diff --git a/libavcodec/h264.c b/libavcodec/h264.c
index a68a911cd4..a53be146e7 100644
--- a/libavcodec/h264.c
+++ b/libavcodec/h264.c
@@ -91,7 +91,7 @@ static void h264_er_decode_mb(void *opaque, int ref, int mv_dir, int mv_type,
     fill_rectangle(sl->mv_cache[0][scan8[0]], 4, 4, 8,
                    pack16to32((*mv)[0][0][0], (*mv)[0][0][1]), 4);
     h->mb_mbaff =
-    h->mb_field_decoding_flag = 0;
+    sl->mb_field_decoding_flag = 0;
     ff_h264_hl_decode_mb(h, &h->slice_ctx[0]);
 }
 
diff --git a/libavcodec/h264.h b/libavcodec/h264.h
index 0b44b441e7..e5a6a17c50 100644
--- a/libavcodec/h264.h
+++ b/libavcodec/h264.h
@@ -401,6 +401,8 @@ typedef struct H264SliceContext {
     int mb_skip_run;
     int is_complex;
 
+    int mb_field_decoding_flag;
+
     int redundant_pic_count;
 
     /**
@@ -537,7 +539,6 @@ typedef struct H264Context {
 
     // interlacing specific flags
     int mb_aff_frame;
-    int mb_field_decoding_flag;
     int mb_mbaff;               ///< mb_aff_frame && mb_field_decoding_flag
     int picture_structure;
     int first_field;
diff --git a/libavcodec/h264_cabac.c b/libavcodec/h264_cabac.c
index 85fcf7f2a8..90dd9f9641 100644
--- a/libavcodec/h264_cabac.c
+++ b/libavcodec/h264_cabac.c
@@ -1288,7 +1288,7 @@ static int decode_cabac_field_decoding_flag(H264Context *h, H264SliceContext *sl
 
     unsigned long ctx = 0;
 
-    ctx += h->mb_field_decoding_flag & !!sl->mb_x; //for FMO:(s->current_picture.mb_type[mba_xy] >> 7) & (h->slice_table[mba_xy] == h->slice_num);
+    ctx += sl->mb_field_decoding_flag & !!sl->mb_x; //for FMO:(s->current_picture.mb_type[mba_xy] >> 7) & (h->slice_table[mba_xy] == h->slice_num);
     ctx += (h->cur_pic.mb_type[mbb_xy] >> 7) & (h->slice_table[mbb_xy] == sl->slice_num);
 
     return get_cabac_noinline( &sl->cabac, &(sl->cabac_state+70)[ctx] );
@@ -1337,9 +1337,9 @@ static int decode_cabac_mb_skip(H264Context *h, H264SliceContext *sl,
         mba_xy = mb_xy - 1;
         if( (mb_y&1)
             && h->slice_table[mba_xy] == sl->slice_num
-            && MB_FIELD(h) == !!IS_INTERLACED( h->cur_pic.mb_type[mba_xy] ) )
+            && MB_FIELD(sl) == !!IS_INTERLACED( h->cur_pic.mb_type[mba_xy] ) )
             mba_xy += h->mb_stride;
-        if (MB_FIELD(h)) {
+        if (MB_FIELD(sl)) {
             mbb_xy = mb_xy - h->mb_stride;
             if( !(mb_y&1)
                 && h->slice_table[mbb_xy] == sl->slice_num
@@ -1648,9 +1648,9 @@ decode_cabac_residual_internal(H264Context *h, H264SliceContext *sl,
 #endif
 
     significant_coeff_ctx_base = sl->cabac_state
-        + significant_coeff_flag_offset[MB_FIELD(h)][cat];
+        + significant_coeff_flag_offset[MB_FIELD(sl)][cat];
     last_coeff_ctx_base = sl->cabac_state
-        + last_coeff_flag_offset[MB_FIELD(h)][cat];
+        + last_coeff_flag_offset[MB_FIELD(sl)][cat];
     abs_level_m1_ctx_base = sl->cabac_state
         + coeff_abs_level_m1_offset[cat];
 
@@ -1670,7 +1670,7 @@ decode_cabac_residual_internal(H264Context *h, H264SliceContext *sl,
         if( last == max_coeff -1 ) {\
             index[coeff_count++] = last;\
         }
-        const uint8_t *sig_off = significant_coeff_flag_offset_8x8[MB_FIELD(h)];
+        const uint8_t *sig_off = significant_coeff_flag_offset_8x8[MB_FIELD(sl)];
 #ifdef decode_significance
         coeff_count = decode_significance_8x8(CC, significant_coeff_ctx_base, index,
                                                  last_coeff_ctx_base, sig_off);
@@ -1933,7 +1933,7 @@ int ff_h264_decode_mb_cabac(H264Context *h, H264SliceContext *sl)
                 h->cur_pic.mb_type[mb_xy] = MB_TYPE_SKIP;
                 sl->next_mb_skipped = decode_cabac_mb_skip(h, sl, sl->mb_x, sl->mb_y+1 );
                 if(!sl->next_mb_skipped)
-                    h->mb_mbaff = h->mb_field_decoding_flag = decode_cabac_field_decoding_flag(h, sl);
+                    h->mb_mbaff = sl->mb_field_decoding_flag = decode_cabac_field_decoding_flag(h, sl);
             }
 
             decode_mb_skip(h, sl);
@@ -1949,12 +1949,12 @@ int ff_h264_decode_mb_cabac(H264Context *h, H264SliceContext *sl)
     if (FRAME_MBAFF(h)) {
         if ((sl->mb_y & 1) == 0)
             h->mb_mbaff =
-            h->mb_field_decoding_flag = decode_cabac_field_decoding_flag(h, sl);
+            sl->mb_field_decoding_flag = decode_cabac_field_decoding_flag(h, sl);
     }
 
     sl->prev_mb_skipped = 0;
 
-    fill_decode_neighbors(h, sl, -(MB_FIELD(h)));
+    fill_decode_neighbors(h, sl, -(MB_FIELD(sl)));
 
     if (sl->slice_type_nos == AV_PICTURE_TYPE_B) {
         int ctx = 0;
@@ -2018,7 +2018,7 @@ decode_intra_mb:
         sl->intra16x16_pred_mode = i_mb_type_info[mb_type].pred_mode;
         mb_type= i_mb_type_info[mb_type].type;
     }
-    if(MB_FIELD(h))
+    if (MB_FIELD(sl))
         mb_type |= MB_TYPE_INTERLACED;
 
     h->slice_table[mb_xy] = sl->slice_num;
diff --git a/libavcodec/h264_cavlc.c b/libavcodec/h264_cavlc.c
index 4ccfb4ce1d..45e2096849 100644
--- a/libavcodec/h264_cavlc.c
+++ b/libavcodec/h264_cavlc.c
@@ -723,7 +723,7 @@ int ff_h264_decode_mb_cavlc(H264Context *h, H264SliceContext *sl)
         if (sl->mb_skip_run--) {
             if (FRAME_MBAFF(h) && (sl->mb_y & 1) == 0) {
                 if (sl->mb_skip_run == 0)
-                    h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&sl->gb);
+                    h->mb_mbaff = sl->mb_field_decoding_flag = get_bits1(&sl->gb);
             }
             decode_mb_skip(h, sl);
             return 0;
@@ -731,7 +731,7 @@ int ff_h264_decode_mb_cavlc(H264Context *h, H264SliceContext *sl)
     }
     if (FRAME_MBAFF(h)) {
         if ((sl->mb_y & 1) == 0)
-            h->mb_mbaff = h->mb_field_decoding_flag = get_bits1(&sl->gb);
+            h->mb_mbaff = sl->mb_field_decoding_flag = get_bits1(&sl->gb);
     }
 
     sl->prev_mb_skipped = 0;
@@ -768,7 +768,7 @@ decode_intra_mb:
         mb_type= i_mb_type_info[mb_type].type;
     }
 
-    if(MB_FIELD(h))
+    if (MB_FIELD(sl))
         mb_type |= MB_TYPE_INTERLACED;
 
     h->slice_table[mb_xy] = sl->slice_num;
diff --git a/libavcodec/h264_loopfilter.c b/libavcodec/h264_loopfilter.c
index f92cfc0beb..79aff5375b 100644
--- a/libavcodec/h264_loopfilter.c
+++ b/libavcodec/h264_loopfilter.c
@@ -757,9 +757,9 @@ void ff_h264_filter_mb(H264Context *h, H264SliceContext *sl,
                     {3+4*0, 3+4*1, 3+4*2, 3+4*3, 3+4*0, 3+4*1, 3+4*2, 3+4*3},
                 }
             };
-            const uint8_t *off= offset[MB_FIELD(h)][mb_y&1];
+            const uint8_t *off= offset[MB_FIELD(sl)][mb_y&1];
             for( i = 0; i < 8; i++ ) {
-                int j= MB_FIELD(h) ? i>>2 : i&1;
+                int j= MB_FIELD(sl) ? i>>2 : i&1;
                 int mbn_xy = sl->left_mb_xy[LEFT(j)];
                 int mbn_type = sl->left_type[LEFT(j)];
 
@@ -768,7 +768,7 @@ void ff_h264_filter_mb(H264Context *h, H264SliceContext *sl,
                 else{
                     bS[i] = 1 + !!(sl->non_zero_count_cache[12+8*(i>>1)] |
                          ((!h->pps.cabac && IS_8x8DCT(mbn_type)) ?
-                            (h->cbp_table[mbn_xy] & (((MB_FIELD(h) ? (i&2) : (mb_y&1)) ? 8 : 2) << 12))
+                            (h->cbp_table[mbn_xy] & (((MB_FIELD(sl) ? (i&2) : (mb_y&1)) ? 8 : 2) << 12))
                                                                        :
                             h->non_zero_count[mbn_xy][ off[i] ]));
                 }
@@ -792,7 +792,7 @@ void ff_h264_filter_mb(H264Context *h, H264SliceContext *sl,
         /* Filter edge */
         tprintf(h->avctx, "filter mb:%d/%d MBAFF, QPy:%d/%d, QPb:%d/%d QPr:%d/%d ls:%d uvls:%d", mb_x, mb_y, qp[0], qp[1], bqp[0], bqp[1], rqp[0], rqp[1], linesize, uvlinesize);
         { int i; for (i = 0; i < 8; i++) tprintf(h->avctx, " bS[%d]:%d", i, bS[i]); tprintf(h->avctx, "\n"); }
-        if (MB_FIELD(h)) {
+        if (MB_FIELD(sl)) {
             filter_mb_mbaff_edgev ( h, img_y                ,   linesize, bS  , 1, qp [0], a, b, 1 );
             filter_mb_mbaff_edgev ( h, img_y  + 8*  linesize,   linesize, bS+4, 1, qp [1], a, b, 1 );
             if (chroma){
diff --git a/libavcodec/h264_mb.c b/libavcodec/h264_mb.c
index d33d23792e..dcd65a9464 100644
--- a/libavcodec/h264_mb.c
+++ b/libavcodec/h264_mb.c
@@ -57,7 +57,7 @@ static inline void get_lowest_part_y(const H264Context *h, H264SliceContext *sl,
 {
     int my;
 
-    y_offset += 16 * (sl->mb_y >> MB_FIELD(h));
+    y_offset += 16 * (sl->mb_y >> MB_FIELD(sl));
 
     if (list0) {
         int ref_n = sl->ref_cache[0][scan8[n]];
@@ -225,7 +225,7 @@ static av_always_inline void mc_dir_part(const H264Context *h, H264SliceContext
     const int full_mx    = mx >> 2;
     const int full_my    = my >> 2;
     const int pic_width  = 16 * h->mb_width;
-    const int pic_height = 16 * h->mb_height >> MB_FIELD(h);
+    const int pic_height = 16 * h->mb_height >> MB_FIELD(sl);
     int ysh;
 
     if (mx & 7)
@@ -285,7 +285,7 @@ static av_always_inline void mc_dir_part(const H264Context *h, H264SliceContext
     }
 
     ysh = 3 - (chroma_idc == 2 /* yuv422 */);
-    if (chroma_idc == 1 /* yuv420 */ && MB_FIELD(h)) {
+    if (chroma_idc == 1 /* yuv420 */ && MB_FIELD(sl)) {
         // chroma offset when predicting from a field of opposite parity
         my  += 2 * ((sl->mb_y & 1) - (pic->reference - 1));
         emu |= (my >> 3) < 0 || (my >> 3) + 8 >= (pic_height >> 1);
@@ -346,7 +346,7 @@ static av_always_inline void mc_part_std(const H264Context *h, H264SliceContext
         dest_cr += (x_offset << pixel_shift) + y_offset * sl->mb_uvlinesize;
     }
     x_offset += 8 * sl->mb_x;
-    y_offset += 8 * (sl->mb_y >> MB_FIELD(h));
+    y_offset += 8 * (sl->mb_y >> MB_FIELD(sl));
 
     if (list0) {
         H264Picture *ref = &sl->ref_list[0][sl->ref_cache[0][scan8[n]]];
@@ -400,7 +400,7 @@ static av_always_inline void mc_part_weighted(const H264Context *h, H264SliceCon
         dest_cr      += (x_offset << pixel_shift) + y_offset * sl->mb_uvlinesize;
     }
     x_offset += 8 * sl->mb_x;
-    y_offset += 8 * (sl->mb_y >> MB_FIELD(h));
+    y_offset += 8 * (sl->mb_y >> MB_FIELD(sl));
 
     if (list0 && list1) {
         /* don't optimize for luma-only case, since B-frames usually
@@ -532,7 +532,7 @@ static av_always_inline void xchg_mb_border(const H264Context *h, H264SliceConte
         deblock_top     = sl->top_type;
     } else {
         deblock_topleft = (sl->mb_x > 0);
-        deblock_top     = (sl->mb_y > !!MB_FIELD(h));
+        deblock_top     = (sl->mb_y > !!MB_FIELD(sl));
     }
 
     src_y  -= linesize   + 1 + pixel_shift;
diff --git a/libavcodec/h264_mb_template.c b/libavcodec/h264_mb_template.c
index 52d60be93b..a03bdc2ac5 100644
--- a/libavcodec/h264_mb_template.c
+++ b/libavcodec/h264_mb_template.c
@@ -66,7 +66,7 @@ static av_noinline void FUNC(hl_decode_mb)(const H264Context *h, H264SliceContex
 
     h->list_counts[mb_xy] = sl->list_count;
 
-    if (!SIMPLE && MB_FIELD(h)) {
+    if (!SIMPLE && MB_FIELD(sl)) {
         linesize     = sl->mb_linesize = h->linesize * 2;
         uvlinesize   = sl->mb_uvlinesize = h->uvlinesize * 2;
         block_offset = &h->block_offset[48];
@@ -291,7 +291,7 @@ static av_noinline void FUNC(hl_decode_mb_444)(const H264Context *h, H264SliceCo
 
     h->list_counts[mb_xy] = sl->list_count;
 
-    if (!SIMPLE && MB_FIELD(h)) {
+    if (!SIMPLE && MB_FIELD(sl)) {
         linesize     = sl->mb_linesize = sl->mb_uvlinesize = h->linesize * 2;
         block_offset = &h->block_offset[48];
         if (mb_y & 1) // FIXME move out of this function?
diff --git a/libavcodec/h264_mvpred.h b/libavcodec/h264_mvpred.h
index 99bea07eec..e7db550f15 100644
--- a/libavcodec/h264_mvpred.h
+++ b/libavcodec/h264_mvpred.h
@@ -62,11 +62,11 @@ static av_always_inline int fetch_diagonal_mv(const H264Context *h, H264SliceCon
             AV_ZERO32(sl->mv_cache[list][scan8[0] - 2]);
             *C = sl->mv_cache[list][scan8[0] - 2];
 
-            if (!MB_FIELD(h) && IS_INTERLACED(sl->left_type[0])) {
+            if (!MB_FIELD(sl) && IS_INTERLACED(sl->left_type[0])) {
                 SET_DIAG_MV(* 2, >> 1, sl->left_mb_xy[0] + h->mb_stride,
                             (sl->mb_y & 1) * 2 + (i >> 5));
             }
-            if (MB_FIELD(h) && !IS_INTERLACED(sl->left_type[0])) {
+            if (MB_FIELD(sl) && !IS_INTERLACED(sl->left_type[0])) {
                 // left shift will turn LIST_NOT_USED into PART_NOT_AVAILABLE, but that's OK.
                 SET_DIAG_MV(/ 2, << 1, sl->left_mb_xy[i >= 36], ((i >> 2)) & 3);
             }
@@ -237,7 +237,7 @@ static av_always_inline void pred_8x16_motion(const H264Context *const h,
 
 #define FIX_MV_MBAFF(type, refn, mvn, idx)      \
     if (FRAME_MBAFF(h)) {                       \
-        if (MB_FIELD(h)) {                      \
+        if (MB_FIELD(sl)) {                     \
             if (!IS_INTERLACED(type)) {         \
                 refn <<= 1;                     \
                 AV_COPY32(mvbuf[idx], mvn);     \
@@ -366,7 +366,7 @@ static void fill_decode_neighbors(const H264Context *h, H264SliceContext *sl, in
 
     sl->topleft_partition = -1;
 
-    top_xy = mb_xy - (h->mb_stride << MB_FIELD(h));
+    top_xy = mb_xy - (h->mb_stride << MB_FIELD(sl));
 
     /* Wow, what a mess, why didn't they simplify the interlacing & intra
      * stuff, I can't imagine that these complex rules are worth it. */
@@ -767,7 +767,7 @@ static void fill_decode_caches(const H264Context *h, H264SliceContext *sl, int m
     MAP_F2F(scan8[0] - 1 + 3 * 8, left_type[LBOT])
 
             if (FRAME_MBAFF(h)) {
-                if (MB_FIELD(h)) {
+                if (MB_FIELD(sl)) {
 
 #define MAP_F2F(idx, mb_type)                                           \
     if (!IS_INTERLACED(mb_type) && sl->ref_cache[list][idx] >= 0) {     \
@@ -807,7 +807,7 @@ static void av_unused decode_mb_skip(const H264Context *h, H264SliceContext *sl)
 
     memset(h->non_zero_count[mb_xy], 0, 48);
 
-    if (MB_FIELD(h))
+    if (MB_FIELD(sl))
         mb_type |= MB_TYPE_INTERLACED;
 
     if (sl->slice_type_nos == AV_PICTURE_TYPE_B) {
diff --git a/libavcodec/h264_slice.c b/libavcodec/h264_slice.c
index 559c6a04e4..d81dd9077b 100644
--- a/libavcodec/h264_slice.c
+++ b/libavcodec/h264_slice.c
@@ -1553,7 +1553,7 @@ int ff_h264_decode_slice_header(H264Context *h, H264SliceContext *sl, H264Contex
     h->picture_structure = picture_structure;
     h->droppable         = droppable;
     h->frame_num         = frame_num;
-    h->mb_field_decoding_flag = picture_structure != PICT_FRAME;
+    sl->mb_field_decoding_flag = picture_structure != PICT_FRAME;
 
     if (h0->current_slice == 0) {
         /* Shorten frame num gaps so we don't have to allocate reference
@@ -2131,7 +2131,7 @@ static int fill_filter_caches(H264Context *h, H264SliceContext *sl, int mb_type)
     uint8_t *nnz;
     uint8_t *nnz_cache;
 
-    top_xy = mb_xy - (h->mb_stride << MB_FIELD(h));
+    top_xy = mb_xy - (h->mb_stride << MB_FIELD(sl));
 
     /* Wow, what a mess, why didn't they simplify the interlacing & intra
      * stuff, I can't imagine that these complex rules are worth it. */
@@ -2288,7 +2288,7 @@ static void loop_filter(H264Context *h, H264SliceContext *sl, int start_x, int e
 
                 if (FRAME_MBAFF(h))
                     h->mb_mbaff               =
-                    h->mb_field_decoding_flag = !!IS_INTERLACED(mb_type);
+                    sl->mb_field_decoding_flag = !!IS_INTERLACED(mb_type);
 
                 sl->mb_x = mb_x;
                 sl->mb_y = mb_y;
@@ -2302,7 +2302,7 @@ static void loop_filter(H264Context *h, H264SliceContext *sl, int start_x, int e
                           mb_y * h->uvlinesize * block_h;
                 // FIXME simplify above
 
-                if (MB_FIELD(h)) {
+                if (MB_FIELD(sl)) {
                     linesize   = sl->mb_linesize   = h->linesize   * 2;
                     uvlinesize = sl->mb_uvlinesize = h->uvlinesize * 2;
                     if (mb_y & 1) { // FIXME move out of this function?
@@ -2344,7 +2344,7 @@ static void predict_field_decoding_flag(H264Context *h, H264SliceContext *sl)
                       h->cur_pic.mb_type[mb_xy - 1] :
                       (h->slice_table[mb_xy - h->mb_stride] == sl->slice_num) ?
                       h->cur_pic.mb_type[mb_xy - h->mb_stride] : 0;
-    h->mb_mbaff     = h->mb_field_decoding_flag = IS_INTERLACED(mb_type) ? 1 : 0;
+    h->mb_mbaff     = sl->mb_field_decoding_flag = IS_INTERLACED(mb_type) ? 1 : 0;
 }
 
 /**