
00390     if(s->shape != BIN_ONLY_SHAPE){
00391         int qscale= get_bits(&s->gb, s->quant_precision);
00392         if(qscale)
00393             s->chroma_qscale=s->qscale= qscale;
00394     }
00395 
00396     if(s->shape == RECT_SHAPE){
00397         header_extension= get_bits1(&s->gb);
00398     }
00399     if(header_extension){
00400         int time_increment;
00401         int time_incr=0;
00402 
00403         while (get_bits1(&s->gb) != 0)
00404             time_incr++;
00405 
00406         check_marker(&s->gb, "before time_increment in video packed header");
00407         time_increment= get_bits(&s->gb, s->time_increment_bits);
00408         check_marker(&s->gb, "before vop_coding_type in video packed header");
00409 
00410         skip_bits(&s->gb, 2); /* vop coding type */
00411         //FIXME not rect stuff here
00412 
00413         if(s->shape != BIN_ONLY_SHAPE){
00414             skip_bits(&s->gb, 3); /* intra dc vlc threshold */
00415 //FIXME don't just ignore everything
00416             if(s->pict_type == FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
00417                 mpeg4_decode_sprite_trajectory(s, &s->gb);
00418                 av_log(s->avctx, AV_LOG_ERROR, "untested\n");
00419             }
00420 
00421             //FIXME reduced res stuff here
00422 
00423             if (s->pict_type != FF_I_TYPE) {
00424                 int f_code = get_bits(&s->gb, 3);       /* fcode_for */
00425                 if(f_code==0){
00426                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (f_code=0)\n");
00427                 }
00428             }
00429             if (s->pict_type == FF_B_TYPE) {
00430                 int b_code = get_bits(&s->gb, 3);
00431                 if(b_code==0){
00432                     av_log(s->avctx, AV_LOG_ERROR, "Error, video packet header damaged (b_code=0)\n");
00433                 }
00434             }
00435         }
00436     }
00437     //FIXME new-pred stuff
00438 
00439     return 0;
00440 }
00441 
00447 static inline int get_amv(MpegEncContext *s, int n){
00448     int x, y, mb_v, sum, dx, dy, shift;
00449     int len = 1 << (s->f_code + 4);
00450     const int a= s->sprite_warping_accuracy;
00451 
00452     if(s->workaround_bugs & FF_BUG_AMV)
00453         len >>= s->quarter_sample;
00454 
00455     if(s->real_sprite_warping_points==1){
00456         if(s->divx_version==500 && s->divx_build==413)
00457             sum= s->sprite_offset[0][n] / (1<<(a - s->quarter_sample));
00458         else
00459             sum= RSHIFT(s->sprite_offset[0][n]<<s->quarter_sample, a);
00460     }else{
00461         dx= s->sprite_delta[n][0];
00462         dy= s->sprite_delta[n][1];
00463         shift= s->sprite_shift[0];
00464         if(n) dy -= 1<<(shift + a + 1);
00465         else  dx -= 1<<(shift + a + 1);
00466         mb_v= s->sprite_offset[0][n] + dx*s->mb_x*16 + dy*s->mb_y*16;
00467 
00468         sum=0;
00469         for(y=0; y<16; y++){
00470             int v;
00471 
00472             v= mb_v + dy*y;
00473             //XXX FIXME optimize
00474             for(x=0; x<16; x++){
00475                 sum+= v>>shift;
00476                 v+= dx;
00477             }
00478         }
00479         sum= RSHIFT(sum, a+8-s->quarter_sample);
00480     }
00481 
00482     if      (sum < -len) sum= -len;
00483     else if (sum >= len) sum= len-1;
00484 
00485     return sum;
00486 }
00487 
00494 static inline int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
00495 {
00496     int level, code;
00497 
00498     if (n < 4)
00499         code = get_vlc2(&s->gb, dc_lum.table, DC_VLC_BITS, 1);
00500     else
00501         code = get_vlc2(&s->gb, dc_chrom.table, DC_VLC_BITS, 1);
00502     if (code < 0 || code > 9 /* && s->nbit<9 */){
00503         av_log(s->avctx, AV_LOG_ERROR, "illegal dc vlc\n");
00504         return -1;
00505     }
00506     if (code == 0) {
00507         level = 0;
00508     } else {
00509         if(IS_3IV1){
00510             if(code==1)
00511                 level= 2*get_bits1(&s->gb)-1;
00512             else{
00513                 if(get_bits1(&s->gb))
00514                     level = get_bits(&s->gb, code-1) + (1<<(code-1));
00515                 else
00516                     level = -get_bits(&s->gb, code-1) - (1<<(code-1));
00517             }
00518         }else{
00519             level = get_xbits(&s->gb, code);
00520         }
00521 
00522         if (code > 8){
00523             if(get_bits1(&s->gb)==0){ /* marker */
00524                 if(s->error_recognition>=2){
00525                     av_log(s->avctx, AV_LOG_ERROR, "dc marker bit missing\n");
00526                     return -1;
00527                 }
00528             }
00529         }
00530     }
00531 
00532     return ff_mpeg4_pred_dc(s, n, level, dir_ptr, 0);
00533 }
00534 
00539 static int mpeg4_decode_partition_a(MpegEncContext *s){
00540     int mb_num;
00541     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
00542 
00543     /* decode first partition */
00544     mb_num=0;
00545     s->first_slice_line=1;
00546     for(; s->mb_y<s->mb_height; s->mb_y++){
00547         ff_init_block_index(s);
00548         for(; s->mb_x<s->mb_width; s->mb_x++){
00549             const int xy= s->mb_x + s->mb_y*s->mb_stride;
00550             int cbpc;
00551             int dir=0;
00552 
00553             mb_num++;
00554             ff_update_block_index(s);
00555             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
00556                 s->first_slice_line=0;
00557 
00558             if(s->pict_type==FF_I_TYPE){
00559                 int i;
00560 
00561                 do{
00562                     if(show_bits_long(&s->gb, 19)==DC_MARKER){
00563                         return mb_num-1;
00564                     }
00565 
00566                     cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
00567                     if (cbpc < 0){
00568                         av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
00569                         return -1;
00570                     }
00571                 }while(cbpc == 8);
00572 
00573                 s->cbp_table[xy]= cbpc & 3;
00574                 s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
00575                 s->mb_intra = 1;
00576 
00577                 if(cbpc & 4) {
00578                     ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
00579                 }
00580                 s->current_picture.qscale_table[xy]= s->qscale;
00581 
00582                 s->mbintra_table[xy]= 1;
00583                 for(i=0; i<6; i++){
00584                     int dc_pred_dir;
00585                     int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
00586                     if(dc < 0){
00587                         av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
00588                         return -1;
00589                     }
00590                     dir<<=1;
00591                     if(dc_pred_dir) dir|=1;
00592                 }
00593                 s->pred_dir_table[xy]= dir;
00594             }else{ /* P/S_TYPE */
00595                 int mx, my, pred_x, pred_y, bits;
00596                 int16_t * const mot_val= s->current_picture.motion_val[0][s->block_index[0]];
00597                 const int stride= s->b8_stride*2;
00598 
00599 try_again:
00600                 bits= show_bits(&s->gb, 17);
00601                 if(bits==MOTION_MARKER){
00602                     return mb_num-1;
00603                 }
00604                 skip_bits1(&s->gb);
00605                 if(bits&0x10000){
00606                     /* skip mb */
00607                     if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
00608                         s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
00609                         mx= get_amv(s, 0);
00610                         my= get_amv(s, 1);
00611                     }else{
00612                         s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
00613                         mx=my=0;
00614                     }
00615                     mot_val[0       ]= mot_val[2       ]=
00616                     mot_val[0+stride]= mot_val[2+stride]= mx;
00617                     mot_val[1       ]= mot_val[3       ]=
00618                     mot_val[1+stride]= mot_val[3+stride]= my;
00619 
00620                     if(s->mbintra_table[xy])
00621                         ff_clean_intra_table_entries(s);
00622                     continue;
00623                 }
00624 
00625                 cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
00626                 if (cbpc < 0){
00627                     av_log(s->avctx, AV_LOG_ERROR, "cbpc corrupted at %d %d\n", s->mb_x, s->mb_y);
00628                     return -1;
00629                 }
00630                 if(cbpc == 20)
00631                     goto try_again;
00632 
00633                 s->cbp_table[xy]= cbpc&(8+3); //8 is dquant
00634 
00635                 s->mb_intra = ((cbpc & 4) != 0);
00636 
00637                 if(s->mb_intra){
00638                     s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
00639                     s->mbintra_table[xy]= 1;
00640                     mot_val[0       ]= mot_val[2       ]=
00641                     mot_val[0+stride]= mot_val[2+stride]= 0;
00642                     mot_val[1       ]= mot_val[3       ]=
00643                     mot_val[1+stride]= mot_val[3+stride]= 0;
00644                 }else{
00645                     if(s->mbintra_table[xy])
00646                         ff_clean_intra_table_entries(s);
00647 
00648                     if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
00649                         s->mcsel= get_bits1(&s->gb);
00650                     else s->mcsel= 0;
00651 
00652                     if ((cbpc & 16) == 0) {
00653                         /* 16x16 motion prediction */
00654 
00655                         h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
00656                         if(!s->mcsel){
00657                             mx = h263_decode_motion(s, pred_x, s->f_code);
00658                             if (mx >= 0xffff)
00659                                 return -1;
00660 
00661                             my = h263_decode_motion(s, pred_y, s->f_code);
00662                             if (my >= 0xffff)
00663                                 return -1;
00664                             s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
00665                         } else {
00666                             mx = get_amv(s, 0);
00667                             my = get_amv(s, 1);
00668                             s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_GMC | MB_TYPE_L0;
00669                         }
00670 
00671                         mot_val[0       ]= mot_val[2       ] =
00672                         mot_val[0+stride]= mot_val[2+stride]= mx;
00673                         mot_val[1       ]= mot_val[3       ]=
00674                         mot_val[1+stride]= mot_val[3+stride]= my;
00675                     } else {
00676                         int i;
00677                         s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0;
00678                         for(i=0;i<4;i++) {
00679                             int16_t *mot_val= h263_pred_motion(s, i, 0, &pred_x, &pred_y);
00680                             mx = h263_decode_motion(s, pred_x, s->f_code);
00681                             if (mx >= 0xffff)
00682                                 return -1;
00683 
00684                             my = h263_decode_motion(s, pred_y, s->f_code);
00685                             if (my >= 0xffff)
00686                                 return -1;
00687                             mot_val[0] = mx;
00688                             mot_val[1] = my;
00689                         }
00690                     }
00691                 }
00692             }
00693         }
00694         s->mb_x= 0;
00695     }
00696 
00697     return mb_num;
00698 }
00699 
00704 static int mpeg4_decode_partition_b(MpegEncContext *s, int mb_count){
00705     int mb_num=0;
00706     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
00707 
00708     s->mb_x= s->resync_mb_x;
00709     s->first_slice_line=1;
00710     for(s->mb_y= s->resync_mb_y; mb_num < mb_count; s->mb_y++){
00711         ff_init_block_index(s);
00712         for(; mb_num < mb_count && s->mb_x<s->mb_width; s->mb_x++){
00713             const int xy= s->mb_x + s->mb_y*s->mb_stride;
00714 
00715             mb_num++;
00716             ff_update_block_index(s);
00717             if(s->mb_x == s->resync_mb_x && s->mb_y == s->resync_mb_y+1)
00718                 s->first_slice_line=0;
00719 
00720             if(s->pict_type==FF_I_TYPE){
00721                 int ac_pred= get_bits1(&s->gb);
00722                 int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
00723                 if(cbpy<0){
00724                     av_log(s->avctx, AV_LOG_ERROR, "cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
00725                     return -1;
00726                 }
00727 
00728                 s->cbp_table[xy]|= cbpy<<2;
00729                 s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
00730             }else{ /* P || S_TYPE */
00731                 if(IS_INTRA(s->current_picture.mb_type[xy])){
00732                     int dir=0,i;
00733                     int ac_pred = get_bits1(&s->gb);
00734                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
00735 
00736                     if(cbpy<0){
00737                         av_log(s->avctx, AV_LOG_ERROR, "I cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
00738                         return -1;
00739                     }
00740 
00741                     if(s->cbp_table[xy] & 8) {
00742                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
00743                     }
00744                     s->current_picture.qscale_table[xy]= s->qscale;
00745 
00746                     for(i=0; i<6; i++){
00747                         int dc_pred_dir;
00748                         int dc= mpeg4_decode_dc(s, i, &dc_pred_dir);
00749                         if(dc < 0){
00750                             av_log(s->avctx, AV_LOG_ERROR, "DC corrupted at %d %d\n", s->mb_x, s->mb_y);
00751                             return -1;
00752                         }
00753                         dir<<=1;
00754                         if(dc_pred_dir) dir|=1;
00755                     }
00756                     s->cbp_table[xy]&= 3; //remove dquant
00757                     s->cbp_table[xy]|= cbpy<<2;
00758                     s->current_picture.mb_type[xy] |= ac_pred*MB_TYPE_ACPRED;
00759                     s->pred_dir_table[xy]= dir;
00760                 }else if(IS_SKIP(s->current_picture.mb_type[xy])){
00761                     s->current_picture.qscale_table[xy]= s->qscale;
00762                     s->cbp_table[xy]= 0;
00763                 }else{
00764                     int cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
00765 
00766                     if(cbpy<0){
00767                         av_log(s->avctx, AV_LOG_ERROR, "P cbpy corrupted at %d %d\n", s->mb_x, s->mb_y);
00768                         return -1;
00769                     }
00770 
00771                     if(s->cbp_table[xy] & 8) {
00772                         ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
00773                     }
00774                     s->current_picture.qscale_table[xy]= s->qscale;
00775 
00776                     s->cbp_table[xy]&= 3; //remove dquant
00777                     s->cbp_table[xy]|= (cbpy^0xf)<<2;
00778                 }
00779             }
00780         }
00781         if(mb_num >= mb_count) return 0;
00782         s->mb_x= 0;
00783     }
00784     return 0;
00785 }
00786 
00791 int ff_mpeg4_decode_partitions(MpegEncContext *s)
00792 {
00793     int mb_num;
00794     const int part_a_error= s->pict_type==FF_I_TYPE ? (DC_ERROR|MV_ERROR) : MV_ERROR;
00795     const int part_a_end  = s->pict_type==FF_I_TYPE ? (DC_END  |MV_END)   : MV_END;
00796 
00797     mb_num= mpeg4_decode_partition_a(s);
00798     if(mb_num<0){
00799         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
00800         return -1;
00801     }
00802 
00803     if(s->resync_mb_x + s->resync_mb_y*s->mb_width + mb_num > s->mb_num){
00804         av_log(s->avctx, AV_LOG_ERROR, "slice below monitor ...\n");
00805         ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, part_a_error);
00806         return -1;
00807     }
00808 
00809     s->mb_num_left= mb_num;
00810 
00811     if(s->pict_type==FF_I_TYPE){
00812         while(show_bits(&s->gb, 9) == 1)
00813             skip_bits(&s->gb, 9);
00814         if(get_bits_long(&s->gb, 19)!=DC_MARKER){
00815             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first I partition at %d %d\n", s->mb_x, s->mb_y);
00816             return -1;
00817         }
00818     }else{
00819         while(show_bits(&s->gb, 10) == 1)
00820             skip_bits(&s->gb, 10);
00821         if(get_bits(&s->gb, 17)!=MOTION_MARKER){
00822             av_log(s->avctx, AV_LOG_ERROR, "marker missing after first P partition at %d %d\n", s->mb_x, s->mb_y);
00823             return -1;
00824         }
00825     }
00826     ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, part_a_end);
00827 
00828     if( mpeg4_decode_partition_b(s, mb_num) < 0){
00829         if(s->pict_type==FF_P_TYPE)
00830             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, DC_ERROR);
00831         return -1;
00832     }else{
00833         if(s->pict_type==FF_P_TYPE)
00834             ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, DC_END);
00835     }
00836 
00837     return 0;
00838 }
00839 
00844 static inline int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
00845                               int n, int coded, int intra, int rvlc)
00846 {
00847     int level, i, last, run;
00848     int dc_pred_dir;
00849     RLTable * rl;
00850     RL_VLC_ELEM * rl_vlc;
00851     const uint8_t * scan_table;
00852     int qmul, qadd;
00853 
00854     //Note intra & rvlc should be optimized away if this is inlined
00855 
00856     if(intra) {
00857       if(s->use_intra_dc_vlc){
00858         /* DC coef */
00859         if(s->partitioned_frame){
00860             level = s->dc_val[0][ s->block_index[n] ];
00861             if(n<4) level= FASTDIV((level + (s->y_dc_scale>>1)), s->y_dc_scale);
00862             else    level= FASTDIV((level + (s->c_dc_scale>>1)), s->c_dc_scale);
00863             dc_pred_dir= (s->pred_dir_table[s->mb_x + s->mb_y*s->mb_stride]<<n)&32;
00864         }else{
00865             level = mpeg4_decode_dc(s, n, &dc_pred_dir);
00866             if (level < 0)
00867                 return -1;
00868         }
00869         block[0] = level;
00870         i = 0;
00871       }else{
00872             i = -1;
00873             ff_mpeg4_pred_dc(s, n, 0, &dc_pred_dir, 0);
00874       }
00875       if (!coded)
00876           goto not_coded;
00877 
00878       if(rvlc){
00879           rl = &rvlc_rl_intra;
00880           rl_vlc = rvlc_rl_intra.rl_vlc[0];
00881       }else{
00882           rl = &ff_mpeg4_rl_intra;
00883           rl_vlc = ff_mpeg4_rl_intra.rl_vlc[0];
00884       }
00885       if (s->ac_pred) {
00886           if (dc_pred_dir == 0)
00887               scan_table = s->intra_v_scantable.permutated; /* left */
00888           else
00889               scan_table = s->intra_h_scantable.permutated; /* top */
00890       } else {
00891             scan_table = s->intra_scantable.permutated;
00892       }
00893       qmul=1;
00894       qadd=0;
00895     } else {
00896         i = -1;
00897         if (!coded) {
00898             s->block_last_index[n] = i;
00899             return 0;
00900         }
00901         if(rvlc) rl = &rvlc_rl_inter;
00902         else     rl = &ff_h263_rl_inter;
00903 
00904         scan_table = s->intra_scantable.permutated;
00905 
00906         if(s->mpeg_quant){
00907             qmul=1;
00908             qadd=0;
00909             if(rvlc){
00910                 rl_vlc = rvlc_rl_inter.rl_vlc[0];
00911             }else{
00912                 rl_vlc = ff_h263_rl_inter.rl_vlc[0];
00913             }
00914         }else{
00915             qmul = s->qscale << 1;
00916             qadd = (s->qscale - 1) | 1;
00917             if(rvlc){
00918                 rl_vlc = rvlc_rl_inter.rl_vlc[s->qscale];
00919             }else{
00920                 rl_vlc = ff_h263_rl_inter.rl_vlc[s->qscale];
00921             }
00922         }
00923     }
00924   {
00925     OPEN_READER(re, &s->gb);
00926     for(;;) {
00927         UPDATE_CACHE(re, &s->gb);
00928         GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 0);
00929         if (level==0) {
00930           /* escape */
00931           if(rvlc){
00932                 if(SHOW_UBITS(re, &s->gb, 1)==0){
00933                     av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in rvlc esc\n");
00934                     return -1;
00935                 }; SKIP_CACHE(re, &s->gb, 1);
00936 
00937                 last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
00938                 run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
00939                 SKIP_COUNTER(re, &s->gb, 1+1+6);
00940                 UPDATE_CACHE(re, &s->gb);
00941 
00942                 if(SHOW_UBITS(re, &s->gb, 1)==0){
00943                     av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in rvlc esc\n");
00944                     return -1;
00945                 }; SKIP_CACHE(re, &s->gb, 1);
00946 
00947                 level= SHOW_UBITS(re, &s->gb, 11); SKIP_CACHE(re, &s->gb, 11);
00948 
00949                 if(SHOW_UBITS(re, &s->gb, 5)!=0x10){
00950                     av_log(s->avctx, AV_LOG_ERROR, "reverse esc missing\n");
00951                     return -1;
00952                 }; SKIP_CACHE(re, &s->gb, 5);
00953 
00954                 level=  level * qmul + qadd;
00955                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1); LAST_SKIP_CACHE(re, &s->gb, 1);
00956                 SKIP_COUNTER(re, &s->gb, 1+11+5+1);
00957 
00958                 i+= run + 1;
00959                 if(last) i+=192;
00960           }else{
00961             int cache;
00962             cache= GET_CACHE(re, &s->gb);
00963 
00964             if(IS_3IV1)
00965                 cache ^= 0xC0000000;
00966 
00967             if (cache&0x80000000) {
00968                 if (cache&0x40000000) {
00969                     /* third escape */
00970                     SKIP_CACHE(re, &s->gb, 2);
00971                     last=  SHOW_UBITS(re, &s->gb, 1); SKIP_CACHE(re, &s->gb, 1);
00972                     run=   SHOW_UBITS(re, &s->gb, 6); LAST_SKIP_CACHE(re, &s->gb, 6);
00973                     SKIP_COUNTER(re, &s->gb, 2+1+6);
00974                     UPDATE_CACHE(re, &s->gb);
00975 
00976                     if(IS_3IV1){
00977                         level= SHOW_SBITS(re, &s->gb, 12); LAST_SKIP_BITS(re, &s->gb, 12);
00978                     }else{
00979                         if(SHOW_UBITS(re, &s->gb, 1)==0){
00980                             av_log(s->avctx, AV_LOG_ERROR, "1. marker bit missing in 3. esc\n");
00981                             return -1;
00982                         }; SKIP_CACHE(re, &s->gb, 1);
00983 
00984                         level= SHOW_SBITS(re, &s->gb, 12); SKIP_CACHE(re, &s->gb, 12);
00985 
00986                         if(SHOW_UBITS(re, &s->gb, 1)==0){
00987                             av_log(s->avctx, AV_LOG_ERROR, "2. marker bit missing in 3. esc\n");
00988                             return -1;
00989                         }; LAST_SKIP_CACHE(re, &s->gb, 1);
00990 
00991                         SKIP_COUNTER(re, &s->gb, 1+12+1);
00992                     }
00993 
00994 #if 0
00995                     if(s->error_recognition >= FF_ER_COMPLIANT){
00996                         const int abs_level= FFABS(level);
00997                         if(abs_level<=MAX_LEVEL && run<=MAX_RUN){
00998                             const int run1= run - rl->max_run[last][abs_level] - 1;
00999                             if(abs_level <= rl->max_level[last][run]){
01000                                 av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, vlc encoding possible\n");
01001                                 return -1;
01002                             }
01003                             if(s->error_recognition > FF_ER_COMPLIANT){
01004                                 if(abs_level <= rl->max_level[last][run]*2){
01005                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 1 encoding possible\n");
01006                                     return -1;
01007                                 }
01008                                 if(run1 >= 0 && abs_level <= rl->max_level[last][run1]){
01009                                     av_log(s->avctx, AV_LOG_ERROR, "illegal 3. esc, esc 2 encoding possible\n");
01010                                     return -1;
01011                                 }
01012                             }
01013                         }
01014                     }
01015 #endif
01016                     if (level>0) level= level * qmul + qadd;
01017                     else         level= level * qmul - qadd;
01018 
01019                     if((unsigned)(level + 2048) > 4095){
01020                         if(s->error_recognition > FF_ER_COMPLIANT){
01021                             if(level > 2560 || level<-2560){
01022                                 av_log(s->avctx, AV_LOG_ERROR, "|level| overflow in 3. esc, qp=%d\n", s->qscale);
01023                                 return -1;
01024                             }
01025                         }
01026                         level= level<0 ? -2048 : 2047;
01027                     }
01028 
01029                     i+= run + 1;
01030                     if(last) i+=192;
01031                 } else {
01032                     /* second escape */
01033                     SKIP_BITS(re, &s->gb, 2);
01034                     GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
01035                     i+= run + rl->max_run[run>>7][level/qmul] +1; //FIXME opt indexing
01036                     level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
01037                     LAST_SKIP_BITS(re, &s->gb, 1);
01038                 }
01039             } else {
01040                 /* first escape */
01041                 SKIP_BITS(re, &s->gb, 1);
01042                 GET_RL_VLC(level, run, re, &s->gb, rl_vlc, TEX_VLC_BITS, 2, 1);
01043                 i+= run;
01044                 level = level + rl->max_level[run>>7][(run-1)&63] * qmul;//FIXME opt indexing
01045                 level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
01046                 LAST_SKIP_BITS(re, &s->gb, 1);
01047             }
01048           }
01049         } else {
01050             i+= run;
01051             level = (level ^ SHOW_SBITS(re, &s->gb, 1)) - SHOW_SBITS(re, &s->gb, 1);
01052             LAST_SKIP_BITS(re, &s->gb, 1);
01053         }
01054         if (i > 62){
01055             i-= 192;
01056             if(i&(~63)){
01057                 av_log(s->avctx, AV_LOG_ERROR, "ac-tex damaged at %d %d\n", s->mb_x, s->mb_y);
01058                 return -1;
01059             }
01060 
01061             block[scan_table[i]] = level;
01062             break;
01063         }
01064 
01065         block[scan_table[i]] = level;
01066     }
01067     CLOSE_READER(re, &s->gb);
01068   }
01069  not_coded:
01070     if (intra) {
01071         if(!s->use_intra_dc_vlc){
01072             block[0] = ff_mpeg4_pred_dc(s, n, block[0], &dc_pred_dir, 0);
01073 
01074             i -= i>>31; //if(i == -1) i=0;
01075         }
01076 
01077         mpeg4_pred_ac(s, block, n, dc_pred_dir);
01078         if (s->ac_pred) {
01079             i = 63; /* XXX: not optimal */
01080         }
01081     }
01082     s->block_last_index[n] = i;
01083     return 0;
01084 }
01085 
01090 static int mpeg4_decode_partitioned_mb(MpegEncContext *s, DCTELEM block[6][64])
01091 {
01092     int cbp, mb_type;
01093     const int xy= s->mb_x + s->mb_y*s->mb_stride;
01094 
01095     mb_type= s->current_picture.mb_type[xy];
01096     cbp = s->cbp_table[xy];
01097 
01098     s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
01099 
01100     if(s->current_picture.qscale_table[xy] != s->qscale){
01101         ff_set_qscale(s, s->current_picture.qscale_table[xy] );
01102     }
01103 
01104     if (s->pict_type == FF_P_TYPE || s->pict_type==FF_S_TYPE) {
01105         int i;
01106         for(i=0; i<4; i++){
01107             s->mv[0][i][0] = s->current_picture.motion_val[0][ s->block_index[i] ][0];
01108             s->mv[0][i][1] = s->current_picture.motion_val[0][ s->block_index[i] ][1];
01109         }
01110         s->mb_intra = IS_INTRA(mb_type);
01111 
01112         if (IS_SKIP(mb_type)) {
01113             /* skip mb */
01114             for(i=0;i<6;i++)
01115                 s->block_last_index[i] = -1;
01116             s->mv_dir = MV_DIR_FORWARD;
01117             s->mv_type = MV_TYPE_16X16;
01118             if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
01119                 s->mcsel=1;
01120                 s->mb_skipped = 0;
01121             }else{
01122                 s->mcsel=0;
01123                 s->mb_skipped = 1;
01124             }
01125         }else if(s->mb_intra){
01126             s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
01127         }else if(!s->mb_intra){
01128 //            s->mcsel= 0; //FIXME do we need to init that
01129 
01130             s->mv_dir = MV_DIR_FORWARD;
01131             if (IS_8X8(mb_type)) {
01132                 s->mv_type = MV_TYPE_8X8;
01133             } else {
01134                 s->mv_type = MV_TYPE_16X16;
01135             }
01136         }
01137     } else { /* I-Frame */
01138         s->mb_intra = 1;
01139         s->ac_pred = IS_ACPRED(s->current_picture.mb_type[xy]);
01140     }
01141 
01142     if (!IS_SKIP(mb_type)) {
01143         int i;
01144         s->dsp.clear_blocks(s->block[0]);
01145         /* decode each block */
01146         for (i = 0; i < 6; i++) {
01147             if(mpeg4_decode_block(s, block[i], i, cbp&32, s->mb_intra, s->rvlc) < 0){
01148                 av_log(s->avctx, AV_LOG_ERROR, "texture corrupted at %d %d %d\n", s->mb_x, s->mb_y, s->mb_intra);
01149                 return -1;
01150             }
01151             cbp+=cbp;
01152         }
01153     }
01154 
01155     /* per-MB end of slice check */
01156 
01157     if(--s->mb_num_left <= 0){
01158         if(mpeg4_is_resync(s))
01159             return SLICE_END;
01160         else
01161             return SLICE_NOEND;
01162     }else{
01163         if(mpeg4_is_resync(s)){
01164             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
01165             if(s->cbp_table[xy+delta])
01166                 return SLICE_END;
01167         }
01168         return SLICE_OK;
01169     }
01170 }
01171 
01172 static int mpeg4_decode_mb(MpegEncContext *s,
01173                       DCTELEM block[6][64])
01174 {
01175     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
01176     int16_t *mot_val;
01177     static int8_t quant_tab[4] = { -1, -2, 1, 2 };
01178     const int xy= s->mb_x + s->mb_y * s->mb_stride;
01179 
01180     assert(s->h263_pred);
01181 
01182     if (s->pict_type == FF_P_TYPE || s->pict_type==FF_S_TYPE) {
01183         do{
01184             if (get_bits1(&s->gb)) {
01185                 /* skip mb */
01186                 s->mb_intra = 0;
01187                 for(i=0;i<6;i++)
01188                     s->block_last_index[i] = -1;
01189                 s->mv_dir = MV_DIR_FORWARD;
01190                 s->mv_type = MV_TYPE_16X16;
01191                 if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE){
01192                     s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
01193                     s->mcsel=1;
01194                     s->mv[0][0][0]= get_amv(s, 0);
01195                     s->mv[0][0][1]= get_amv(s, 1);
01196 
01197                     s->mb_skipped = 0;
01198                 }else{
01199                     s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
01200                     s->mcsel=0;
01201                     s->mv[0][0][0] = 0;
01202                     s->mv[0][0][1] = 0;
01203                     s->mb_skipped = 1;
01204                 }
01205                 goto end;
01206             }
01207             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
01208             if (cbpc < 0){
01209                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
01210                 return -1;
01211             }
01212         }while(cbpc == 20);
01213 
01214         s->dsp.clear_blocks(s->block[0]);
01215         dquant = cbpc & 8;
01216         s->mb_intra = ((cbpc & 4) != 0);
01217         if (s->mb_intra) goto intra;
01218 
01219         if(s->pict_type==FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE && (cbpc & 16) == 0)
01220             s->mcsel= get_bits1(&s->gb);
01221         else s->mcsel= 0;
01222         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1) ^ 0x0F;
01223 
01224         cbp = (cbpc & 3) | (cbpy << 2);
01225         if (dquant) {
01226             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
01227         }
01228         if((!s->progressive_sequence) && (cbp || (s->workaround_bugs&FF_BUG_XVID_ILACE)))
01229             s->interlaced_dct= get_bits1(&s->gb);
01230 
01231         s->mv_dir = MV_DIR_FORWARD;
01232         if ((cbpc & 16) == 0) {
01233             if(s->mcsel){
01234                 s->current_picture.mb_type[xy]= MB_TYPE_GMC | MB_TYPE_16x16 | MB_TYPE_L0;
01235                 /* 16x16 global motion prediction */
01236                 s->mv_type = MV_TYPE_16X16;
01237                 mx= get_amv(s, 0);
01238                 my= get_amv(s, 1);
01239                 s->mv[0][0][0] = mx;
01240                 s->mv[0][0][1] = my;
01241             }else if((!s->progressive_sequence) && get_bits1(&s->gb)){
01242                 s->current_picture.mb_type[xy]= MB_TYPE_16x8 | MB_TYPE_L0 | MB_TYPE_INTERLACED;
01243                 /* 16x8 field motion prediction */
01244                 s->mv_type= MV_TYPE_FIELD;
01245 
01246                 s->field_select[0][0]= get_bits1(&s->gb);
01247                 s->field_select[0][1]= get_bits1(&s->gb);
01248 
01249                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
01250 
01251                 for(i=0; i<2; i++){
01252                     mx = h263_decode_motion(s, pred_x, s->f_code);
01253                     if (mx >= 0xffff)
01254                         return -1;
01255 
01256                     my = h263_decode_motion(s, pred_y/2, s->f_code);
01257                     if (my >= 0xffff)
01258                         return -1;
01259 
01260                     s->mv[0][i][0] = mx;
01261                     s->mv[0][i][1] = my;
01262                 }
01263             }else{
01264                 s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0;
01265                 /* 16x16 motion prediction */
01266                 s->mv_type = MV_TYPE_16X16;
01267                 h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
01268                 mx = h263_decode_motion(s, pred_x, s->f_code);
01269 
01270                 if (mx >= 0xffff)
01271                     return -1;
01272 
01273                 my = h263_decode_motion(s, pred_y, s->f_code);
01274 
01275                 if (my >= 0xffff)
01276                     return -1;
01277                 s->mv[0][0][0] = mx;
01278                 s->mv[0][0][1] = my;
01279             }
01280         } else {
01281             s->current_picture.mb_type[xy]= MB_TYPE_8x8 | MB_TYPE_L0;
01282             s->mv_type = MV_TYPE_8X8;
01283             for(i=0;i<4;i++) {
01284                 mot_val = h263_pred_motion(s, i, 0, &pred_x, &pred_y);
01285                 mx = h263_decode_motion(s, pred_x, s->f_code);
01286                 if (mx >= 0xffff)
01287                     return -1;
01288 
01289                 my = h263_decode_motion(s, pred_y, s->f_code);
01290                 if (my >= 0xffff)
01291                     return -1;
01292                 s->mv[0][i][0] = mx;
01293                 s->mv[0][i][1] = my;
01294                 mot_val[0] = mx;
01295                 mot_val[1] = my;
01296             }
01297         }
01298     } else if(s->pict_type==FF_B_TYPE) {
01299         int modb1; // first bit of modb
01300         int modb2; // second bit of modb
01301         int mb_type;
01302 
01303         s->mb_intra = 0; //B-frames never contain intra blocks
01304         s->mcsel=0;      //     ...               true gmc blocks
01305 
01306         if(s->mb_x==0){
01307             for(i=0; i<2; i++){
01308                 s->last_mv[i][0][0]=
01309                 s->last_mv[i][0][1]=
01310                 s->last_mv[i][1][0]=
01311                 s->last_mv[i][1][1]= 0;
01312             }
01313 
01314             ff_thread_await_progress((AVFrame*)s->next_picture_ptr, s->mb_y, 0);
01315         }
01316 
01317         /* if we skipped it in the future P Frame than skip it now too */
01318         s->mb_skipped= s->next_picture.mbskip_table[s->mb_y * s->mb_stride + s->mb_x]; // Note, skiptab=0 if last was GMC
01319 
01320         if(s->mb_skipped){
01321                 /* skip mb */
01322             for(i=0;i<6;i++)
01323                 s->block_last_index[i] = -1;
01324 
01325             s->mv_dir = MV_DIR_FORWARD;
01326             s->mv_type = MV_TYPE_16X16;
01327             s->mv[0][0][0] = 0;
01328             s->mv[0][0][1] = 0;
01329             s->mv[1][0][0] = 0;
01330             s->mv[1][0][1] = 0;
01331             s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
01332             goto end;
01333         }
01334 
01335         modb1= get_bits1(&s->gb);
01336         if(modb1){
01337             mb_type= MB_TYPE_DIRECT2 | MB_TYPE_SKIP | MB_TYPE_L0L1; //like MB_TYPE_B_DIRECT but no vectors coded
01338             cbp=0;
01339         }else{
01340             modb2= get_bits1(&s->gb);
01341             mb_type= get_vlc2(&s->gb, mb_type_b_vlc.table, MB_TYPE_B_VLC_BITS, 1);
01342             if(mb_type<0){
01343                 av_log(s->avctx, AV_LOG_ERROR, "illegal MB_type\n");
01344                 return -1;
01345             }
01346             mb_type= mb_type_b_map[ mb_type ];
01347             if(modb2) cbp= 0;
01348             else{
01349                 s->dsp.clear_blocks(s->block[0]);
01350                 cbp= get_bits(&s->gb, 6);
01351             }
01352 
01353             if ((!IS_DIRECT(mb_type)) && cbp) {
01354                 if(get_bits1(&s->gb)){
01355                     ff_set_qscale(s, s->qscale + get_bits1(&s->gb)*4 - 2);
01356                 }
01357             }
01358 
01359             if(!s->progressive_sequence){
01360                 if(cbp)
01361                     s->interlaced_dct= get_bits1(&s->gb);
01362 
01363                 if(!IS_DIRECT(mb_type) && get_bits1(&s->gb)){
01364                     mb_type |= MB_TYPE_16x8 | MB_TYPE_INTERLACED;
01365                     mb_type &= ~MB_TYPE_16x16;
01366 
01367                     if(USES_LIST(mb_type, 0)){
01368                         s->field_select[0][0]= get_bits1(&s->gb);
01369                         s->field_select[0][1]= get_bits1(&s->gb);
01370                     }
01371                     if(USES_LIST(mb_type, 1)){
01372                         s->field_select[1][0]= get_bits1(&s->gb);
01373                         s->field_select[1][1]= get_bits1(&s->gb);
01374                     }
01375                 }
01376             }
01377 
01378             s->mv_dir = 0;
01379             if((mb_type & (MB_TYPE_DIRECT2|MB_TYPE_INTERLACED)) == 0){
01380                 s->mv_type= MV_TYPE_16X16;
01381 
01382                 if(USES_LIST(mb_type, 0)){
01383                     s->mv_dir = MV_DIR_FORWARD;
01384 
01385                     mx = h263_decode_motion(s, s->last_mv[0][0][0], s->f_code);
01386                     my = h263_decode_motion(s, s->last_mv[0][0][1], s->f_code);
01387                     s->last_mv[0][1][0]= s->last_mv[0][0][0]= s->mv[0][0][0] = mx;
01388                     s->last_mv[0][1][1]= s->last_mv[0][0][1]= s->mv[0][0][1] = my;
01389                 }
01390 
01391                 if(USES_LIST(mb_type, 1)){
01392                     s->mv_dir |= MV_DIR_BACKWARD;
01393 
01394                     mx = h263_decode_motion(s, s->last_mv[1][0][0], s->b_code);
01395                     my = h263_decode_motion(s, s->last_mv[1][0][1], s->b_code);
01396                     s->last_mv[1][1][0]= s->last_mv[1][0][0]= s->mv[1][0][0] = mx;
01397                     s->last_mv[1][1][1]= s->last_mv[1][0][1]= s->mv[1][0][1] = my;
01398                 }
01399             }else if(!IS_DIRECT(mb_type)){
01400                 s->mv_type= MV_TYPE_FIELD;
01401 
01402                 if(USES_LIST(mb_type, 0)){
01403                     s->mv_dir = MV_DIR_FORWARD;
01404 
01405                     for(i=0; i<2; i++){
01406                         mx = h263_decode_motion(s, s->last_mv[0][i][0]  , s->f_code);
01407                         my = h263_decode_motion(s, s->last_mv[0][i][1]/2, s->f_code);
01408                         s->last_mv[0][i][0]=  s->mv[0][i][0] = mx;
01409                         s->last_mv[0][i][1]= (s->mv[0][i][1] = my)*2;
01410                     }
01411                 }
01412 
01413                 if(USES_LIST(mb_type, 1)){
01414                     s->mv_dir |= MV_DIR_BACKWARD;
01415 
01416                     for(i=0; i<2; i++){
01417                         mx = h263_decode_motion(s, s->last_mv[1][i][0]  , s->b_code);
01418                         my = h263_decode_motion(s, s->last_mv[1][i][1]/2, s->b_code);
01419                         s->last_mv[1][i][0]=  s->mv[1][i][0] = mx;
01420                         s->last_mv[1][i][1]= (s->mv[1][i][1] = my)*2;
01421                     }
01422                 }
01423             }
01424         }
01425 
01426         if(IS_DIRECT(mb_type)){
01427             if(IS_SKIP(mb_type))
01428                 mx=my=0;
01429             else{
01430                 mx = h263_decode_motion(s, 0, 1);
01431                 my = h263_decode_motion(s, 0, 1);
01432             }
01433 
01434             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
01435             mb_type |= ff_mpeg4_set_direct_mv(s, mx, my);
01436         }
01437         s->current_picture.mb_type[xy]= mb_type;
01438     } else { /* I-Frame */
01439         do{
01440             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
01441             if (cbpc < 0){
01442                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
01443                 return -1;
01444             }
01445         }while(cbpc == 8);
01446 
01447         dquant = cbpc & 4;
01448         s->mb_intra = 1;
01449 intra:
01450         s->ac_pred = get_bits1(&s->gb);
01451         if(s->ac_pred)
01452             s->current_picture.mb_type[xy]= MB_TYPE_INTRA | MB_TYPE_ACPRED;
01453         else
01454             s->current_picture.mb_type[xy]= MB_TYPE_INTRA;
01455 
01456         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
01457         if(cbpy<0){
01458             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
01459             return -1;
01460         }
01461         cbp = (cbpc & 3) | (cbpy << 2);
01462 
01463         s->use_intra_dc_vlc= s->qscale < s->intra_dc_threshold;
01464 
01465         if (dquant) {
01466             ff_set_qscale(s, s->qscale + quant_tab[get_bits(&s->gb, 2)]);
01467         }
01468 
01469         if(!s->progressive_sequence)
01470             s->interlaced_dct= get_bits1(&s->gb);
01471 
01472         s->dsp.clear_blocks(s->block[0]);
01473         /* decode each block */
01474         for (i = 0; i < 6; i++) {
01475             if (mpeg4_decode_block(s, block[i], i, cbp&32, 1, 0) < 0)
01476                 return -1;
01477             cbp+=cbp;
01478         }
01479         goto end;
01480     }
01481 
01482     /* decode each block */
01483     for (i = 0; i < 6; i++) {
01484         if (mpeg4_decode_block(s, block[i], i, cbp&32, 0, 0) < 0)
01485             return -1;
01486         cbp+=cbp;
01487     }
01488 end:
01489 
01490         /* per-MB end of slice check */
01491     if(s->codec_id==CODEC_ID_MPEG4){
01492         if(mpeg4_is_resync(s)){
01493             const int delta= s->mb_x + 1 == s->mb_width ? 2 : 1;
01494 
01495             if(s->pict_type==FF_B_TYPE){
01496                 ff_thread_await_progress((AVFrame*)s->next_picture_ptr,
01497                                         (s->mb_x + delta >= s->mb_width) ? FFMIN(s->mb_y+1, s->mb_height-1) : s->mb_y, 0);
01498             }
01499 
01500             if(s->pict_type==FF_B_TYPE && s->next_picture.mbskip_table[xy + delta])
01501                 return SLICE_OK;
01502             return SLICE_END;
01503         }
01504     }
01505 
01506     return SLICE_OK;
01507 }
01508 
01509 
01510 static int mpeg4_decode_gop_header(MpegEncContext * s, GetBitContext *gb){
01511     int hours, minutes, seconds;
01512 
01513     if(!show_bits(gb, 23)){
01514         av_log(s->avctx, AV_LOG_WARNING, "GOP header invalid\n");
01515         return -1;
01516     }
01517 
01518     hours= get_bits(gb, 5);
01519     minutes= get_bits(gb, 6);
01520     skip_bits1(gb);
01521     seconds= get_bits(gb, 6);
01522 
01523     s->time_base= seconds + 60*(minutes + 60*hours);
01524 
01525     skip_bits1(gb);
01526     skip_bits1(gb);
01527 
01528     return 0;
01529 }
01530 
01531 static int decode_vol_header(MpegEncContext *s, GetBitContext *gb){
01532     int width, height, vo_ver_id;
01533 
01534     /* vol header */
01535     skip_bits(gb, 1); /* random access */
01536     s->vo_type= get_bits(gb, 8);
01537     if (get_bits1(gb) != 0) { /* is_ol_id */
01538         vo_ver_id = get_bits(gb, 4); /* vo_ver_id */
01539         skip_bits(gb, 3); /* vo_priority */
01540     } else {
01541         vo_ver_id = 1;
01542     }
01543     s->aspect_ratio_info= get_bits(gb, 4);
01544     if(s->aspect_ratio_info == FF_ASPECT_EXTENDED){
01545         s->avctx->sample_aspect_ratio.num= get_bits(gb, 8); // par_width
01546         s->avctx->sample_aspect_ratio.den= get_bits(gb, 8); // par_height
01547     }else{
01548         s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
01549     }
01550 
01551     if ((s->vol_control_parameters=get_bits1(gb))) { /* vol control parameter */
01552         int chroma_format= get_bits(gb, 2);
01553         if(chroma_format!=CHROMA_420){
01554             av_log(s->avctx, AV_LOG_ERROR, "illegal chroma format\n");
01555         }
01556         s->low_delay= get_bits1(gb);
01557         if(get_bits1(gb)){ /* vbv parameters */
01558             get_bits(gb, 15);   /* first_half_bitrate */
01559             skip_bits1(gb);     /* marker */
01560             get_bits(gb, 15);   /* latter_half_bitrate */
01561             skip_bits1(gb);     /* marker */
01562             get_bits(gb, 15);   /* first_half_vbv_buffer_size */
01563             skip_bits1(gb);     /* marker */
01564             get_bits(gb, 3);    /* latter_half_vbv_buffer_size */
01565             get_bits(gb, 11);   /* first_half_vbv_occupancy */
01566             skip_bits1(gb);     /* marker */
01567             get_bits(gb, 15);   /* latter_half_vbv_occupancy */
01568             skip_bits1(gb);     /* marker */
01569         }
01570     }else{
01571         // set low delay flag only once the smartest? low delay detection won't be overriden
01572         if(s->picture_number==0)
01573             s->low_delay=0;
01574     }
01575 
01576     s->shape = get_bits(gb, 2); /* vol shape */
01577     if(s->shape != RECT_SHAPE) av_log(s->avctx, AV_LOG_ERROR, "only rectangular vol supported\n");
01578     if(s->shape == GRAY_SHAPE && vo_ver_id != 1){
01579         av_log(s->avctx, AV_LOG_ERROR, "Gray shape not supported\n");
01580         skip_bits(gb, 4);  //video_object_layer_shape_extension
01581     }
01582 
01583     check_marker(gb, "before time_increment_resolution");
01584 
01585     s->avctx->time_base.den = get_bits(gb, 16);
01586     if(!s->avctx->time_base.den){
01587         av_log(s->avctx, AV_LOG_ERROR, "time_base.den==0\n");
01588         s->avctx->time_base.num = 0;
01589         return -1;
01590     }
01591 
01592     s->time_increment_bits = av_log2(s->avctx->time_base.den - 1) + 1;
01593     if (s->time_increment_bits < 1)
01594         s->time_increment_bits = 1;
01595 
01596     check_marker(gb, "before fixed_vop_rate");
01597 
01598     if (get_bits1(gb) != 0) {   /* fixed_vop_rate  */
01599         s->avctx->time_base.num = get_bits(gb, s->time_increment_bits);
01600     }else
01601         s->avctx->time_base.num = 1;
01602 
01603     s->t_frame=0;
01604 
01605     if (s->shape != BIN_ONLY_SHAPE) {
01606         if (s->shape == RECT_SHAPE) {
01607             skip_bits1(gb);   /* marker */
01608             width = get_bits(gb, 13);
01609             skip_bits1(gb);   /* marker */
01610             height = get_bits(gb, 13);
01611             skip_bits1(gb);   /* marker */
01612             if(width && height && !(s->width && s->codec_tag == AV_RL32("MP4S"))){ /* they should be non zero but who knows ... */
01613                 s->width = width;
01614                 s->height = height;
01615             }
01616         }
01617 
01618         s->progressive_sequence=
01619         s->progressive_frame= get_bits1(gb)^1;
01620         s->interlaced_dct=0;
01621         if(!get_bits1(gb) && (s->avctx->debug & FF_DEBUG_PICT_INFO))
01622             av_log(s->avctx, AV_LOG_INFO, "MPEG4 OBMC not supported (very likely buggy encoder)\n");   /* OBMC Disable */
01623         if (vo_ver_id == 1) {
01624             s->vol_sprite_usage = get_bits1(gb); /* vol_sprite_usage */
01625         } else {
01626             s->vol_sprite_usage = get_bits(gb, 2); /* vol_sprite_usage */
01627         }
01628         if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "Static Sprites not supported\n");
01629         if(s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE){
01630             if(s->vol_sprite_usage==STATIC_SPRITE){
01631                 s->sprite_width = get_bits(gb, 13);
01632                 skip_bits1(gb); /* marker */
01633                 s->sprite_height= get_bits(gb, 13);
01634                 skip_bits1(gb); /* marker */
01635                 s->sprite_left  = get_bits(gb, 13);
01636                 skip_bits1(gb); /* marker */
01637                 s->sprite_top   = get_bits(gb, 13);
01638                 skip_bits1(gb); /* marker */
01639             }
01640             s->num_sprite_warping_points= get_bits(gb, 6);
01641             if(s->num_sprite_warping_points > 3){
01642                 av_log(s->avctx, AV_LOG_ERROR, "%d sprite_warping_points\n", s->num_sprite_warping_points);
01643                 s->num_sprite_warping_points= 0;
01644                 return -1;
01645             }
01646             s->sprite_warping_accuracy = get_bits(gb, 2);
01647             s->sprite_brightness_change= get_bits1(gb);
01648             if(s->vol_sprite_usage==STATIC_SPRITE)
01649                 s->low_latency_sprite= get_bits1(gb);
01650         }
01651         // FIXME sadct disable bit if verid!=1 && shape not rect
01652 
01653         if (get_bits1(gb) == 1) {   /* not_8_bit */
01654             s->quant_precision = get_bits(gb, 4); /* quant_precision */
01655             if(get_bits(gb, 4)!=8) av_log(s->avctx, AV_LOG_ERROR, "N-bit not supported\n"); /* bits_per_pixel */
01656             if(s->quant_precision!=5) av_log(s->avctx, AV_LOG_ERROR, "quant precision %d\n", s->quant_precision);
01657         } else {
01658             s->quant_precision = 5;
01659         }
01660 
01661         // FIXME a bunch of grayscale shape things
01662 
01663         if((s->mpeg_quant=get_bits1(gb))){ /* vol_quant_type */
01664             int i, v;
01665 
01666             /* load default matrixes */
01667             for(i=0; i<64; i++){
01668                 int j= s->dsp.idct_permutation[i];
01669                 v= ff_mpeg4_default_intra_matrix[i];
01670                 s->intra_matrix[j]= v;
01671                 s->chroma_intra_matrix[j]= v;
01672 
01673                 v= ff_mpeg4_default_non_intra_matrix[i];
01674                 s->inter_matrix[j]= v;
01675                 s->chroma_inter_matrix[j]= v;
01676             }
01677 
01678             /* load custom intra matrix */
01679             if(get_bits1(gb)){
01680                 int last=0;
01681                 for(i=0; i<64; i++){
01682                     int j;
01683                     v= get_bits(gb, 8);
01684                     if(v==0) break;
01685 
01686                     last= v;
01687                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01688                     s->intra_matrix[j]= v;
01689                     s->chroma_intra_matrix[j]= v;
01690                 }
01691 
01692                 /* replicate last value */
01693                 for(; i<64; i++){
01694                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01695                     s->intra_matrix[j]= last;
01696                     s->chroma_intra_matrix[j]= last;
01697                 }
01698             }
01699 
01700             /* load custom non intra matrix */
01701             if(get_bits1(gb)){
01702                 int last=0;
01703                 for(i=0; i<64; i++){
01704                     int j;
01705                     v= get_bits(gb, 8);
01706                     if(v==0) break;
01707 
01708                     last= v;
01709                     j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01710                     s->inter_matrix[j]= v;
01711                     s->chroma_inter_matrix[j]= v;
01712                 }
01713 
01714                 /* replicate last value */
01715                 for(; i<64; i++){
01716                     int j= s->dsp.idct_permutation[ ff_zigzag_direct[i] ];
01717                     s->inter_matrix[j]= last;
01718                     s->chroma_inter_matrix[j]= last;
01719                 }
01720             }
01721 
01722             // FIXME a bunch of grayscale shape things
01723         }
01724 
01725         if(vo_ver_id != 1)
01726              s->quarter_sample= get_bits1(gb);
01727         else s->quarter_sample=0;
01728 
01729         if(!get_bits1(gb)){
01730             int pos= get_bits_count(gb);
01731             int estimation_method= get_bits(gb, 2);
01732             if(estimation_method<2){
01733                 if(!get_bits1(gb)){
01734                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //opaque
01735                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //transparent
01736                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_cae
01737                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //inter_cae
01738                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //no_update
01739                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //upampling
01740                 }
01741                 if(!get_bits1(gb)){
01742                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //intra_blocks
01743                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter_blocks
01744                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //inter4v_blocks
01745                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //not coded blocks
01746                 }
01747                 if(!check_marker(gb, "in complexity estimation part 1")){
01748                     skip_bits_long(gb, pos - get_bits_count(gb));
01749                     goto no_cplx_est;
01750                 }
01751                 if(!get_bits1(gb)){
01752                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_coeffs
01753                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //dct_lines
01754                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //vlc_syms
01755                     s->cplx_estimation_trash_i += 4*get_bits1(gb); //vlc_bits
01756                 }
01757                 if(!get_bits1(gb)){
01758                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //apm
01759                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //npm
01760                     s->cplx_estimation_trash_b += 8*get_bits1(gb); //interpolate_mc_q
01761                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //forwback_mc_q
01762                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel2
01763                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //halfpel4
01764                 }
01765                 if(!check_marker(gb, "in complexity estimation part 2")){
01766                     skip_bits_long(gb, pos - get_bits_count(gb));
01767                     goto no_cplx_est;
01768                 }
01769                 if(estimation_method==1){
01770                     s->cplx_estimation_trash_i += 8*get_bits1(gb); //sadct
01771                     s->cplx_estimation_trash_p += 8*get_bits1(gb); //qpel
01772                 }
01773             }else
01774                 av_log(s->avctx, AV_LOG_ERROR, "Invalid Complexity estimation method %d\n", estimation_method);
01775         }else{
01776 no_cplx_est:
01777             s->cplx_estimation_trash_i=
01778             s->cplx_estimation_trash_p=
01779             s->cplx_estimation_trash_b= 0;
01780         }
01781 
01782         s->resync_marker= !get_bits1(gb); /* resync_marker_disabled */
01783 
01784         s->data_partitioning= get_bits1(gb);
01785         if(s->data_partitioning){
01786             s->rvlc= get_bits1(gb);
01787         }
01788 
01789         if(vo_ver_id != 1) {
01790             s->new_pred= get_bits1(gb);
01791             if(s->new_pred){
01792                 av_log(s->avctx, AV_LOG_ERROR, "new pred not supported\n");
01793                 skip_bits(gb, 2); /* requested upstream message type */
01794                 skip_bits1(gb); /* newpred segment type */
01795             }
01796             s->reduced_res_vop= get_bits1(gb);
01797             if(s->reduced_res_vop) av_log(s->avctx, AV_LOG_ERROR, "reduced resolution VOP not supported\n");
01798         }
01799         else{
01800             s->new_pred=0;
01801             s->reduced_res_vop= 0;
01802         }
01803 
01804         s->scalability= get_bits1(gb);
01805 
01806         if (s->scalability) {
01807             GetBitContext bak= *gb;
01808             int ref_layer_id;
01809             int ref_layer_sampling_dir;
01810             int h_sampling_factor_n;
01811             int h_sampling_factor_m;
01812             int v_sampling_factor_n;
01813             int v_sampling_factor_m;
01814 
01815             s->hierachy_type= get_bits1(gb);
01816             ref_layer_id= get_bits(gb, 4);
01817             ref_layer_sampling_dir= get_bits1(gb);
01818             h_sampling_factor_n= get_bits(gb, 5);
01819             h_sampling_factor_m= get_bits(gb, 5);
01820             v_sampling_factor_n= get_bits(gb, 5);
01821             v_sampling_factor_m= get_bits(gb, 5);
01822             s->enhancement_type= get_bits1(gb);
01823 
01824             if(   h_sampling_factor_n==0 || h_sampling_factor_m==0
01825                || v_sampling_factor_n==0 || v_sampling_factor_m==0){
01826                 /* illegal scalability header (VERY broken encoder),
01827                  * trying to workaround */
01828                 s->scalability=0;
01829                 *gb= bak;
01830             }else
01831                 av_log(s->avctx, AV_LOG_ERROR, "scalability not supported\n");
01832 
01833             // bin shape stuff FIXME
01834         }
01835     }
01836     return 0;
01837 }
01838 
01843 static int decode_user_data(MpegEncContext *s, GetBitContext *gb){
01844     char buf[256];
01845     int i;
01846     int e;
01847     int ver = 0, build = 0, ver2 = 0, ver3 = 0;
01848     char last;
01849 
01850     for(i=0; i<255 && get_bits_count(gb) < gb->size_in_bits; i++){
01851         if(show_bits(gb, 23) == 0) break;
01852         buf[i]= get_bits(gb, 8);
01853     }
01854     buf[i]=0;
01855 
01856     /* divx detection */
01857     e=sscanf(buf, "DivX%dBuild%d%c", &ver, &build, &last);
01858     if(e<2)
01859         e=sscanf(buf, "DivX%db%d%c", &ver, &build, &last);
01860     if(e>=2){
01861         s->divx_version= ver;
01862         s->divx_build= build;
01863         s->divx_packed= e==3 && last=='p';
01864         if(s->divx_packed && !s->showed_packed_warning) {
01865             av_log(s->avctx, AV_LOG_WARNING, "Invalid and inefficient vfw-avi packed B frames detected\n");
01866             s->showed_packed_warning=1;
01867         }
01868     }
01869 
01870     /* ffmpeg detection */
01871     e=sscanf(buf, "FFmpe%*[^b]b%d", &build)+3;
01872     if(e!=4)
01873         e=sscanf(buf, "FFmpeg v%d.%d.%d / libavcodec build: %d", &ver, &ver2, &ver3, &build);
01874     if(e!=4){
01875         e=sscanf(buf, "Lavc%d.%d.%d", &ver, &ver2, &ver3)+1;
01876         if (e>1)
01877             build= (ver<<16) + (ver2<<8) + ver3;
01878     }
01879     if(e!=4){
01880         if(strcmp(buf, "ffmpeg")==0){
01881             s->lavc_build= 4600;
01882         }
01883     }
01884     if(e==4){
01885         s->lavc_build= build;
01886     }
01887 
01888     /* Xvid detection */
01889     e=sscanf(buf, "XviD%d", &build);
01890     if(e==1){
01891         s->xvid_build= build;
01892     }
01893 
01894     return 0;
01895 }
01896 
01897 static int decode_vop_header(MpegEncContext *s, GetBitContext *gb){
01898     int time_incr, time_increment;
01899 
01900     s->pict_type = get_bits(gb, 2) + FF_I_TYPE;        /* pict type: I = 0 , P = 1 */
01901     if(s->pict_type==FF_B_TYPE && s->low_delay && s->vol_control_parameters==0 && !(s->flags & CODEC_FLAG_LOW_DELAY)){
01902         av_log(s->avctx, AV_LOG_ERROR, "low_delay flag incorrectly, clearing it\n");
01903         s->low_delay=0;
01904     }
01905 
01906     s->partitioned_frame= s->data_partitioning && s->pict_type!=FF_B_TYPE;
01907     if(s->partitioned_frame)
01908         s->decode_mb= mpeg4_decode_partitioned_mb;
01909     else
01910         s->decode_mb= mpeg4_decode_mb;
01911 
01912     time_incr=0;
01913     while (get_bits1(gb) != 0)
01914         time_incr++;
01915 
01916     check_marker(gb, "before time_increment");
01917 
01918     if(s->time_increment_bits==0 || !(show_bits(gb, s->time_increment_bits+1)&1)){
01919         av_log(s->avctx, AV_LOG_ERROR, "hmm, seems the headers are not complete, trying to guess time_increment_bits\n");
01920 
01921         for(s->time_increment_bits=1 ;s->time_increment_bits<16; s->time_increment_bits++){
01922             if (    s->pict_type == FF_P_TYPE
01923                 || (s->pict_type == FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE)) {
01924                 if((show_bits(gb, s->time_increment_bits+6)&0x37) == 0x30) break;
01925             }else
01926                 if((show_bits(gb, s->time_increment_bits+5)&0x1F) == 0x18) break;
01927         }
01928 
01929         av_log(s->avctx, AV_LOG_ERROR, "my guess is %d bits ;)\n",s->time_increment_bits);
01930     }
01931 
01932     if(IS_3IV1) time_increment= get_bits1(gb); //FIXME investigate further
01933     else time_increment= get_bits(gb, s->time_increment_bits);
01934 
01935     if(s->pict_type!=FF_B_TYPE){
01936         s->last_time_base= s->time_base;
01937         s->time_base+= time_incr;
01938         s->time= s->time_base*s->avctx->time_base.den + time_increment;
01939         if(s->workaround_bugs&FF_BUG_UMP4){
01940             if(s->time < s->last_non_b_time){
01941                 /* header is not mpeg-4-compatible, broken encoder,
01942                  * trying to workaround */
01943                 s->time_base++;
01944                 s->time+= s->avctx->time_base.den;
01945             }
01946         }
01947         s->pp_time= s->time - s->last_non_b_time;
01948         s->last_non_b_time= s->time;
01949     }else{
01950         s->time= (s->last_time_base + time_incr)*s->avctx->time_base.den + time_increment;
01951         s->pb_time= s->pp_time - (s->last_non_b_time - s->time);
01952         if(s->pp_time <=s->pb_time || s->pp_time <= s->pp_time - s->pb_time || s->pp_time<=0){
01953             /* messed up order, maybe after seeking? skipping current b-frame */
01954             return FRAME_SKIPPED;
01955         }
01956         ff_mpeg4_init_direct_mv(s);
01957 
01958         if(s->t_frame==0) s->t_frame= s->pb_time;
01959         if(s->t_frame==0) s->t_frame=1; // 1/0 protection
01960         s->pp_field_time= (  ROUNDED_DIV(s->last_non_b_time, s->t_frame)
01961                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
01962         s->pb_field_time= (  ROUNDED_DIV(s->time, s->t_frame)
01963                            - ROUNDED_DIV(s->last_non_b_time - s->pp_time, s->t_frame))*2;
01964         if(!s->progressive_sequence){
01965             if(s->pp_field_time <= s->pb_field_time || s->pb_field_time <= 1)
01966                 return FRAME_SKIPPED;
01967         }
01968     }
01969 
01970     if(s->avctx->time_base.num)
01971         s->current_picture_ptr->pts= (s->time + s->avctx->time_base.num/2) / s->avctx->time_base.num;
01972     else
01973         s->current_picture_ptr->pts= AV_NOPTS_VALUE;
01974     if(s->avctx->debug&FF_DEBUG_PTS)
01975         av_log(s->avctx, AV_LOG_DEBUG, "MPEG4 PTS: %"PRId64"\n", s->current_picture_ptr->pts);
01976 
01977     check_marker(gb, "before vop_coded");
01978 
01979     /* vop coded */
01980     if (get_bits1(gb) != 1){
01981         if(s->avctx->debug&FF_DEBUG_PICT_INFO)
01982             av_log(s->avctx, AV_LOG_ERROR, "vop not coded\n");
01983         return FRAME_SKIPPED;
01984     }
01985     if (s->shape != BIN_ONLY_SHAPE && ( s->pict_type == FF_P_TYPE
01986                           || (s->pict_type == FF_S_TYPE && s->vol_sprite_usage==GMC_SPRITE))) {
01987         /* rounding type for motion estimation */
01988         s->no_rounding = get_bits1(gb);
01989     } else {
01990         s->no_rounding = 0;
01991     }
01992 //FIXME reduced res stuff
01993 
01994      if (s->shape != RECT_SHAPE) {
01995          if (s->vol_sprite_usage != 1 || s->pict_type != FF_I_TYPE) {
01996              int width, height, hor_spat_ref, ver_spat_ref;
01997 
01998              width = get_bits(gb, 13);
01999              skip_bits1(gb);   /* marker */
02000              height = get_bits(gb, 13);
02001              skip_bits1(gb);   /* marker */
02002              hor_spat_ref = get_bits(gb, 13); /* hor_spat_ref */
02003              skip_bits1(gb);   /* marker */
02004              ver_spat_ref = get_bits(gb, 13); /* ver_spat_ref */
02005          }
02006          skip_bits1(gb); /* change_CR_disable */
02007 
02008          if (get_bits1(gb) != 0) {
02009              skip_bits(gb, 8); /* constant_alpha_value */
02010          }
02011      }
02012 //FIXME complexity estimation stuff
02013 
02014      if (s->shape != BIN_ONLY_SHAPE) {
02015          skip_bits_long(gb, s->cplx_estimation_trash_i);
02016          if(s->pict_type != FF_I_TYPE)
02017             skip_bits_long(gb, s->cplx_estimation_trash_p);
02018          if(s->pict_type == FF_B_TYPE)
02019             skip_bits_long(gb, s->cplx_estimation_trash_b);
02020 
02021          s->intra_dc_threshold= mpeg4_dc_threshold[ get_bits(gb, 3) ];
02022          if(!s->progressive_sequence){
02023              s->top_field_first= get_bits1(gb);
02024              s->alternate_scan= get_bits1(gb);
02025          }else
02026              s->alternate_scan= 0;
02027      }
02028 
02029      if(s->alternate_scan){
02030          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_alternate_vertical_scan);
02031          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_alternate_vertical_scan);
02032          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_vertical_scan);
02033          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
02034      } else{
02035          ff_init_scantable(s->dsp.idct_permutation, &s->inter_scantable  , ff_zigzag_direct);
02036          ff_init_scantable(s->dsp.idct_permutation, &s->intra_scantable  , ff_zigzag_direct);
02037          ff_init_scantable(s->dsp.idct_permutation, &s->intra_h_scantable, ff_alternate_horizontal_scan);
02038          ff_init_scantable(s->dsp.idct_permutation, &s->intra_v_scantable, ff_alternate_vertical_scan);
02039      }
02040 
02041      if(s->pict_type == FF_S_TYPE && (s->vol_sprite_usage==STATIC_SPRITE || s->vol_sprite_usage==GMC_SPRITE)){
02042          mpeg4_decode_sprite_trajectory(s, gb);
02043          if(s->sprite_brightness_change) av_log(s->avctx, AV_LOG_ERROR, "sprite_brightness_change not supported\n");
02044          if(s->vol_sprite_usage==STATIC_SPRITE) av_log(s->avctx, AV_LOG_ERROR, "static sprite not supported\n");
02045      }
02046 
02047      if (s->shape != BIN_ONLY_SHAPE) {
02048          s->chroma_qscale= s->qscale = get_bits(gb, s->quant_precision);
02049          if(s->qscale==0){
02050              av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (qscale=0)\n");
02051              return -1; // makes no sense to continue, as there is nothing left from the image then
02052          }
02053 
02054          if (s->pict_type != FF_I_TYPE) {
02055              s->f_code = get_bits(gb, 3);       /* fcode_for */
02056              if(s->f_code==0){
02057                  av_log(s->avctx, AV_LOG_ERROR, "Error, header damaged or not MPEG4 header (f_code=0)\n");
02058                  return -1; // makes no sense to continue, as the MV decoding will break very quickly
02059              }
02060          }else
02061              s->f_code=1;
02062 
02063          if (s->pict_type == FF_B_TYPE) {
02064              s->b_code = get_bits(gb, 3);
02065          }else
02066              s->b_code=1;
02067 
02068          if(s->avctx->debug&FF_DEBUG_PICT_INFO){
02069              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",
02070                  s->qscale, s->f_code, s->b_code,
02071                  s->pict_type == FF_I_TYPE ? "I" : (s->pict_type == FF_P_TYPE ? "P" : (s->pict_type == FF_B_TYPE ? "B" : "S")),
02072                  gb->size_in_bits,s->progressive_sequence, s->alternate_scan, s->top_field_first,
02073                  s->quarter_sample ? "q" : "h", s->data_partitioning, s->resync_marker, s->num_sprite_warping_points,
02074                  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);
02075          }
02076 
02077          if(!s->scalability){
02078              if (s->shape!=RECT_SHAPE && s->pict_type!=FF_I_TYPE) {
02079                  skip_bits1(gb); // vop shape coding type
02080              }
02081          }else{
02082              if(s->enhancement_type){
02083                  int load_backward_shape= get_bits1(gb);
02084                  if(load_backward_shape){
02085                      av_log(s->avctx, AV_LOG_ERROR, "load backward shape isn't supported\n");
02086                  }
02087              }
02088              skip_bits(gb, 2); //ref_select_code
02089          }
02090      }
02091      /* detect buggy encoders which don't set the low_delay flag (divx4/xvid/opendivx)*/
02092      // note we cannot detect divx5 without b-frames easily (although it's buggy too)
02093      if(s->vo_type==0 && s->vol_control_parameters==0 && s->divx_version==-1 && s->picture_number==0){
02094          av_log(s->avctx, AV_LOG_WARNING, "looks like this file was encoded with (divx4/(old)xvid/opendivx) -> forcing low_delay flag\n");
02095          s->low_delay=1;
02096      }
02097 
02098      s->picture_number++; // better than pic number==0 always ;)
02099 
02100      s->y_dc_scale_table= ff_mpeg4_y_dc_scale_table; //FIXME add short header support
02101      s->c_dc_scale_table= ff_mpeg4_c_dc_scale_table;
02102 
02103      if(s->workaround_bugs&FF_BUG_EDGE){
02104          s->h_edge_pos= s->width;
02105          s->v_edge_pos= s->height;
02106      }
02107      return 0;
02108 }
02109 
02116 int ff_mpeg4_decode_picture_header(MpegEncContext * s, GetBitContext *gb)
02117 {
02118     int startcode, v;
02119 
02120     /* search next start code */
02121     align_get_bits(gb);
02122 
02123     if(s->codec_tag == AV_RL32("WV1F") && show_bits(gb, 24) == 0x575630){
02124         skip_bits(gb, 24);
02125         if(get_bits(gb, 8) == 0xF0)
02126             goto end;
02127     }
02128 
02129     startcode = 0xff;
02130     for(;;) {
02131         if(get_bits_count(gb) >= gb->size_in_bits){
02132             if(gb->size_in_bits==8 && (s->divx_version>=0 || s->xvid_build>=0)){
02133                 av_log(s->avctx, AV_LOG_WARNING, "frame skip %d\n", gb->size_in_bits);
02134                 return FRAME_SKIPPED; //divx bug
02135             }else
02136                 return -1; //end of stream
02137         }
02138 
02139         /* use the bits after the test */
02140         v = get_bits(gb, 8);
02141         startcode = ((startcode << 8) | v) & 0xffffffff;
02142 
02143         if((startcode&0xFFFFFF00) != 0x100)
02144             continue; //no startcode
02145 
02146         if(s->avctx->debug&FF_DEBUG_STARTCODE){
02147             av_log(s->avctx, AV_LOG_DEBUG, "startcode: %3X ", startcode);
02148             if     (startcode<=0x11F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Start");
02149             else if(startcode<=0x12F) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Layer Start");
02150             else if(startcode<=0x13F) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
02151             else if(startcode<=0x15F) av_log(s->avctx, AV_LOG_DEBUG, "FGS bp start");
02152             else if(startcode<=0x1AF) av_log(s->avctx, AV_LOG_DEBUG, "Reserved");
02153             else if(startcode==0x1B0) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq Start");
02154             else if(startcode==0x1B1) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Seq End");
02155             else if(startcode==0x1B2) av_log(s->avctx, AV_LOG_DEBUG, "User Data");
02156             else if(startcode==0x1B3) av_log(s->avctx, AV_LOG_DEBUG, "Group of VOP start");
02157             else if(startcode==0x1B4) av_log(s->avctx, AV_LOG_DEBUG, "Video Session Error");
02158             else if(startcode==0x1B5) av_log(s->avctx, AV_LOG_DEBUG, "Visual Object Start");
02159             else if(startcode==0x1B6) av_log(s->avctx, AV_LOG_DEBUG, "Video Object Plane start");
02160             else if(startcode==0x1B7) av_log(s->avctx, AV_LOG_DEBUG, "slice start");
02161             else if(startcode==0x1B8) av_log(s->avctx, AV_LOG_DEBUG, "extension start");
02162             else if(startcode==0x1B9) av_log(s->avctx, AV_LOG_DEBUG, "fgs start");
02163             else if(startcode==0x1BA) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object start");
02164             else if(startcode==0x1BB) av_log(s->avctx, AV_LOG_DEBUG, "FBA Object Plane start");
02165             else if(startcode==0x1BC) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object start");
02166             else if(startcode==0x1BD) av_log(s->avctx, AV_LOG_DEBUG, "Mesh Object Plane start");
02167             else if(startcode==0x1BE) av_log(s->avctx, AV_LOG_DEBUG, "Still Texture Object start");
02168             else if(startcode==0x1BF) av_log(s->avctx, AV_LOG_DEBUG, "Texture Spatial Layer start");
02169             else if(startcode==0x1C0) av_log(s->avctx, AV_LOG_DEBUG, "Texture SNR Layer start");
02170             else if(startcode==0x1C1) av_log(s->avctx, AV_LOG_DEBUG, "Texture Tile start");
02171             else if(startcode==0x1C2) av_log(s->avctx, AV_LOG_DEBUG, "Texture Shape Layer start");
02172             else if(startcode==0x1C3) av_log(s->avctx, AV_LOG_DEBUG, "stuffing start");
02173             else if(startcode<=0x1C5) av_log(s->avctx, AV_LOG_DEBUG, "reserved");
02174             else if(startcode<=0x1FF) av_log(s->avctx, AV_LOG_DEBUG, "System start");
02175             av_log(s->avctx, AV_LOG_DEBUG, " at %d\n", get_bits_count(gb));
02176         }
02177 
02178         if(startcode >= 0x120 && startcode <= 0x12F){
02179             if(decode_vol_header(s, gb) < 0)
02180                 return -1;
02181         }
02182         else if(startcode == USER_DATA_STARTCODE){
02183             decode_user_data(s, gb);
02184         }
02185         else if(startcode == GOP_STARTCODE){
02186             mpeg4_decode_gop_header(s, gb);
02187         }
02188         else if(startcode == VOP_STARTCODE){
02189             break;
02190         }
02191 
02192         align_get_bits(gb);
02193         startcode = 0xff;
02194     }
02195 end:
02196     if(s->flags& CODEC_FLAG_LOW_DELAY)
02197         s->low_delay=1;
02198     s->avctx->has_b_frames= !s->low_delay;
02199     return decode_vop_header(s, gb);
02200 }
02201 
02202 static av_cold int decode_init(AVCodecContext *avctx)
02203 {
02204     MpegEncContext *s = avctx->priv_data;
02205     int ret;
02206     static int done = 0;
02207 
02208     s->divx_version=
02209     s->divx_build=
02210     s->xvid_build=
02211     s->lavc_build= -1;
02212 
02213     if((ret=ff_h263_decode_init(avctx)) < 0)
02214         return ret;
02215 
02216     if (!done) {
02217         done = 1;
02218 
02219         init_rl(&ff_mpeg4_rl_intra, ff_mpeg4_static_rl_table_store[0]);
02220         init_rl(&rvlc_rl_inter, ff_mpeg4_static_rl_table_store[1]);
02221         init_rl(&rvlc_rl_intra, ff_mpeg4_static_rl_table_store[2]);
02222         INIT_VLC_RL(ff_mpeg4_rl_intra, 554);
02223         INIT_VLC_RL(rvlc_rl_inter, 1072);
02224         INIT_VLC_RL(rvlc_rl_intra, 1072);
02225         INIT_VLC_STATIC(&dc_lum, DC_VLC_BITS, 10 /* 13 */,
02226                  &ff_mpeg4_DCtab_lum[0][1], 2, 1,
02227                  &ff_mpeg4_DCtab_lum[0][0], 2, 1, 512);
02228         INIT_VLC_STATIC(&dc_chrom, DC_VLC_BITS, 10 /* 13 */,
02229                  &ff_mpeg4_DCtab_chrom[0][1], 2, 1,
02230                  &ff_mpeg4_DCtab_chrom[0][0], 2, 1, 512);
02231         INIT_VLC_STATIC(&sprite_trajectory, SPRITE_TRAJ_VLC_BITS, 15,
02232                  &sprite_trajectory_tab[0][1], 4, 2,
02233                  &sprite_trajectory_tab[0][0], 4, 2, 128);
02234         INIT_VLC_STATIC(&mb_type_b_vlc, MB_TYPE_B_VLC_BITS, 4,
02235                  &mb_type_b_tab[0][1], 2, 1,
02236                  &mb_type_b_tab[0][0], 2, 1, 16);
02237     }
02238 
02239     s->h263_pred = 1;
02240     s->low_delay = 0; //default, might be overriden in the vol header during header parsing
02241     s->decode_mb= mpeg4_decode_mb;
02242     s->time_increment_bits = 4; /* default value for broken headers */
02243     avctx->chroma_sample_location = AVCHROMA_LOC_LEFT;
02244 
02245     return 0;
02246 }
02247 
02248 AVCodec ff_mpeg4_decoder = {
02249     "mpeg4",
02250     AVMEDIA_TYPE_VIDEO,
02251     CODEC_ID_MPEG4,
02252     sizeof(MpegEncContext),
02253     decode_init,
02254     NULL,
02255     ff_h263_decode_end,
02256     ff_h263_decode_frame,
02257     CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_FRAME_THREADS,
02258     .flush= ff_mpeg_flush,
02259     .max_lowres= 3,
02260     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2"),
02261     .pix_fmts= ff_hwaccel_pixfmt_list_420,
02262     .update_thread_context= ONLY_IF_THREADS_ENABLED(ff_mpeg_update_thread_context)
02263 };
02264 
02265 
02266 #if CONFIG_MPEG4_VDPAU_DECODER
02267 AVCodec ff_mpeg4_vdpau_decoder = {
02268     "mpeg4_vdpau",
02269     AVMEDIA_TYPE_VIDEO,
02270     CODEC_ID_MPEG4,
02271     sizeof(MpegEncContext),
02272     decode_init,
02273     NULL,
02274     ff_h263_decode_end,
02275     ff_h263_decode_frame,
02276     CODEC_CAP_DR1 | CODEC_CAP_TRUNCATED | CODEC_CAP_DELAY | CODEC_CAP_HWACCEL_VDPAU,
02277     .long_name= NULL_IF_CONFIG_SMALL("MPEG-4 part 2 (VDPAU)"),
02278     .pix_fmts= (const enum PixelFormat[]){PIX_FMT_VDPAU_MPEG4, PIX_FMT_NONE},
02279 };
02280 #endif