Split motion vector prediction off h264.c/h.

Originally committed as revision 21174 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 237 insertions, 0 deletions

diff --git a/libavcodec/h264_mvpred.h b/libavcodec/h264_mvpred.h
new file mode 100644
index 0000000000..f6c503a976
--- /dev/null
+++ b/libavcodec/h264_mvpred.h
@@ -0,0 +1,237 @@
+/*
+ * H.26L/H.264/AVC/JVT/14496-10/... motion vector predicion
+ * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file libavcodec/h264_mvpred.h
+ * H.264 / AVC / MPEG4 part10 motion vector predicion.
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+#include "internal.h"
+#include "avcodec.h"
+#include "h264.h"
+
+//#undef NDEBUG
+#include <assert.h>
+
+static inline int fetch_diagonal_mv(H264Context *h, const int16_t **C, int i, int list, int part_width){
+    const int topright_ref= h->ref_cache[list][ i - 8 + part_width ];
+    MpegEncContext *s = &h->s;
+
+    /* there is no consistent mapping of mvs to neighboring locations that will
+     * make mbaff happy, so we can't move all this logic to fill_caches */
+    if(FRAME_MBAFF){
+        const uint32_t *mb_types = s->current_picture_ptr->mb_type;
+        const int16_t *mv;
+        *(uint32_t*)h->mv_cache[list][scan8[0]-2] = 0;
+        *C = h->mv_cache[list][scan8[0]-2];
+
+        if(!MB_FIELD
+           && (s->mb_y&1) && i < scan8[0]+8 && topright_ref != PART_NOT_AVAILABLE){
+            int topright_xy = s->mb_x + (s->mb_y-1)*s->mb_stride + (i == scan8[0]+3);
+            if(IS_INTERLACED(mb_types[topright_xy])){
+#define SET_DIAG_MV(MV_OP, REF_OP, X4, Y4)\
+                const int x4 = X4, y4 = Y4;\
+                const int mb_type = mb_types[(x4>>2)+(y4>>2)*s->mb_stride];\
+                if(!USES_LIST(mb_type,list))\
+                    return LIST_NOT_USED;\
+                mv = s->current_picture_ptr->motion_val[list][x4 + y4*h->b_stride];\
+                h->mv_cache[list][scan8[0]-2][0] = mv[0];\
+                h->mv_cache[list][scan8[0]-2][1] = mv[1] MV_OP;\
+                return s->current_picture_ptr->ref_index[list][(x4>>1) + (y4>>1)*h->b8_stride] REF_OP;
+
+                SET_DIAG_MV(*2, >>1, s->mb_x*4+(i&7)-4+part_width, s->mb_y*4-1);
+            }
+        }
+        if(topright_ref == PART_NOT_AVAILABLE
+           && ((s->mb_y&1) || i >= scan8[0]+8) && (i&7)==4
+           && h->ref_cache[list][scan8[0]-1] != PART_NOT_AVAILABLE){
+            if(!MB_FIELD
+               && IS_INTERLACED(mb_types[h->left_mb_xy[0]])){
+                SET_DIAG_MV(*2, >>1, s->mb_x*4-1, (s->mb_y|1)*4+(s->mb_y&1)*2+(i>>4)-1);
+            }
+            if(MB_FIELD
+               && !IS_INTERLACED(mb_types[h->left_mb_xy[0]])
+               && i >= scan8[0]+8){
+                // left shift will turn LIST_NOT_USED into PART_NOT_AVAILABLE, but that's OK.
+                SET_DIAG_MV(/2, <<1, s->mb_x*4-1, (s->mb_y&~1)*4 - 1 + ((i-scan8[0])>>3)*2);
+            }
+        }
+#undef SET_DIAG_MV
+    }
+
+    if(topright_ref != PART_NOT_AVAILABLE){
+        *C= h->mv_cache[list][ i - 8 + part_width ];
+        return topright_ref;
+    }else{
+        tprintf(s->avctx, "topright MV not available\n");
+
+        *C= h->mv_cache[list][ i - 8 - 1 ];
+        return h->ref_cache[list][ i - 8 - 1 ];
+    }
+}
+
+/**
+ * gets the predicted MV.
+ * @param n the block index
+ * @param part_width the width of the partition (4, 8,16) -> (1, 2, 4)
+ * @param mx the x component of the predicted motion vector
+ * @param my the y component of the predicted motion vector
+ */
+static inline void pred_motion(H264Context * const h, int n, int part_width, int list, int ref, int * const mx, int * const my){
+    const int index8= scan8[n];
+    const int top_ref=      h->ref_cache[list][ index8 - 8 ];
+    const int left_ref=     h->ref_cache[list][ index8 - 1 ];
+    const int16_t * const A= h->mv_cache[list][ index8 - 1 ];
+    const int16_t * const B= h->mv_cache[list][ index8 - 8 ];
+    const int16_t * C;
+    int diagonal_ref, match_count;
+
+    assert(part_width==1 || part_width==2 || part_width==4);
+
+/* mv_cache
+  B . . A T T T T
+  U . . L . . , .
+  U . . L . . . .
+  U . . L . . , .
+  . . . L . . . .
+*/
+
+    diagonal_ref= fetch_diagonal_mv(h, &C, index8, list, part_width);
+    match_count= (diagonal_ref==ref) + (top_ref==ref) + (left_ref==ref);
+    tprintf(h->s.avctx, "pred_motion match_count=%d\n", match_count);
+    if(match_count > 1){ //most common
+        *mx= mid_pred(A[0], B[0], C[0]);
+        *my= mid_pred(A[1], B[1], C[1]);
+    }else if(match_count==1){
+        if(left_ref==ref){
+            *mx= A[0];
+            *my= A[1];
+        }else if(top_ref==ref){
+            *mx= B[0];
+            *my= B[1];
+        }else{
+            *mx= C[0];
+            *my= C[1];
+        }
+    }else{
+        if(top_ref == PART_NOT_AVAILABLE && diagonal_ref == PART_NOT_AVAILABLE && left_ref != PART_NOT_AVAILABLE){
+            *mx= A[0];
+            *my= A[1];
+        }else{
+            *mx= mid_pred(A[0], B[0], C[0]);
+            *my= mid_pred(A[1], B[1], C[1]);
+        }
+    }
+
+    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);
+}
+
+/**
+ * gets the directionally predicted 16x8 MV.
+ * @param n the block index
+ * @param mx the x component of the predicted motion vector
+ * @param my the y component of the predicted motion vector
+ */
+static inline void pred_16x8_motion(H264Context * const h, int n, int list, int ref, int * const mx, int * const my){
+    if(n==0){
+        const int top_ref=      h->ref_cache[list][ scan8[0] - 8 ];
+        const int16_t * const B= h->mv_cache[list][ scan8[0] - 8 ];
+
+        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);
+
+        if(top_ref == ref){
+            *mx= B[0];
+            *my= B[1];
+            return;
+        }
+    }else{
+        const int left_ref=     h->ref_cache[list][ scan8[8] - 1 ];
+        const int16_t * const A= h->mv_cache[list][ scan8[8] - 1 ];
+
+        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);
+
+        if(left_ref == ref){
+            *mx= A[0];
+            *my= A[1];
+            return;
+        }
+    }
+
+    //RARE
+    pred_motion(h, n, 4, list, ref, mx, my);
+}
+
+/**
+ * gets the directionally predicted 8x16 MV.
+ * @param n the block index
+ * @param mx the x component of the predicted motion vector
+ * @param my the y component of the predicted motion vector
+ */
+static inline void pred_8x16_motion(H264Context * const h, int n, int list, int ref, int * const mx, int * const my){
+    if(n==0){
+        const int left_ref=      h->ref_cache[list][ scan8[0] - 1 ];
+        const int16_t * const A=  h->mv_cache[list][ scan8[0] - 1 ];
+
+        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);
+
+        if(left_ref == ref){
+            *mx= A[0];
+            *my= A[1];
+            return;
+        }
+    }else{
+        const int16_t * C;
+        int diagonal_ref;
+
+        diagonal_ref= fetch_diagonal_mv(h, &C, scan8[4], list, 2);
+
+        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);
+
+        if(diagonal_ref == ref){
+            *mx= C[0];
+            *my= C[1];
+            return;
+        }
+    }
+
+    //RARE
+    pred_motion(h, n, 2, list, ref, mx, my);
+}
+
+static inline void pred_pskip_motion(H264Context * const h, int * const mx, int * const my){
+    const int top_ref = h->ref_cache[0][ scan8[0] - 8 ];
+    const int left_ref= h->ref_cache[0][ scan8[0] - 1 ];
+
+    tprintf(h->s.avctx, "pred_pskip: (%d) (%d) at %2d %2d\n", top_ref, left_ref, h->s.mb_x, h->s.mb_y);
+
+    if(top_ref == PART_NOT_AVAILABLE || left_ref == PART_NOT_AVAILABLE
+       || !( top_ref | *(uint32_t*)h->mv_cache[0][ scan8[0] - 8 ])
+       || !(left_ref | *(uint32_t*)h->mv_cache[0][ scan8[0] - 1 ])){
+
+        *mx = *my = 0;
+        return;
+    }
+
+    pred_motion(h, 0, 4, 0, 0, mx, my);
+
+    return;
+}