+static int decode_slice(MpegEncContext *s){
+ const int part_mask= s->partitioned_frame ? (AC_END|AC_ERROR) : 0x7F;
+ s->last_resync_gb= s->gb;
+ s->first_slice_line= 1;
+
+ s->resync_mb_x= s->mb_x;
+ s->resync_mb_y= s->mb_y;
+
+ s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
+ s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
+
+ if(s->partitioned_frame){
+ const int qscale= s->qscale;
+
+ if(s->codec_id==CODEC_ID_MPEG4){
+ if(ff_mpeg4_decode_partitions(s) < 0)
+ return -1;
+ }
+
+ /* restore variables which were modified */
+ s->first_slice_line=1;
+ s->mb_x= s->resync_mb_x;
+ s->mb_y= s->resync_mb_y;
+ s->qscale= qscale;
+ s->y_dc_scale= s->y_dc_scale_table[ s->qscale ];
+ s->c_dc_scale= s->c_dc_scale_table[ s->qscale ];
+ }
+
+ for(; s->mb_y < s->mb_height; s->mb_y++) {
+ /* per-row end of slice checks */
+ if(s->msmpeg4_version){
+ if(s->resync_mb_y + s->slice_height == s->mb_y){
+ ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
+
+ return 0;
+ }
+ }
+
+ if(s->msmpeg4_version==1){
+ s->last_dc[0]=
+ s->last_dc[1]=
+ s->last_dc[2]= 128;
+ }
+
+ ff_init_block_index(s);
+ for(; s->mb_x < s->mb_width; s->mb_x++) {
+ int ret;
+
+ ff_update_block_index(s);
+
+ if(s->resync_mb_x == s->mb_x && s->resync_mb_y+1 == s->mb_y){
+ s->first_slice_line=0;
+ }
+
+ /* DCT & quantize */
+ s->dsp.clear_blocks(s->block[0]);
+
+ s->mv_dir = MV_DIR_FORWARD;
+ s->mv_type = MV_TYPE_16X16;
+// s->mb_skiped = 0;
+//printf("%d %d %06X\n", ret, get_bits_count(&s->gb), show_bits(&s->gb, 24));
+ ret= s->decode_mb(s, s->block);
+
+ if (s->pict_type!=B_TYPE)
+ ff_h263_update_motion_val(s);
+
+ if(ret<0){
+ const int xy= s->mb_x + s->mb_y*s->mb_stride;
+ if(ret==SLICE_END){
+ MPV_decode_mb(s, s->block);
+
+//printf("%d %d %d %06X\n", s->mb_x, s->mb_y, s->gb.size*8 - get_bits_count(&s->gb), show_bits(&s->gb, 24));
+ ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
+
+ s->padding_bug_score--;
+
+ if(++s->mb_x >= s->mb_width){
+ s->mb_x=0;
+ ff_draw_horiz_band(s, s->mb_y*16, 16);
+ s->mb_y++;
+ }
+ return 0;
+ }else if(ret==SLICE_NOEND){
+ fprintf(stderr,"Slice mismatch at MB: %d\n", xy);
+ ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x+1, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
+ return -1;
+ }
+ fprintf(stderr,"Error at MB: %d\n", xy);
+ ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_ERROR|DC_ERROR|MV_ERROR)&part_mask);
+
+ return -1;
+ }
+
+ MPV_decode_mb(s, s->block);
+ }
+
+ ff_draw_horiz_band(s, s->mb_y*16, 16);
+
+ s->mb_x= 0;
+ }
+
+ assert(s->mb_x==0 && s->mb_y==s->mb_height);
+
+ /* try to detect the padding bug */
+ if( s->codec_id==CODEC_ID_MPEG4
+ && (s->workaround_bugs&FF_BUG_AUTODETECT)
+ && s->gb.size_in_bits - get_bits_count(&s->gb) >=0
+ && s->gb.size_in_bits - get_bits_count(&s->gb) < 48
+// && !s->resync_marker
+ && !s->data_partitioning){
+
+ const int bits_count= get_bits_count(&s->gb);
+ const int bits_left = s->gb.size_in_bits - bits_count;
+
+ if(bits_left==0){
+ s->padding_bug_score+=16;
+ }else if(bits_left>8){
+ s->padding_bug_score++;
+ } else if(bits_left != 1){
+ int v= show_bits(&s->gb, 8);
+ v|= 0x7F >> (7-(bits_count&7));
+
+ if(v==0x7F)
+ s->padding_bug_score--;
+ else
+ s->padding_bug_score++;
+ }
+ }
+
+ // handle formats which dont have unique end markers
+ if(s->msmpeg4_version || (s->workaround_bugs&FF_BUG_NO_PADDING)){ //FIXME perhaps solve this more cleanly
+ int left= s->gb.size_in_bits - get_bits_count(&s->gb);
+ int max_extra=7;
+
+ /* no markers in M$ crap */
+ if(s->msmpeg4_version && s->pict_type==I_TYPE)
+ max_extra+= 17;
+
+ /* buggy padding but the frame should still end approximately at the bitstream end */
+ if((s->workaround_bugs&FF_BUG_NO_PADDING) && s->error_resilience>=3)
+ max_extra+= 48;
+ else if((s->workaround_bugs&FF_BUG_NO_PADDING))
+ max_extra+= 256*256*256*64;
+
+ if(left>max_extra){
+ fprintf(stderr, "discarding %d junk bits at end, next would be %X\n", left, show_bits(&s->gb, 24));
+ }
+ else if(left<0){
+ fprintf(stderr, "overreading %d bits\n", -left);
+ }else
+ ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x-1, s->mb_y, AC_END|DC_END|MV_END);
+
+ return 0;
+ }
+
+ fprintf(stderr, "slice end not reached but screenspace end (%d left %06X, score= %d)\n",
+ s->gb.size_in_bits - get_bits_count(&s->gb),
+ show_bits(&s->gb, 24), s->padding_bug_score);
+
+ ff_er_add_slice(s, s->resync_mb_x, s->resync_mb_y, s->mb_x, s->mb_y, (AC_END|DC_END|MV_END)&part_mask);
+
+ return -1;
+}
+
+/**
+ * finds the end of the current frame in the bitstream.
+ * @return the position of the first byte of the next frame, or -1
+ */
+static int mpeg4_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
+ ParseContext *pc= &s->parse_context;
+ int vop_found, i;
+ uint32_t state;
+
+ vop_found= pc->frame_start_found;
+ state= pc->state;
+
+ i=0;
+ if(!vop_found){
+ for(i=0; i<buf_size; i++){
+ state= (state<<8) | buf[i];
+ if(state == 0x1B6){
+ i++;
+ vop_found=1;
+ break;
+ }
+ }
+ }
+
+ if(vop_found){
+ for(; i<buf_size; i++){
+ state= (state<<8) | buf[i];
+ if((state&0xFFFFFF00) == 0x100){
+ pc->frame_start_found=0;
+ pc->state=-1;
+ return i-3;
+ }
+ }
+ }
+ pc->frame_start_found= vop_found;
+ pc->state= state;
+ return END_NOT_FOUND;
+}
+
+static int h263_find_frame_end(MpegEncContext *s, uint8_t *buf, int buf_size){
+ ParseContext *pc= &s->parse_context;
+ int vop_found, i;
+ uint32_t state;
+
+ vop_found= pc->frame_start_found;
+ state= pc->state;
+
+ i=0;
+ if(!vop_found){
+ for(i=0; i<buf_size; i++){
+ state= (state<<8) | buf[i];
+ if(state>>(32-22) == 0x20){
+ i++;
+ vop_found=1;
+ break;
+ }
+ }
+ }
+
+ if(vop_found){
+ for(; i<buf_size; i++){
+ state= (state<<8) | buf[i];
+ if(state>>(32-22) == 0x20){
+ pc->frame_start_found=0;
+ pc->state=-1;
+ return i-3;
+ }
+ }
+ }
+ pc->frame_start_found= vop_found;
+ pc->state= state;
+
+ return END_NOT_FOUND;
+}
+
+int ff_h263_decode_frame(AVCodecContext *avctx,