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libavcodec/h264_mvpred.h

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00001 /*
00002  * H.26L/H.264/AVC/JVT/14496-10/... motion vector predicion
00003  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00028 #ifndef AVCODEC_H264_MVPRED_H
00029 #define AVCODEC_H264_MVPRED_H
00030 
00031 #include "internal.h"
00032 #include "avcodec.h"
00033 #include "h264.h"
00034 
00035 //#undef NDEBUG
00036 #include <assert.h>
00037 
00038 static inline int fetch_diagonal_mv(H264Context *h, const int16_t **C, int i, int list, int part_width){
00039     const int topright_ref= h->ref_cache[list][ i - 8 + part_width ];
00040     MpegEncContext *s = &h->s;
00041 
00042     /* there is no consistent mapping of mvs to neighboring locations that will
00043      * make mbaff happy, so we can't move all this logic to fill_caches */
00044     if(FRAME_MBAFF){
00045 
00046 #define SET_DIAG_MV(MV_OP, REF_OP, XY, Y4)\
00047                 const int xy = XY, y4 = Y4;\
00048                 const int mb_type = mb_types[xy+(y4>>2)*s->mb_stride];\
00049                 if(!USES_LIST(mb_type,list))\
00050                     return LIST_NOT_USED;\
00051                 mv = s->current_picture_ptr->motion_val[list][h->mb2b_xy[xy]+3 + y4*h->b_stride];\
00052                 h->mv_cache[list][scan8[0]-2][0] = mv[0];\
00053                 h->mv_cache[list][scan8[0]-2][1] = mv[1] MV_OP;\
00054                 return s->current_picture_ptr->ref_index[list][4*xy+1 + (y4&~1)] REF_OP;
00055 
00056         if(topright_ref == PART_NOT_AVAILABLE
00057            && i >= scan8[0]+8 && (i&7)==4
00058            && h->ref_cache[list][scan8[0]-1] != PART_NOT_AVAILABLE){
00059             const uint32_t *mb_types = s->current_picture_ptr->mb_type;
00060             const int16_t *mv;
00061             AV_ZERO32(h->mv_cache[list][scan8[0]-2]);
00062             *C = h->mv_cache[list][scan8[0]-2];
00063 
00064             if(!MB_FIELD
00065                && IS_INTERLACED(h->left_type[0])){
00066                 SET_DIAG_MV(*2, >>1, h->left_mb_xy[0]+s->mb_stride, (s->mb_y&1)*2+(i>>5));
00067                 assert(h->left_mb_xy[0] == h->left_mb_xy[1]);
00068             }
00069             if(MB_FIELD
00070                && !IS_INTERLACED(h->left_type[0])){
00071                 // left shift will turn LIST_NOT_USED into PART_NOT_AVAILABLE, but that's OK.
00072                 SET_DIAG_MV(/2, <<1, h->left_mb_xy[i>=36], ((i>>2))&3);
00073             }
00074         }
00075 #undef SET_DIAG_MV
00076     }
00077 
00078     if(topright_ref != PART_NOT_AVAILABLE){
00079         *C= h->mv_cache[list][ i - 8 + part_width ];
00080         return topright_ref;
00081     }else{
00082         tprintf(s->avctx, "topright MV not available\n");
00083 
00084         *C= h->mv_cache[list][ i - 8 - 1 ];
00085         return h->ref_cache[list][ i - 8 - 1 ];
00086     }
00087 }
00088 
00096 static inline void pred_motion(H264Context * const h, int n, int part_width, int list, int ref, int * const mx, int * const my){
00097     const int index8= scan8[n];
00098     const int top_ref=      h->ref_cache[list][ index8 - 8 ];
00099     const int left_ref=     h->ref_cache[list][ index8 - 1 ];
00100     const int16_t * const A= h->mv_cache[list][ index8 - 1 ];
00101     const int16_t * const B= h->mv_cache[list][ index8 - 8 ];
00102     const int16_t * C;
00103     int diagonal_ref, match_count;
00104 
00105     assert(part_width==1 || part_width==2 || part_width==4);
00106 
00107 /* mv_cache
00108   B . . A T T T T
00109   U . . L . . , .
00110   U . . L . . . .
00111   U . . L . . , .
00112   . . . L . . . .
00113 */
00114 
00115     diagonal_ref= fetch_diagonal_mv(h, &C, index8, list, part_width);
00116     match_count= (diagonal_ref==ref) + (top_ref==ref) + (left_ref==ref);
00117     tprintf(h->s.avctx, "pred_motion match_count=%d\n", match_count);
00118     if(match_count > 1){ //most common
00119         *mx= mid_pred(A[0], B[0], C[0]);
00120         *my= mid_pred(A[1], B[1], C[1]);
00121     }else if(match_count==1){
00122         if(left_ref==ref){
00123             *mx= A[0];
00124             *my= A[1];
00125         }else if(top_ref==ref){
00126             *mx= B[0];
00127             *my= B[1];
00128         }else{
00129             *mx= C[0];
00130             *my= C[1];
00131         }
00132     }else{
00133         if(top_ref == PART_NOT_AVAILABLE && diagonal_ref == PART_NOT_AVAILABLE && left_ref != PART_NOT_AVAILABLE){
00134             *mx= A[0];
00135             *my= A[1];
00136         }else{
00137             *mx= mid_pred(A[0], B[0], C[0]);
00138             *my= mid_pred(A[1], B[1], C[1]);
00139         }
00140     }
00141 
00142     tprintf(h->s.avctx, "pred_motion (%2d %2d %2d) (%2d %2d %2d) (%2d %2d %2d) -> (%2d %2d %2d) at %2d %2d %d list %d\n", top_ref, B[0], B[1],                    diagonal_ref, C[0], C[1], left_ref, A[0], A[1], ref, *mx, *my, h->s.mb_x, h->s.mb_y, n, list);
00143 }
00144 
00151 static inline void pred_16x8_motion(H264Context * const h, int n, int list, int ref, int * const mx, int * const my){
00152     if(n==0){
00153         const int top_ref=      h->ref_cache[list][ scan8[0] - 8 ];
00154         const int16_t * const B= h->mv_cache[list][ scan8[0] - 8 ];
00155 
00156         tprintf(h->s.avctx, "pred_16x8: (%2d %2d %2d) at %2d %2d %d list %d\n", top_ref, B[0], B[1], h->s.mb_x, h->s.mb_y, n, list);
00157 
00158         if(top_ref == ref){
00159             *mx= B[0];
00160             *my= B[1];
00161             return;
00162         }
00163     }else{
00164         const int left_ref=     h->ref_cache[list][ scan8[8] - 1 ];
00165         const int16_t * const A= h->mv_cache[list][ scan8[8] - 1 ];
00166 
00167         tprintf(h->s.avctx, "pred_16x8: (%2d %2d %2d) at %2d %2d %d list %d\n", left_ref, A[0], A[1], h->s.mb_x, h->s.mb_y, n, list);
00168 
00169         if(left_ref == ref){
00170             *mx= A[0];
00171             *my= A[1];
00172             return;
00173         }
00174     }
00175 
00176     //RARE
00177     pred_motion(h, n, 4, list, ref, mx, my);
00178 }
00179 
00186 static inline void pred_8x16_motion(H264Context * const h, int n, int list, int ref, int * const mx, int * const my){
00187     if(n==0){
00188         const int left_ref=      h->ref_cache[list][ scan8[0] - 1 ];
00189         const int16_t * const A=  h->mv_cache[list][ scan8[0] - 1 ];
00190 
00191         tprintf(h->s.avctx, "pred_8x16: (%2d %2d %2d) at %2d %2d %d list %d\n", left_ref, A[0], A[1], h->s.mb_x, h->s.mb_y, n, list);
00192 
00193         if(left_ref == ref){
00194             *mx= A[0];
00195             *my= A[1];
00196             return;
00197         }
00198     }else{
00199         const int16_t * C;
00200         int diagonal_ref;
00201 
00202         diagonal_ref= fetch_diagonal_mv(h, &C, scan8[4], list, 2);
00203 
00204         tprintf(h->s.avctx, "pred_8x16: (%2d %2d %2d) at %2d %2d %d list %d\n", diagonal_ref, C[0], C[1], h->s.mb_x, h->s.mb_y, n, list);
00205 
00206         if(diagonal_ref == ref){
00207             *mx= C[0];
00208             *my= C[1];
00209             return;
00210         }
00211     }
00212 
00213     //RARE
00214     pred_motion(h, n, 2, list, ref, mx, my);
00215 }
00216 
00217 static inline void pred_pskip_motion(H264Context * const h, int * const mx, int * const my){
00218     const int top_ref = h->ref_cache[0][ scan8[0] - 8 ];
00219     const int left_ref= h->ref_cache[0][ scan8[0] - 1 ];
00220 
00221     tprintf(h->s.avctx, "pred_pskip: (%d) (%d) at %2d %2d\n", top_ref, left_ref, h->s.mb_x, h->s.mb_y);
00222 
00223     if(top_ref == PART_NOT_AVAILABLE || left_ref == PART_NOT_AVAILABLE
00224        || !( top_ref | AV_RN32A(h->mv_cache[0][ scan8[0] - 8 ]))
00225        || !(left_ref | AV_RN32A(h->mv_cache[0][ scan8[0] - 1 ]))){
00226 
00227         *mx = *my = 0;
00228         return;
00229     }
00230 
00231     pred_motion(h, 0, 4, 0, 0, mx, my);
00232 
00233     return;
00234 }
00235 
00236 #endif /* AVCODEC_H264_MVPRED_H */

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