yading@10: /*
yading@10:  * ITU H263 bitstream decoder
yading@10:  * Copyright (c) 2000,2001 Fabrice Bellard
yading@10:  * H263+ support.
yading@10:  * Copyright (c) 2001 Juan J. Sierralta P
yading@10:  * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * h263 decoder.
yading@10:  */
yading@10: 
yading@10: #define UNCHECKED_BITSTREAM_READER 1
yading@10: 
yading@10: //#define DEBUG
yading@10: #include <limits.h>
yading@10: 
yading@10: #include "libavutil/internal.h"
yading@10: #include "libavutil/mathematics.h"
yading@10: #include "avcodec.h"
yading@10: #include "mpegvideo.h"
yading@10: #include "h263.h"
yading@10: #include "mathops.h"
yading@10: #include "unary.h"
yading@10: #include "flv.h"
yading@10: #include "mpeg4video.h"
yading@10: 
yading@10: // The defines below define the number of bits that are read at once for
yading@10: // reading vlc values. Changing these may improve speed and data cache needs
yading@10: // be aware though that decreasing them may need the number of stages that is
yading@10: // passed to get_vlc* to be increased.
yading@10: #define MV_VLC_BITS 9
yading@10: #define H263_MBTYPE_B_VLC_BITS 6
yading@10: #define CBPC_B_VLC_BITS 3
yading@10: 
yading@10: static const int h263_mb_type_b_map[15]= {
yading@10:     MB_TYPE_DIRECT2 | MB_TYPE_L0L1,
yading@10:     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP,
yading@10:     MB_TYPE_DIRECT2 | MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT,
yading@10:                       MB_TYPE_L0                                 | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L0   | MB_TYPE_CBP                 | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L0   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L1                                 | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L1   | MB_TYPE_CBP                 | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L1   | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L0L1                               | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L0L1 | MB_TYPE_CBP                 | MB_TYPE_16x16,
yading@10:                       MB_TYPE_L0L1 | MB_TYPE_CBP | MB_TYPE_QUANT | MB_TYPE_16x16,
yading@10:     0, //stuffing
yading@10:     MB_TYPE_INTRA4x4                | MB_TYPE_CBP,
yading@10:     MB_TYPE_INTRA4x4                | MB_TYPE_CBP | MB_TYPE_QUANT,
yading@10: };
yading@10: 
yading@10: void ff_h263_show_pict_info(MpegEncContext *s){
yading@10:     if(s->avctx->debug&FF_DEBUG_PICT_INFO){
yading@10:     av_log(s->avctx, AV_LOG_DEBUG, "qp:%d %c size:%d rnd:%d%s%s%s%s%s%s%s%s%s %d/%d\n",
yading@10:          s->qscale, av_get_picture_type_char(s->pict_type),
yading@10:          s->gb.size_in_bits, 1-s->no_rounding,
yading@10:          s->obmc ? " AP" : "",
yading@10:          s->umvplus ? " UMV" : "",
yading@10:          s->h263_long_vectors ? " LONG" : "",
yading@10:          s->h263_plus ? " +" : "",
yading@10:          s->h263_aic ? " AIC" : "",
yading@10:          s->alt_inter_vlc ? " AIV" : "",
yading@10:          s->modified_quant ? " MQ" : "",
yading@10:          s->loop_filter ? " LOOP" : "",
yading@10:          s->h263_slice_structured ? " SS" : "",
yading@10:          s->avctx->time_base.den, s->avctx->time_base.num
yading@10:     );
yading@10:     }
yading@10: }
yading@10: 
yading@10: /***********************************************/
yading@10: /* decoding */
yading@10: 
yading@10: VLC ff_h263_intra_MCBPC_vlc;
yading@10: VLC ff_h263_inter_MCBPC_vlc;
yading@10: VLC ff_h263_cbpy_vlc;
yading@10: static VLC mv_vlc;
yading@10: static VLC h263_mbtype_b_vlc;
yading@10: static VLC cbpc_b_vlc;
yading@10: 
yading@10: /* init vlcs */
yading@10: 
yading@10: /* XXX: find a better solution to handle static init */
yading@10: void ff_h263_decode_init_vlc(void)
yading@10: {
yading@10:     static volatile int done = 0;
yading@10: 
yading@10:     if (!done) {
yading@10:         INIT_VLC_STATIC(&ff_h263_intra_MCBPC_vlc, INTRA_MCBPC_VLC_BITS, 9,
yading@10:                  ff_h263_intra_MCBPC_bits, 1, 1,
yading@10:                  ff_h263_intra_MCBPC_code, 1, 1, 72);
yading@10:         INIT_VLC_STATIC(&ff_h263_inter_MCBPC_vlc, INTER_MCBPC_VLC_BITS, 28,
yading@10:                  ff_h263_inter_MCBPC_bits, 1, 1,
yading@10:                  ff_h263_inter_MCBPC_code, 1, 1, 198);
yading@10:         INIT_VLC_STATIC(&ff_h263_cbpy_vlc, CBPY_VLC_BITS, 16,
yading@10:                  &ff_h263_cbpy_tab[0][1], 2, 1,
yading@10:                  &ff_h263_cbpy_tab[0][0], 2, 1, 64);
yading@10:         INIT_VLC_STATIC(&mv_vlc, MV_VLC_BITS, 33,
yading@10:                  &ff_mvtab[0][1], 2, 1,
yading@10:                  &ff_mvtab[0][0], 2, 1, 538);
yading@10:         ff_init_rl(&ff_h263_rl_inter, ff_h263_static_rl_table_store[0]);
yading@10:         ff_init_rl(&ff_rl_intra_aic, ff_h263_static_rl_table_store[1]);
yading@10:         INIT_VLC_RL(ff_h263_rl_inter, 554);
yading@10:         INIT_VLC_RL(ff_rl_intra_aic, 554);
yading@10:         INIT_VLC_STATIC(&h263_mbtype_b_vlc, H263_MBTYPE_B_VLC_BITS, 15,
yading@10:                  &ff_h263_mbtype_b_tab[0][1], 2, 1,
yading@10:                  &ff_h263_mbtype_b_tab[0][0], 2, 1, 80);
yading@10:         INIT_VLC_STATIC(&cbpc_b_vlc, CBPC_B_VLC_BITS, 4,
yading@10:                  &ff_cbpc_b_tab[0][1], 2, 1,
yading@10:                  &ff_cbpc_b_tab[0][0], 2, 1, 8);
yading@10:         done = 1;
yading@10:     }
yading@10: }
yading@10: 
yading@10: int ff_h263_decode_mba(MpegEncContext *s)
yading@10: {
yading@10:     int i, mb_pos;
yading@10: 
yading@10:     for(i=0; i<6; i++){
yading@10:         if(s->mb_num-1 <= ff_mba_max[i]) break;
yading@10:     }
yading@10:     mb_pos= get_bits(&s->gb, ff_mba_length[i]);
yading@10:     s->mb_x= mb_pos % s->mb_width;
yading@10:     s->mb_y= mb_pos / s->mb_width;
yading@10: 
yading@10:     return mb_pos;
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Decode the group of blocks header or slice header.
yading@10:  * @return <0 if an error occurred
yading@10:  */
yading@10: static int h263_decode_gob_header(MpegEncContext *s)
yading@10: {
yading@10:     unsigned int val, gob_number;
yading@10:     int left;
yading@10: 
yading@10:     /* Check for GOB Start Code */
yading@10:     val = show_bits(&s->gb, 16);
yading@10:     if(val)
yading@10:         return -1;
yading@10: 
yading@10:         /* We have a GBSC probably with GSTUFF */
yading@10:     skip_bits(&s->gb, 16); /* Drop the zeros */
yading@10:     left= get_bits_left(&s->gb);
yading@10:     //MN: we must check the bits left or we might end in a infinite loop (or segfault)
yading@10:     for(;left>13; left--){
yading@10:         if(get_bits1(&s->gb)) break; /* Seek the '1' bit */
yading@10:     }
yading@10:     if(left<=13)
yading@10:         return -1;
yading@10: 
yading@10:     if(s->h263_slice_structured){
yading@10:         if(get_bits1(&s->gb)==0)
yading@10:             return -1;
yading@10: 
yading@10:         ff_h263_decode_mba(s);
yading@10: 
yading@10:         if(s->mb_num > 1583)
yading@10:             if(get_bits1(&s->gb)==0)
yading@10:                 return -1;
yading@10: 
yading@10:         s->qscale = get_bits(&s->gb, 5); /* SQUANT */
yading@10:         if(get_bits1(&s->gb)==0)
yading@10:             return -1;
yading@10:         skip_bits(&s->gb, 2); /* GFID */
yading@10:     }else{
yading@10:         gob_number = get_bits(&s->gb, 5); /* GN */
yading@10:         s->mb_x= 0;
yading@10:         s->mb_y= s->gob_index* gob_number;
yading@10:         skip_bits(&s->gb, 2); /* GFID */
yading@10:         s->qscale = get_bits(&s->gb, 5); /* GQUANT */
yading@10:     }
yading@10: 
yading@10:     if(s->mb_y >= s->mb_height)
yading@10:         return -1;
yading@10: 
yading@10:     if(s->qscale==0)
yading@10:         return -1;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Find the next resync_marker.
yading@10:  * @param p pointer to buffer to scan
yading@10:  * @param end pointer to the end of the buffer
yading@10:  * @return pointer to the next resync_marker, or end if none was found
yading@10:  */
yading@10: const uint8_t *ff_h263_find_resync_marker(MpegEncContext *s, const uint8_t *av_restrict p, const uint8_t *av_restrict end)
yading@10: {
yading@10:     av_assert2(p < end);
yading@10: 
yading@10:     end-=2;
yading@10:     p++;
yading@10:     if(s->resync_marker){
yading@10:         int prefix_len = ff_mpeg4_get_video_packet_prefix_length(s);
yading@10:         for(;p<end; p+=2){
yading@10:             if(!*p){
yading@10:                 if      (!p[-1] && ((p[1] >> (23-prefix_len)) == 1)) return p - 1;
yading@10:                 else if (!p[ 1] && ((p[2] >> (23-prefix_len)) == 1)) return p;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10:     return end+2;
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Decode the group of blocks / video packet header.
yading@10:  * @return bit position of the resync_marker, or <0 if none was found
yading@10:  */
yading@10: int ff_h263_resync(MpegEncContext *s){
yading@10:     int left, pos, ret;
yading@10: 
yading@10:     if(s->codec_id==AV_CODEC_ID_MPEG4){
yading@10:         skip_bits1(&s->gb);
yading@10:         align_get_bits(&s->gb);
yading@10:     }
yading@10: 
yading@10:     if(show_bits(&s->gb, 16)==0){
yading@10:         pos= get_bits_count(&s->gb);
yading@10:         if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
yading@10:             ret= ff_mpeg4_decode_video_packet_header(s);
yading@10:         else
yading@10:             ret= h263_decode_gob_header(s);
yading@10:         if(ret>=0)
yading@10:             return pos;
yading@10:     }
yading@10:     //OK, it's not where it is supposed to be ...
yading@10:     s->gb= s->last_resync_gb;
yading@10:     align_get_bits(&s->gb);
yading@10:     left= get_bits_left(&s->gb);
yading@10: 
yading@10:     for(;left>16+1+5+5; left-=8){
yading@10:         if(show_bits(&s->gb, 16)==0){
yading@10:             GetBitContext bak= s->gb;
yading@10: 
yading@10:             pos= get_bits_count(&s->gb);
yading@10:             if(CONFIG_MPEG4_DECODER && s->codec_id==AV_CODEC_ID_MPEG4)
yading@10:                 ret= ff_mpeg4_decode_video_packet_header(s);
yading@10:             else
yading@10:                 ret= h263_decode_gob_header(s);
yading@10:             if(ret>=0)
yading@10:                 return pos;
yading@10: 
yading@10:             s->gb= bak;
yading@10:         }
yading@10:         skip_bits(&s->gb, 8);
yading@10:     }
yading@10: 
yading@10:     return -1;
yading@10: }
yading@10: 
yading@10: int ff_h263_decode_motion(MpegEncContext * s, int pred, int f_code)
yading@10: {
yading@10:     int code, val, sign, shift;
yading@10:     code = get_vlc2(&s->gb, mv_vlc.table, MV_VLC_BITS, 2);
yading@10: 
yading@10:     if (code == 0)
yading@10:         return pred;
yading@10:     if (code < 0)
yading@10:         return 0xffff;
yading@10: 
yading@10:     sign = get_bits1(&s->gb);
yading@10:     shift = f_code - 1;
yading@10:     val = code;
yading@10:     if (shift) {
yading@10:         val = (val - 1) << shift;
yading@10:         val |= get_bits(&s->gb, shift);
yading@10:         val++;
yading@10:     }
yading@10:     if (sign)
yading@10:         val = -val;
yading@10:     val += pred;
yading@10: 
yading@10:     /* modulo decoding */
yading@10:     if (!s->h263_long_vectors) {
yading@10:         val = sign_extend(val, 5 + f_code);
yading@10:     } else {
yading@10:         /* horrible h263 long vector mode */
yading@10:         if (pred < -31 && val < -63)
yading@10:             val += 64;
yading@10:         if (pred > 32 && val > 63)
yading@10:             val -= 64;
yading@10: 
yading@10:     }
yading@10:     return val;
yading@10: }
yading@10: 
yading@10: 
yading@10: /* Decode RVLC of H.263+ UMV */
yading@10: static int h263p_decode_umotion(MpegEncContext * s, int pred)
yading@10: {
yading@10:    int code = 0, sign;
yading@10: 
yading@10:    if (get_bits1(&s->gb)) /* Motion difference = 0 */
yading@10:       return pred;
yading@10: 
yading@10:    code = 2 + get_bits1(&s->gb);
yading@10: 
yading@10:    while (get_bits1(&s->gb))
yading@10:    {
yading@10:       code <<= 1;
yading@10:       code += get_bits1(&s->gb);
yading@10:    }
yading@10:    sign = code & 1;
yading@10:    code >>= 1;
yading@10: 
yading@10:    code = (sign) ? (pred - code) : (pred + code);
yading@10:    av_dlog(s->avctx,"H.263+ UMV Motion = %d\n", code);
yading@10:    return code;
yading@10: 
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * read the next MVs for OBMC. yes this is a ugly hack, feel free to send a patch :)
yading@10:  */
yading@10: static void preview_obmc(MpegEncContext *s){
yading@10:     GetBitContext gb= s->gb;
yading@10: 
yading@10:     int cbpc, i, pred_x, pred_y, mx, my;
yading@10:     int16_t *mot_val;
yading@10:     const int xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
yading@10:     const int stride= s->b8_stride*2;
yading@10: 
yading@10:     for(i=0; i<4; i++)
yading@10:         s->block_index[i]+= 2;
yading@10:     for(i=4; i<6; i++)
yading@10:         s->block_index[i]+= 1;
yading@10:     s->mb_x++;
yading@10: 
yading@10:     av_assert2(s->pict_type == AV_PICTURE_TYPE_P);
yading@10: 
yading@10:     do{
yading@10:         if (get_bits1(&s->gb)) {
yading@10:             /* skip mb */
yading@10:             mot_val = s->current_picture.motion_val[0][s->block_index[0]];
yading@10:             mot_val[0       ]= mot_val[2       ]=
yading@10:             mot_val[0+stride]= mot_val[2+stride]= 0;
yading@10:             mot_val[1       ]= mot_val[3       ]=
yading@10:             mot_val[1+stride]= mot_val[3+stride]= 0;
yading@10: 
yading@10:             s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
yading@10:             goto end;
yading@10:         }
yading@10:         cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
yading@10:     }while(cbpc == 20);
yading@10: 
yading@10:     if(cbpc & 4){
yading@10:         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
yading@10:     }else{
yading@10:         get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
yading@10:         if (cbpc & 8) {
yading@10:             if(s->modified_quant){
yading@10:                 if(get_bits1(&s->gb)) skip_bits(&s->gb, 1);
yading@10:                 else                  skip_bits(&s->gb, 5);
yading@10:             }else
yading@10:                 skip_bits(&s->gb, 2);
yading@10:         }
yading@10: 
yading@10:         if ((cbpc & 16) == 0) {
yading@10:                 s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
yading@10:                 /* 16x16 motion prediction */
yading@10:                 mot_val= ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
yading@10:                 if (s->umvplus)
yading@10:                    mx = h263p_decode_umotion(s, pred_x);
yading@10:                 else
yading@10:                    mx = ff_h263_decode_motion(s, pred_x, 1);
yading@10: 
yading@10:                 if (s->umvplus)
yading@10:                    my = h263p_decode_umotion(s, pred_y);
yading@10:                 else
yading@10:                    my = ff_h263_decode_motion(s, pred_y, 1);
yading@10: 
yading@10:                 mot_val[0       ]= mot_val[2       ]=
yading@10:                 mot_val[0+stride]= mot_val[2+stride]= mx;
yading@10:                 mot_val[1       ]= mot_val[3       ]=
yading@10:                 mot_val[1+stride]= mot_val[3+stride]= my;
yading@10:         } else {
yading@10:             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
yading@10:             for(i=0;i<4;i++) {
yading@10:                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
yading@10:                 if (s->umvplus)
yading@10:                   mx = h263p_decode_umotion(s, pred_x);
yading@10:                 else
yading@10:                   mx = ff_h263_decode_motion(s, pred_x, 1);
yading@10: 
yading@10:                 if (s->umvplus)
yading@10:                   my = h263p_decode_umotion(s, pred_y);
yading@10:                 else
yading@10:                   my = ff_h263_decode_motion(s, pred_y, 1);
yading@10:                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
yading@10:                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
yading@10:                 mot_val[0] = mx;
yading@10:                 mot_val[1] = my;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10: end:
yading@10: 
yading@10:     for(i=0; i<4; i++)
yading@10:         s->block_index[i]-= 2;
yading@10:     for(i=4; i<6; i++)
yading@10:         s->block_index[i]-= 1;
yading@10:     s->mb_x--;
yading@10: 
yading@10:     s->gb= gb;
yading@10: }
yading@10: 
yading@10: static void h263_decode_dquant(MpegEncContext *s){
yading@10:     static const int8_t quant_tab[4] = { -1, -2, 1, 2 };
yading@10: 
yading@10:     if(s->modified_quant){
yading@10:         if(get_bits1(&s->gb))
yading@10:             s->qscale= ff_modified_quant_tab[get_bits1(&s->gb)][ s->qscale ];
yading@10:         else
yading@10:             s->qscale= get_bits(&s->gb, 5);
yading@10:     }else
yading@10:         s->qscale += quant_tab[get_bits(&s->gb, 2)];
yading@10:     ff_set_qscale(s, s->qscale);
yading@10: }
yading@10: 
yading@10: static int h263_decode_block(MpegEncContext * s, int16_t * block,
yading@10:                              int n, int coded)
yading@10: {
yading@10:     int code, level, i, j, last, run;
yading@10:     RLTable *rl = &ff_h263_rl_inter;
yading@10:     const uint8_t *scan_table;
yading@10:     GetBitContext gb= s->gb;
yading@10: 
yading@10:     scan_table = s->intra_scantable.permutated;
yading@10:     if (s->h263_aic && s->mb_intra) {
yading@10:         rl = &ff_rl_intra_aic;
yading@10:         i = 0;
yading@10:         if (s->ac_pred) {
yading@10:             if (s->h263_aic_dir)
yading@10:                 scan_table = s->intra_v_scantable.permutated; /* left */
yading@10:             else
yading@10:                 scan_table = s->intra_h_scantable.permutated; /* top */
yading@10:         }
yading@10:     } else if (s->mb_intra) {
yading@10:         /* DC coef */
yading@10:         if(s->codec_id == AV_CODEC_ID_RV10){
yading@10: #if CONFIG_RV10_DECODER
yading@10:           if (s->rv10_version == 3 && s->pict_type == AV_PICTURE_TYPE_I) {
yading@10:             int component, diff;
yading@10:             component = (n <= 3 ? 0 : n - 4 + 1);
yading@10:             level = s->last_dc[component];
yading@10:             if (s->rv10_first_dc_coded[component]) {
yading@10:                 diff = ff_rv_decode_dc(s, n);
yading@10:                 if (diff == 0xffff)
yading@10:                     return -1;
yading@10:                 level += diff;
yading@10:                 level = level & 0xff; /* handle wrap round */
yading@10:                 s->last_dc[component] = level;
yading@10:             } else {
yading@10:                 s->rv10_first_dc_coded[component] = 1;
yading@10:             }
yading@10:           } else {
yading@10:                 level = get_bits(&s->gb, 8);
yading@10:                 if (level == 255)
yading@10:                     level = 128;
yading@10:           }
yading@10: #endif
yading@10:         }else{
yading@10:             level = get_bits(&s->gb, 8);
yading@10:             if((level&0x7F) == 0){
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y);
yading@10:                 if(s->err_recognition & (AV_EF_BITSTREAM|AV_EF_COMPLIANT))
yading@10:                     return -1;
yading@10:             }
yading@10:             if (level == 255)
yading@10:                 level = 128;
yading@10:         }
yading@10:         block[0] = level;
yading@10:         i = 1;
yading@10:     } else {
yading@10:         i = 0;
yading@10:     }
yading@10:     if (!coded) {
yading@10:         if (s->mb_intra && s->h263_aic)
yading@10:             goto not_coded;
yading@10:         s->block_last_index[n] = i - 1;
yading@10:         return 0;
yading@10:     }
yading@10: retry:
yading@10:     for(;;) {
yading@10:         code = get_vlc2(&s->gb, rl->vlc.table, TEX_VLC_BITS, 2);
yading@10:         if (code < 0){
yading@10:             av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y);
yading@10:             return -1;
yading@10:         }
yading@10:         if (code == rl->n) {
yading@10:             /* escape */
yading@10:             if (CONFIG_FLV_DECODER && s->h263_flv > 1) {
yading@10:                 ff_flv2_decode_ac_esc(&s->gb, &level, &run, &last);
yading@10:             } else {
yading@10:                 last = get_bits1(&s->gb);
yading@10:                 run = get_bits(&s->gb, 6);
yading@10:                 level = (int8_t)get_bits(&s->gb, 8);
yading@10:                 if(level == -128){
yading@10:                     if (s->codec_id == AV_CODEC_ID_RV10) {
yading@10:                         /* XXX: should patch encoder too */
yading@10:                         level = get_sbits(&s->gb, 12);
yading@10:                     }else{
yading@10:                         level = get_bits(&s->gb, 5);
yading@10:                         level |= get_sbits(&s->gb, 6)<<5;
yading@10:                     }
yading@10:                 }
yading@10:             }
yading@10:         } else {
yading@10:             run = rl->table_run[code];
yading@10:             level = rl->table_level[code];
yading@10:             last = code >= rl->last;
yading@10:             if (get_bits1(&s->gb))
yading@10:                 level = -level;
yading@10:         }
yading@10:         i += run;
yading@10:         if (i >= 64){
yading@10:             if(s->alt_inter_vlc && rl == &ff_h263_rl_inter && !s->mb_intra){
yading@10:                 //Looks like a hack but no, it's the way it is supposed to work ...
yading@10:                 rl = &ff_rl_intra_aic;
yading@10:                 i = 0;
yading@10:                 s->gb= gb;
yading@10:                 s->dsp.clear_block(block);
yading@10:                 goto retry;
yading@10:             }
yading@10:             av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d i:%d\n", s->mb_x, s->mb_y, s->mb_intra);
yading@10:             return -1;
yading@10:         }
yading@10:         j = scan_table[i];
yading@10:         block[j] = level;
yading@10:         if (last)
yading@10:             break;
yading@10:         i++;
yading@10:     }
yading@10: not_coded:
yading@10:     if (s->mb_intra && s->h263_aic) {
yading@10:         ff_h263_pred_acdc(s, block, n);
yading@10:         i = 63;
yading@10:     }
yading@10:     s->block_last_index[n] = i;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int h263_skip_b_part(MpegEncContext *s, int cbp)
yading@10: {
yading@10:     LOCAL_ALIGNED_16(int16_t, dblock, [64]);
yading@10:     int i, mbi;
yading@10:     int bli[6];
yading@10: 
yading@10:     /* we have to set s->mb_intra to zero to decode B-part of PB-frame correctly
yading@10:      * but real value should be restored in order to be used later (in OBMC condition)
yading@10:      */
yading@10:     mbi = s->mb_intra;
yading@10:     memcpy(bli, s->block_last_index, sizeof(bli));
yading@10:     s->mb_intra = 0;
yading@10:     for (i = 0; i < 6; i++) {
yading@10:         if (h263_decode_block(s, dblock, i, cbp&32) < 0)
yading@10:             return -1;
yading@10:         cbp+=cbp;
yading@10:     }
yading@10:     s->mb_intra = mbi;
yading@10:     memcpy(s->block_last_index, bli, sizeof(bli));
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int h263_get_modb(GetBitContext *gb, int pb_frame, int *cbpb)
yading@10: {
yading@10:     int c, mv = 1;
yading@10: 
yading@10:     if (pb_frame < 3) { // h.263 Annex G and i263 PB-frame
yading@10:         c = get_bits1(gb);
yading@10:         if (pb_frame == 2 && c)
yading@10:             mv = !get_bits1(gb);
yading@10:     } else { // h.263 Annex M improved PB-frame
yading@10:         mv = get_unary(gb, 0, 4) + 1;
yading@10:         c = mv & 1;
yading@10:         mv = !!(mv & 2);
yading@10:     }
yading@10:     if(c)
yading@10:         *cbpb = get_bits(gb, 6);
yading@10:     return mv;
yading@10: }
yading@10: 
yading@10: int ff_h263_decode_mb(MpegEncContext *s,
yading@10:                       int16_t block[6][64])
yading@10: {
yading@10:     int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
yading@10:     int16_t *mot_val;
yading@10:     const int xy= s->mb_x + s->mb_y * s->mb_stride;
yading@10:     int cbpb = 0, pb_mv_count = 0;
yading@10: 
yading@10:     av_assert2(!s->h263_pred);
yading@10: 
yading@10:     if (s->pict_type == AV_PICTURE_TYPE_P) {
yading@10:         do{
yading@10:             if (get_bits1(&s->gb)) {
yading@10:                 /* skip mb */
yading@10:                 s->mb_intra = 0;
yading@10:                 for(i=0;i<6;i++)
yading@10:                     s->block_last_index[i] = -1;
yading@10:                 s->mv_dir = MV_DIR_FORWARD;
yading@10:                 s->mv_type = MV_TYPE_16X16;
yading@10:                 s->current_picture.mb_type[xy] = MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0;
yading@10:                 s->mv[0][0][0] = 0;
yading@10:                 s->mv[0][0][1] = 0;
yading@10:                 s->mb_skipped = !(s->obmc | s->loop_filter);
yading@10:                 goto end;
yading@10:             }
yading@10:             cbpc = get_vlc2(&s->gb, ff_h263_inter_MCBPC_vlc.table, INTER_MCBPC_VLC_BITS, 2);
yading@10:             if (cbpc < 0){
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
yading@10:                 return -1;
yading@10:             }
yading@10:         }while(cbpc == 20);
yading@10: 
yading@10:         s->dsp.clear_blocks(s->block[0]);
yading@10: 
yading@10:         dquant = cbpc & 8;
yading@10:         s->mb_intra = ((cbpc & 4) != 0);
yading@10:         if (s->mb_intra) goto intra;
yading@10: 
yading@10:         if(s->pb_frame && get_bits1(&s->gb))
yading@10:             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
yading@10:         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
yading@10: 
yading@10:         if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
yading@10:             cbpy ^= 0xF;
yading@10: 
yading@10:         cbp = (cbpc & 3) | (cbpy << 2);
yading@10:         if (dquant) {
yading@10:             h263_decode_dquant(s);
yading@10:         }
yading@10: 
yading@10:         s->mv_dir = MV_DIR_FORWARD;
yading@10:         if ((cbpc & 16) == 0) {
yading@10:             s->current_picture.mb_type[xy] = MB_TYPE_16x16 | MB_TYPE_L0;
yading@10:             /* 16x16 motion prediction */
yading@10:             s->mv_type = MV_TYPE_16X16;
yading@10:             ff_h263_pred_motion(s, 0, 0, &pred_x, &pred_y);
yading@10:             if (s->umvplus)
yading@10:                mx = h263p_decode_umotion(s, pred_x);
yading@10:             else
yading@10:                mx = ff_h263_decode_motion(s, pred_x, 1);
yading@10: 
yading@10:             if (mx >= 0xffff)
yading@10:                 return -1;
yading@10: 
yading@10:             if (s->umvplus)
yading@10:                my = h263p_decode_umotion(s, pred_y);
yading@10:             else
yading@10:                my = ff_h263_decode_motion(s, pred_y, 1);
yading@10: 
yading@10:             if (my >= 0xffff)
yading@10:                 return -1;
yading@10:             s->mv[0][0][0] = mx;
yading@10:             s->mv[0][0][1] = my;
yading@10: 
yading@10:             if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
yading@10:                skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
yading@10:         } else {
yading@10:             s->current_picture.mb_type[xy] = MB_TYPE_8x8 | MB_TYPE_L0;
yading@10:             s->mv_type = MV_TYPE_8X8;
yading@10:             for(i=0;i<4;i++) {
yading@10:                 mot_val = ff_h263_pred_motion(s, i, 0, &pred_x, &pred_y);
yading@10:                 if (s->umvplus)
yading@10:                   mx = h263p_decode_umotion(s, pred_x);
yading@10:                 else
yading@10:                   mx = ff_h263_decode_motion(s, pred_x, 1);
yading@10:                 if (mx >= 0xffff)
yading@10:                     return -1;
yading@10: 
yading@10:                 if (s->umvplus)
yading@10:                   my = h263p_decode_umotion(s, pred_y);
yading@10:                 else
yading@10:                   my = ff_h263_decode_motion(s, pred_y, 1);
yading@10:                 if (my >= 0xffff)
yading@10:                     return -1;
yading@10:                 s->mv[0][i][0] = mx;
yading@10:                 s->mv[0][i][1] = my;
yading@10:                 if (s->umvplus && (mx - pred_x) == 1 && (my - pred_y) == 1)
yading@10:                   skip_bits1(&s->gb); /* Bit stuffing to prevent PSC */
yading@10:                 mot_val[0] = mx;
yading@10:                 mot_val[1] = my;
yading@10:             }
yading@10:         }
yading@10:     } else if(s->pict_type==AV_PICTURE_TYPE_B) {
yading@10:         int mb_type;
yading@10:         const int stride= s->b8_stride;
yading@10:         int16_t *mot_val0 = s->current_picture.motion_val[0][2 * (s->mb_x + s->mb_y * stride)];
yading@10:         int16_t *mot_val1 = s->current_picture.motion_val[1][2 * (s->mb_x + s->mb_y * stride)];
yading@10: //        const int mv_xy= s->mb_x + 1 + s->mb_y * s->mb_stride;
yading@10: 
yading@10:         //FIXME ugly
yading@10:         mot_val0[0       ]= mot_val0[2       ]= mot_val0[0+2*stride]= mot_val0[2+2*stride]=
yading@10:         mot_val0[1       ]= mot_val0[3       ]= mot_val0[1+2*stride]= mot_val0[3+2*stride]=
yading@10:         mot_val1[0       ]= mot_val1[2       ]= mot_val1[0+2*stride]= mot_val1[2+2*stride]=
yading@10:         mot_val1[1       ]= mot_val1[3       ]= mot_val1[1+2*stride]= mot_val1[3+2*stride]= 0;
yading@10: 
yading@10:         do{
yading@10:             mb_type= get_vlc2(&s->gb, h263_mbtype_b_vlc.table, H263_MBTYPE_B_VLC_BITS, 2);
yading@10:             if (mb_type < 0){
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "b mb_type damaged at %d %d\n", s->mb_x, s->mb_y);
yading@10:                 return -1;
yading@10:             }
yading@10: 
yading@10:             mb_type= h263_mb_type_b_map[ mb_type ];
yading@10:         }while(!mb_type);
yading@10: 
yading@10:         s->mb_intra = IS_INTRA(mb_type);
yading@10:         if(HAS_CBP(mb_type)){
yading@10:             s->dsp.clear_blocks(s->block[0]);
yading@10:             cbpc = get_vlc2(&s->gb, cbpc_b_vlc.table, CBPC_B_VLC_BITS, 1);
yading@10:             if(s->mb_intra){
yading@10:                 dquant = IS_QUANT(mb_type);
yading@10:                 goto intra;
yading@10:             }
yading@10: 
yading@10:             cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
yading@10: 
yading@10:             if (cbpy < 0){
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "b cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
yading@10:                 return -1;
yading@10:             }
yading@10: 
yading@10:             if(s->alt_inter_vlc==0 || (cbpc & 3)!=3)
yading@10:                 cbpy ^= 0xF;
yading@10: 
yading@10:             cbp = (cbpc & 3) | (cbpy << 2);
yading@10:         }else
yading@10:             cbp=0;
yading@10: 
yading@10:         av_assert2(!s->mb_intra);
yading@10: 
yading@10:         if(IS_QUANT(mb_type)){
yading@10:             h263_decode_dquant(s);
yading@10:         }
yading@10: 
yading@10:         if(IS_DIRECT(mb_type)){
yading@10:             s->mv_dir = MV_DIR_FORWARD | MV_DIR_BACKWARD | MV_DIRECT;
yading@10:             mb_type |= ff_mpeg4_set_direct_mv(s, 0, 0);
yading@10:         }else{
yading@10:             s->mv_dir = 0;
yading@10:             s->mv_type= MV_TYPE_16X16;
yading@10: //FIXME UMV
yading@10: 
yading@10:             if(USES_LIST(mb_type, 0)){
yading@10:                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 0, &mx, &my);
yading@10:                 s->mv_dir = MV_DIR_FORWARD;
yading@10: 
yading@10:                 mx = ff_h263_decode_motion(s, mx, 1);
yading@10:                 my = ff_h263_decode_motion(s, my, 1);
yading@10: 
yading@10:                 s->mv[0][0][0] = mx;
yading@10:                 s->mv[0][0][1] = my;
yading@10:                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
yading@10:                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
yading@10:             }
yading@10: 
yading@10:             if(USES_LIST(mb_type, 1)){
yading@10:                 int16_t *mot_val= ff_h263_pred_motion(s, 0, 1, &mx, &my);
yading@10:                 s->mv_dir |= MV_DIR_BACKWARD;
yading@10: 
yading@10:                 mx = ff_h263_decode_motion(s, mx, 1);
yading@10:                 my = ff_h263_decode_motion(s, my, 1);
yading@10: 
yading@10:                 s->mv[1][0][0] = mx;
yading@10:                 s->mv[1][0][1] = my;
yading@10:                 mot_val[0       ]= mot_val[2       ]= mot_val[0+2*stride]= mot_val[2+2*stride]= mx;
yading@10:                 mot_val[1       ]= mot_val[3       ]= mot_val[1+2*stride]= mot_val[3+2*stride]= my;
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         s->current_picture.mb_type[xy] = mb_type;
yading@10:     } else { /* I-Frame */
yading@10:         do{
yading@10:             cbpc = get_vlc2(&s->gb, ff_h263_intra_MCBPC_vlc.table, INTRA_MCBPC_VLC_BITS, 2);
yading@10:             if (cbpc < 0){
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "I cbpc damaged at %d %d\n", s->mb_x, s->mb_y);
yading@10:                 return -1;
yading@10:             }
yading@10:         }while(cbpc == 8);
yading@10: 
yading@10:         s->dsp.clear_blocks(s->block[0]);
yading@10: 
yading@10:         dquant = cbpc & 4;
yading@10:         s->mb_intra = 1;
yading@10: intra:
yading@10:         s->current_picture.mb_type[xy] = MB_TYPE_INTRA;
yading@10:         if (s->h263_aic) {
yading@10:             s->ac_pred = get_bits1(&s->gb);
yading@10:             if(s->ac_pred){
yading@10:                 s->current_picture.mb_type[xy] = MB_TYPE_INTRA | MB_TYPE_ACPRED;
yading@10: 
yading@10:                 s->h263_aic_dir = get_bits1(&s->gb);
yading@10:             }
yading@10:         }else
yading@10:             s->ac_pred = 0;
yading@10: 
yading@10:         if(s->pb_frame && get_bits1(&s->gb))
yading@10:             pb_mv_count = h263_get_modb(&s->gb, s->pb_frame, &cbpb);
yading@10:         cbpy = get_vlc2(&s->gb, ff_h263_cbpy_vlc.table, CBPY_VLC_BITS, 1);
yading@10:         if(cbpy<0){
yading@10:             av_log(s->avctx, AV_LOG_ERROR, "I cbpy damaged at %d %d\n", s->mb_x, s->mb_y);
yading@10:             return -1;
yading@10:         }
yading@10:         cbp = (cbpc & 3) | (cbpy << 2);
yading@10:         if (dquant) {
yading@10:             h263_decode_dquant(s);
yading@10:         }
yading@10: 
yading@10:         pb_mv_count += !!s->pb_frame;
yading@10:     }
yading@10: 
yading@10:     while(pb_mv_count--){
yading@10:         ff_h263_decode_motion(s, 0, 1);
yading@10:         ff_h263_decode_motion(s, 0, 1);
yading@10:     }
yading@10: 
yading@10:     /* decode each block */
yading@10:     for (i = 0; i < 6; i++) {
yading@10:         if (h263_decode_block(s, block[i], i, cbp&32) < 0)
yading@10:             return -1;
yading@10:         cbp+=cbp;
yading@10:     }
yading@10: 
yading@10:     if(s->pb_frame && h263_skip_b_part(s, cbpb) < 0)
yading@10:         return -1;
yading@10:     if(s->obmc && !s->mb_intra){
yading@10:         if(s->pict_type == AV_PICTURE_TYPE_P && s->mb_x+1<s->mb_width && s->mb_num_left != 1)
yading@10:             preview_obmc(s);
yading@10:     }
yading@10: end:
yading@10: 
yading@10:         /* per-MB end of slice check */
yading@10:     {
yading@10:         int v= show_bits(&s->gb, 16);
yading@10: 
yading@10:         if (get_bits_left(&s->gb) < 16) {
yading@10:             v >>= 16 - get_bits_left(&s->gb);
yading@10:         }
yading@10: 
yading@10:         if(v==0)
yading@10:             return SLICE_END;
yading@10:     }
yading@10: 
yading@10:     return SLICE_OK;
yading@10: }
yading@10: 
yading@10: /* most is hardcoded. should extend to handle all h263 streams */
yading@10: int ff_h263_decode_picture_header(MpegEncContext *s)
yading@10: {
yading@10:     int format, width, height, i;
yading@10:     uint32_t startcode;
yading@10: 
yading@10:     align_get_bits(&s->gb);
yading@10: 
yading@10:     startcode= get_bits(&s->gb, 22-8);
yading@10: 
yading@10:     for(i= get_bits_left(&s->gb); i>24; i-=8) {
yading@10:         startcode = ((startcode << 8) | get_bits(&s->gb, 8)) & 0x003FFFFF;
yading@10: 
yading@10:         if(startcode == 0x20)
yading@10:             break;
yading@10:     }
yading@10: 
yading@10:     if (startcode != 0x20) {
yading@10:         av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n");
yading@10:         return -1;
yading@10:     }
yading@10:     /* temporal reference */
yading@10:     i = get_bits(&s->gb, 8); /* picture timestamp */
yading@10:     if( (s->picture_number&~0xFF)+i < s->picture_number)
yading@10:         i+= 256;
yading@10:     s->current_picture_ptr->f.pts =
yading@10:     s->picture_number= (s->picture_number&~0xFF) + i;
yading@10: 
yading@10:     /* PTYPE starts here */
yading@10:     if (get_bits1(&s->gb) != 1) {
yading@10:         /* marker */
yading@10:         av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n");
yading@10:         return -1;
yading@10:     }
yading@10:     if (get_bits1(&s->gb) != 0) {
yading@10:         av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n");
yading@10:         return -1;      /* h263 id */
yading@10:     }
yading@10:     skip_bits1(&s->gb);         /* split screen off */
yading@10:     skip_bits1(&s->gb);         /* camera  off */
yading@10:     skip_bits1(&s->gb);         /* freeze picture release off */
yading@10: 
yading@10:     format = get_bits(&s->gb, 3);
yading@10:     /*
yading@10:         0    forbidden
yading@10:         1    sub-QCIF
yading@10:         10   QCIF
yading@10:         7       extended PTYPE (PLUSPTYPE)
yading@10:     */
yading@10: 
yading@10:     if (format != 7 && format != 6) {
yading@10:         s->h263_plus = 0;
yading@10:         /* H.263v1 */
yading@10:         width = ff_h263_format[format][0];
yading@10:         height = ff_h263_format[format][1];
yading@10:         if (!width)
yading@10:             return -1;
yading@10: 
yading@10:         s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb);
yading@10: 
yading@10:         s->h263_long_vectors = get_bits1(&s->gb);
yading@10: 
yading@10:         if (get_bits1(&s->gb) != 0) {
yading@10:             av_log(s->avctx, AV_LOG_ERROR, "H263 SAC not supported\n");
yading@10:             return -1; /* SAC: off */
yading@10:         }
yading@10:         s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
yading@10:         s->unrestricted_mv = s->h263_long_vectors || s->obmc;
yading@10: 
yading@10:         s->pb_frame = get_bits1(&s->gb);
yading@10:         s->chroma_qscale= s->qscale = get_bits(&s->gb, 5);
yading@10:         skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */
yading@10: 
yading@10:         s->width = width;
yading@10:         s->height = height;
yading@10:         s->avctx->sample_aspect_ratio= (AVRational){12,11};
yading@10:         s->avctx->time_base= (AVRational){1001, 30000};
yading@10:     } else {
yading@10:         int ufep;
yading@10: 
yading@10:         /* H.263v2 */
yading@10:         s->h263_plus = 1;
yading@10:         ufep = get_bits(&s->gb, 3); /* Update Full Extended PTYPE */
yading@10: 
yading@10:         /* ufep other than 0 and 1 are reserved */
yading@10:         if (ufep == 1) {
yading@10:             /* OPPTYPE */
yading@10:             format = get_bits(&s->gb, 3);
yading@10:             av_dlog(s->avctx, "ufep=1, format: %d\n", format);
yading@10:             s->custom_pcf= get_bits1(&s->gb);
yading@10:             s->umvplus = get_bits1(&s->gb); /* Unrestricted Motion Vector */
yading@10:             if (get_bits1(&s->gb) != 0) {
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "Syntax-based Arithmetic Coding (SAC) not supported\n");
yading@10:             }
yading@10:             s->obmc= get_bits1(&s->gb); /* Advanced prediction mode */
yading@10:             s->h263_aic = get_bits1(&s->gb); /* Advanced Intra Coding (AIC) */
yading@10:             s->loop_filter= get_bits1(&s->gb);
yading@10:             s->unrestricted_mv = s->umvplus || s->obmc || s->loop_filter;
yading@10:             if(s->avctx->lowres)
yading@10:                 s->loop_filter = 0;
yading@10: 
yading@10:             s->h263_slice_structured= get_bits1(&s->gb);
yading@10:             if (get_bits1(&s->gb) != 0) {
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "Reference Picture Selection not supported\n");
yading@10:             }
yading@10:             if (get_bits1(&s->gb) != 0) {
yading@10:                 av_log(s->avctx, AV_LOG_ERROR, "Independent Segment Decoding not supported\n");
yading@10:             }
yading@10:             s->alt_inter_vlc= get_bits1(&s->gb);
yading@10:             s->modified_quant= get_bits1(&s->gb);
yading@10:             if(s->modified_quant)
yading@10:                 s->chroma_qscale_table= ff_h263_chroma_qscale_table;
yading@10: 
yading@10:             skip_bits(&s->gb, 1); /* Prevent start code emulation */
yading@10: 
yading@10:             skip_bits(&s->gb, 3); /* Reserved */
yading@10:         } else if (ufep != 0) {
yading@10:             av_log(s->avctx, AV_LOG_ERROR, "Bad UFEP type (%d)\n", ufep);
yading@10:             return -1;
yading@10:         }
yading@10: 
yading@10:         /* MPPTYPE */
yading@10:         s->pict_type = get_bits(&s->gb, 3);
yading@10:         switch(s->pict_type){
yading@10:         case 0: s->pict_type= AV_PICTURE_TYPE_I;break;
yading@10:         case 1: s->pict_type= AV_PICTURE_TYPE_P;break;
yading@10:         case 2: s->pict_type= AV_PICTURE_TYPE_P;s->pb_frame = 3;break;
yading@10:         case 3: s->pict_type= AV_PICTURE_TYPE_B;break;
yading@10:         case 7: s->pict_type= AV_PICTURE_TYPE_I;break; //ZYGO
yading@10:         default:
yading@10:             return -1;
yading@10:         }
yading@10:         skip_bits(&s->gb, 2);
yading@10:         s->no_rounding = get_bits1(&s->gb);
yading@10:         skip_bits(&s->gb, 4);
yading@10: 
yading@10:         /* Get the picture dimensions */
yading@10:         if (ufep) {
yading@10:             if (format == 6) {
yading@10:                 /* Custom Picture Format (CPFMT) */
yading@10:                 s->aspect_ratio_info = get_bits(&s->gb, 4);
yading@10:                 av_dlog(s->avctx, "aspect: %d\n", s->aspect_ratio_info);
yading@10:                 /* aspect ratios:
yading@10:                 0 - forbidden
yading@10:                 1 - 1:1
yading@10:                 2 - 12:11 (CIF 4:3)
yading@10:                 3 - 10:11 (525-type 4:3)
yading@10:                 4 - 16:11 (CIF 16:9)
yading@10:                 5 - 40:33 (525-type 16:9)
yading@10:                 6-14 - reserved
yading@10:                 */
yading@10:                 width = (get_bits(&s->gb, 9) + 1) * 4;
yading@10:                 skip_bits1(&s->gb);
yading@10:                 height = get_bits(&s->gb, 9) * 4;
yading@10:                 av_dlog(s->avctx, "\nH.263+ Custom picture: %dx%d\n",width,height);
yading@10:                 if (s->aspect_ratio_info == FF_ASPECT_EXTENDED) {
yading@10:                     /* aspected dimensions */
yading@10:                     s->avctx->sample_aspect_ratio.num= get_bits(&s->gb, 8);
yading@10:                     s->avctx->sample_aspect_ratio.den= get_bits(&s->gb, 8);
yading@10:                 }else{
yading@10:                     s->avctx->sample_aspect_ratio= ff_h263_pixel_aspect[s->aspect_ratio_info];
yading@10:                 }
yading@10:             } else {
yading@10:                 width = ff_h263_format[format][0];
yading@10:                 height = ff_h263_format[format][1];
yading@10:                 s->avctx->sample_aspect_ratio= (AVRational){12,11};
yading@10:             }
yading@10:             if ((width == 0) || (height == 0))
yading@10:                 return -1;
yading@10:             s->width = width;
yading@10:             s->height = height;
yading@10: 
yading@10:             if(s->custom_pcf){
yading@10:                 int gcd;
yading@10:                 s->avctx->time_base.den= 1800000;
yading@10:                 s->avctx->time_base.num= 1000 + get_bits1(&s->gb);
yading@10:                 s->avctx->time_base.num*= get_bits(&s->gb, 7);
yading@10:                 if(s->avctx->time_base.num == 0){
yading@10:                     av_log(s, AV_LOG_ERROR, "zero framerate\n");
yading@10:                     return -1;
yading@10:                 }
yading@10:                 gcd= av_gcd(s->avctx->time_base.den, s->avctx->time_base.num);
yading@10:                 s->avctx->time_base.den /= gcd;
yading@10:                 s->avctx->time_base.num /= gcd;
yading@10:             }else{
yading@10:                 s->avctx->time_base= (AVRational){1001, 30000};
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         if(s->custom_pcf){
yading@10:             skip_bits(&s->gb, 2); //extended Temporal reference
yading@10:         }
yading@10: 
yading@10:         if (ufep) {
yading@10:             if (s->umvplus) {
yading@10:                 if(get_bits1(&s->gb)==0) /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
yading@10:                     skip_bits1(&s->gb);
yading@10:             }
yading@10:             if(s->h263_slice_structured){
yading@10:                 if (get_bits1(&s->gb) != 0) {
yading@10:                     av_log(s->avctx, AV_LOG_ERROR, "rectangular slices not supported\n");
yading@10:                 }
yading@10:                 if (get_bits1(&s->gb) != 0) {
yading@10:                     av_log(s->avctx, AV_LOG_ERROR, "unordered slices not supported\n");
yading@10:                 }
yading@10:             }
yading@10:         }
yading@10: 
yading@10:         s->qscale = get_bits(&s->gb, 5);
yading@10:     }
yading@10: 
yading@10:     if (s->width == 0 || s->height == 0) {
yading@10:         av_log(s->avctx, AV_LOG_ERROR, "dimensions 0\n");
yading@10:         return -1;
yading@10:     }
yading@10:     s->mb_width = (s->width  + 15) / 16;
yading@10:     s->mb_height = (s->height  + 15) / 16;
yading@10:     s->mb_num = s->mb_width * s->mb_height;
yading@10: 
yading@10:     if (s->pb_frame) {
yading@10:         skip_bits(&s->gb, 3); /* Temporal reference for B-pictures */
yading@10:         if (s->custom_pcf)
yading@10:             skip_bits(&s->gb, 2); //extended Temporal reference
yading@10:         skip_bits(&s->gb, 2); /* Quantization information for B-pictures */
yading@10:     }
yading@10: 
yading@10:     if (s->pict_type!=AV_PICTURE_TYPE_B) {
yading@10:         s->time            = s->picture_number;
yading@10:         s->pp_time         = s->time - s->last_non_b_time;
yading@10:         s->last_non_b_time = s->time;
yading@10:     }else{
yading@10:         s->time    = s->picture_number;
yading@10:         s->pb_time = s->pp_time - (s->last_non_b_time - s->time);
yading@10:         if (s->pp_time <=s->pb_time ||
yading@10:             s->pp_time <= s->pp_time - s->pb_time ||
yading@10:             s->pp_time <= 0){
yading@10:             s->pp_time = 2;
yading@10:             s->pb_time = 1;
yading@10:         }
yading@10:         ff_mpeg4_init_direct_mv(s);
yading@10:     }
yading@10: 
yading@10:     /* PEI */
yading@10:     while (get_bits1(&s->gb) != 0) {
yading@10:         skip_bits(&s->gb, 8);
yading@10:     }
yading@10: 
yading@10:     if(s->h263_slice_structured){
yading@10:         if (get_bits1(&s->gb) != 1) {
yading@10:             av_log(s->avctx, AV_LOG_ERROR, "SEPB1 marker missing\n");
yading@10:             return -1;
yading@10:         }
yading@10: 
yading@10:         ff_h263_decode_mba(s);
yading@10: 
yading@10:         if (get_bits1(&s->gb) != 1) {
yading@10:             av_log(s->avctx, AV_LOG_ERROR, "SEPB2 marker missing\n");
yading@10:             return -1;
yading@10:         }
yading@10:     }
yading@10:     s->f_code = 1;
yading@10: 
yading@10:     if(s->h263_aic){
yading@10:          s->y_dc_scale_table=
yading@10:          s->c_dc_scale_table= ff_aic_dc_scale_table;
yading@10:     }else{
yading@10:         s->y_dc_scale_table=
yading@10:         s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
yading@10:     }
yading@10: 
yading@10:         ff_h263_show_pict_info(s);
yading@10:     if (s->pict_type == AV_PICTURE_TYPE_I && s->codec_tag == AV_RL32("ZYGO") && get_bits_left(&s->gb) >= 85 + 13*3*16 + 50){
yading@10:         int i,j;
yading@10:         for(i=0; i<85; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
yading@10:         av_log(s->avctx, AV_LOG_DEBUG, "\n");
yading@10:         for(i=0; i<13; i++){
yading@10:             for(j=0; j<3; j++){
yading@10:                 int v= get_bits(&s->gb, 8);
yading@10:                 v |= get_sbits(&s->gb, 8)<<8;
yading@10:                 av_log(s->avctx, AV_LOG_DEBUG, " %5d", v);
yading@10:             }
yading@10:             av_log(s->avctx, AV_LOG_DEBUG, "\n");
yading@10:         }
yading@10:         for(i=0; i<50; i++) av_log(s->avctx, AV_LOG_DEBUG, "%d", get_bits1(&s->gb));
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }