lavc: Add DSS SP decoder
[ffmpeg.git] / libavcodec / h264_refs.c
index a5b5d5c..03c1b9c 100644 (file)
@@ -2,57 +2,65 @@
  * H.26L/H.264/AVC/JVT/14496-10/... reference picture handling
  * Copyright (c) 2003 Michael Niedermayer <michaelni@gmx.at>
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
 /**
- * @file libavcodec/h264_refs.c
+ * @file
  * H.264 / AVC / MPEG4 part10  reference picture handling.
  * @author Michael Niedermayer <michaelni@gmx.at>
  */
 
+#include <inttypes.h>
+
 #include "internal.h"
-#include "dsputil.h"
 #include "avcodec.h"
 #include "h264.h"
 #include "golomb.h"
+#include "mpegutils.h"
 
-//#undef NDEBUG
 #include <assert.h>
 
+#define COPY_PICTURE(dst, src) \
+do {\
+    *(dst) = *(src);\
+    (dst)->f.extended_data = (dst)->f.data;\
+    (dst)->tf.f = &(dst)->f;\
+} while (0)
+
 
-static void pic_as_field(Picture *pic, const int parity){
+static void pic_as_field(H264Picture *pic, const int parity){
     int i;
     for (i = 0; i < 4; ++i) {
         if (parity == PICT_BOTTOM_FIELD)
-            pic->data[i] += pic->linesize[i];
-        pic->reference = parity;
-        pic->linesize[i] *= 2;
+            pic->f.data[i] += pic->f.linesize[i];
+        pic->reference      = parity;
+        pic->f.linesize[i] *= 2;
     }
     pic->poc= pic->field_poc[parity == PICT_BOTTOM_FIELD];
 }
 
-static int split_field_copy(Picture *dest, Picture *src,
-                            int parity, int id_add){
+static int split_field_copy(H264Picture *dest, H264Picture *src, int parity, int id_add)
+{
     int match = !!(src->reference & parity);
 
     if (match) {
-        *dest = *src;
-        if(parity != PICT_FRAME){
+        COPY_PICTURE(dest, src);
+        if (parity != PICT_FRAME) {
             pic_as_field(dest, parity);
             dest->pic_id *= 2;
             dest->pic_id += id_add;
@@ -62,95 +70,116 @@ static int split_field_copy(Picture *dest, Picture *src,
     return match;
 }
 
-static int build_def_list(Picture *def, Picture **in, int len, int is_long, int sel){
-    int i[2]={0};
-    int index=0;
+static int build_def_list(H264Picture *def, int def_len,
+                          H264Picture **in, int len, int is_long, int sel)
+{
+    int  i[2] = { 0 };
+    int index = 0;
 
-    while(i[0]<len || i[1]<len){
-        while(i[0]<len && !(in[ i[0] ] && (in[ i[0] ]->reference & sel)))
+    while ((i[0] < len || i[1] < len) && index < def_len) {
+        while (i[0] < len && !(in[i[0]] && (in[i[0]]->reference & sel)))
             i[0]++;
-        while(i[1]<len && !(in[ i[1] ] && (in[ i[1] ]->reference & (sel^3))))
+        while (i[1] < len && !(in[i[1]] && (in[i[1]]->reference & (sel ^ 3))))
             i[1]++;
-        if(i[0] < len){
-            in[ i[0] ]->pic_id= is_long ? i[0] : in[ i[0] ]->frame_num;
-            split_field_copy(&def[index++], in[ i[0]++ ], sel  , 1);
+        if (i[0] < len && index < def_len) {
+            in[i[0]]->pic_id = is_long ? i[0] : in[i[0]]->frame_num;
+            split_field_copy(&def[index++], in[i[0]++], sel, 1);
         }
-        if(i[1] < len){
-            in[ i[1] ]->pic_id= is_long ? i[1] : in[ i[1] ]->frame_num;
-            split_field_copy(&def[index++], in[ i[1]++ ], sel^3, 0);
+        if (i[1] < len && index < def_len) {
+            in[i[1]]->pic_id = is_long ? i[1] : in[i[1]]->frame_num;
+            split_field_copy(&def[index++], in[i[1]++], sel ^ 3, 0);
         }
     }
 
     return index;
 }
 
-static int add_sorted(Picture **sorted, Picture **src, int len, int limit, int dir){
+static int add_sorted(H264Picture **sorted, H264Picture **src, int len, int limit, int dir)
+{
     int i, best_poc;
-    int out_i= 0;
+    int out_i = 0;
 
-    for(;;){
-        best_poc= dir ? INT_MIN : INT_MAX;
+    for (;;) {
+        best_poc = dir ? INT_MIN : INT_MAX;
 
-        for(i=0; i<len; i++){
-            const int poc= src[i]->poc;
-            if(((poc > limit) ^ dir) && ((poc < best_poc) ^ dir)){
-                best_poc= poc;
-                sorted[out_i]= src[i];
+        for (i = 0; i < len; i++) {
+            const int poc = src[i]->poc;
+            if (((poc > limit) ^ dir) && ((poc < best_poc) ^ dir)) {
+                best_poc      = poc;
+                sorted[out_i] = src[i];
             }
         }
-        if(best_poc == (dir ? INT_MIN : INT_MAX))
+        if (best_poc == (dir ? INT_MIN : INT_MAX))
             break;
-        limit= sorted[out_i++]->poc - dir;
+        limit = sorted[out_i++]->poc - dir;
     }
     return out_i;
 }
 
-int ff_h264_fill_default_ref_list(H264Context *h){
-    MpegEncContext * const s = &h->s;
+int ff_h264_fill_default_ref_list(H264Context *h)
+{
     int i, len;
 
-    if(h->slice_type_nos==FF_B_TYPE){
-        Picture *sorted[32];
+    if (h->slice_type_nos == AV_PICTURE_TYPE_B) {
+        H264Picture *sorted[32];
         int cur_poc, list;
         int lens[2];
 
-        if(FIELD_PICTURE)
-            cur_poc= s->current_picture_ptr->field_poc[ s->picture_structure == PICT_BOTTOM_FIELD ];
+        if (FIELD_PICTURE(h))
+            cur_poc = h->cur_pic_ptr->field_poc[h->picture_structure == PICT_BOTTOM_FIELD];
         else
-            cur_poc= s->current_picture_ptr->poc;
-
-        for(list= 0; list<2; list++){
-            len= add_sorted(sorted    , h->short_ref, h->short_ref_count, cur_poc, 1^list);
-            len+=add_sorted(sorted+len, h->short_ref, h->short_ref_count, cur_poc, 0^list);
-            assert(len<=32);
-            len= build_def_list(h->default_ref_list[list]    , sorted     , len, 0, s->picture_structure);
-            len+=build_def_list(h->default_ref_list[list]+len, h->long_ref, 16 , 1, s->picture_structure);
-            assert(len<=32);
-
-            if(len < h->ref_count[list])
-                memset(&h->default_ref_list[list][len], 0, sizeof(Picture)*(h->ref_count[list] - len));
-            lens[list]= len;
+            cur_poc = h->cur_pic_ptr->poc;
+
+        for (list = 0; list < 2; list++) {
+            len  = add_sorted(sorted,       h->short_ref, h->short_ref_count, cur_poc, 1 ^ list);
+            len += add_sorted(sorted + len, h->short_ref, h->short_ref_count, cur_poc, 0 ^ list);
+            assert(len <= 32);
+
+            len  = build_def_list(h->default_ref_list[list], FF_ARRAY_ELEMS(h->default_ref_list[0]),
+                                  sorted, len, 0, h->picture_structure);
+            len += build_def_list(h->default_ref_list[list] + len,
+                                  FF_ARRAY_ELEMS(h->default_ref_list[0]) - len,
+                                  h->long_ref, 16, 1, h->picture_structure);
+
+            if (len < h->ref_count[list])
+                memset(&h->default_ref_list[list][len], 0, sizeof(H264Picture) * (h->ref_count[list] - len));
+            lens[list] = len;
         }
 
-        if(lens[0] == lens[1] && lens[1] > 1){
-            for(i=0; h->default_ref_list[0][i].data[0] == h->default_ref_list[1][i].data[0] && i<lens[0]; i++);
-            if(i == lens[0])
-                FFSWAP(Picture, h->default_ref_list[1][0], h->default_ref_list[1][1]);
+        if (lens[0] == lens[1] && lens[1] > 1) {
+            for (i = 0; i < lens[0] &&
+                        h->default_ref_list[0][i].f.buf[0]->buffer ==
+                        h->default_ref_list[1][i].f.buf[0]->buffer; i++);
+            if (i == lens[0]) {
+                H264Picture tmp;
+                COPY_PICTURE(&tmp, &h->default_ref_list[1][0]);
+                COPY_PICTURE(&h->default_ref_list[1][0], &h->default_ref_list[1][1]);
+                COPY_PICTURE(&h->default_ref_list[1][1], &tmp);
+            }
         }
-    }else{
-        len = build_def_list(h->default_ref_list[0]    , h->short_ref, h->short_ref_count, 0, s->picture_structure);
-        len+= build_def_list(h->default_ref_list[0]+len, h-> long_ref, 16                , 1, s->picture_structure);
-        assert(len <= 32);
-        if(len < h->ref_count[0])
-            memset(&h->default_ref_list[0][len], 0, sizeof(Picture)*(h->ref_count[0] - len));
+    } else {
+        len  = build_def_list(h->default_ref_list[0], FF_ARRAY_ELEMS(h->default_ref_list[0]),
+                              h->short_ref, h->short_ref_count, 0, h->picture_structure);
+        len += build_def_list(h->default_ref_list[0] + len,
+                              FF_ARRAY_ELEMS(h->default_ref_list[0]) - len,
+                              h-> long_ref, 16, 1, h->picture_structure);
+
+        if (len < h->ref_count[0])
+            memset(&h->default_ref_list[0][len], 0, sizeof(H264Picture) * (h->ref_count[0] - len));
     }
 #ifdef TRACE
-    for (i=0; i<h->ref_count[0]; i++) {
-        tprintf(h->s.avctx, "List0: %s fn:%d 0x%p\n", (h->default_ref_list[0][i].long_ref ? "LT" : "ST"), h->default_ref_list[0][i].pic_id, h->default_ref_list[0][i].data[0]);
+    for (i = 0; i < h->ref_count[0]; i++) {
+        tprintf(h->avctx, "List0: %s fn:%d 0x%p\n",
+                (h->default_ref_list[0][i].long_ref ? "LT" : "ST"),
+                h->default_ref_list[0][i].pic_id,
+                h->default_ref_list[0][i].f.data[0]);
     }
-    if(h->slice_type_nos==FF_B_TYPE){
-        for (i=0; i<h->ref_count[1]; i++) {
-            tprintf(h->s.avctx, "List1: %s fn:%d 0x%p\n", (h->default_ref_list[1][i].long_ref ? "LT" : "ST"), h->default_ref_list[1][i].pic_id, h->default_ref_list[1][i].data[0]);
+    if (h->slice_type_nos == AV_PICTURE_TYPE_B) {
+        for (i = 0; i < h->ref_count[1]; i++) {
+            tprintf(h->avctx, "List1: %s fn:%d 0x%p\n",
+                    (h->default_ref_list[1][i].long_ref ? "LT" : "ST"),
+                    h->default_ref_list[1][i].pic_id,
+                    h->default_ref_list[1][i].f.data[0]);
         }
     }
 #endif
@@ -170,11 +199,10 @@ static void print_long_term(H264Context *h);
  * @return frame number (short term) or long term index of picture
  *         described by pic_num
  */
-static int pic_num_extract(H264Context *h, int pic_num, int *structure){
-    MpegEncContext * const s = &h->s;
-
-    *structure = s->picture_structure;
-    if(FIELD_PICTURE){
+static int pic_num_extract(H264Context *h, int pic_num, int *structure)
+{
+    *structure = h->picture_structure;
+    if (FIELD_PICTURE(h)) {
         if (!(pic_num & 1))
             /* opposite field */
             *structure ^= PICT_FRAME;
@@ -184,111 +212,122 @@ static int pic_num_extract(H264Context *h, int pic_num, int *structure){
     return pic_num;
 }
 
-int ff_h264_decode_ref_pic_list_reordering(H264Context *h){
-    MpegEncContext * const s = &h->s;
-    int list, index, pic_structure;
+int ff_h264_decode_ref_pic_list_reordering(H264Context *h)
+{
+    int list, index, pic_structure, i;
 
     print_short_term(h);
     print_long_term(h);
 
-    for(list=0; list<h->list_count; list++){
-        memcpy(h->ref_list[list], h->default_ref_list[list], sizeof(Picture)*h->ref_count[list]);
+    for (list = 0; list < h->list_count; list++) {
+        for (i = 0; i < h->ref_count[list]; i++)
+            COPY_PICTURE(&h->ref_list[list][i], &h->default_ref_list[list][i]);
 
-        if(get_bits1(&s->gb)){
-            int pred= h->curr_pic_num;
+        if (get_bits1(&h->gb)) {    // ref_pic_list_modification_flag_l[01]
+            int pred = h->curr_pic_num;
 
-            for(index=0; ; index++){
-                unsigned int reordering_of_pic_nums_idc= get_ue_golomb_31(&s->gb);
+            for (index = 0; ; index++) {
+                unsigned int modification_of_pic_nums_idc = get_ue_golomb_31(&h->gb);
                 unsigned int pic_id;
                 int i;
-                Picture *ref = NULL;
+                H264Picture *ref = NULL;
 
-                if(reordering_of_pic_nums_idc==3)
+                if (modification_of_pic_nums_idc == 3)
                     break;
 
-                if(index >= h->ref_count[list]){
-                    av_log(h->s.avctx, AV_LOG_ERROR, "reference count overflow\n");
+                if (index >= h->ref_count[list]) {
+                    av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n");
                     return -1;
                 }
 
-                if(reordering_of_pic_nums_idc<3){
-                    if(reordering_of_pic_nums_idc<2){
-                        const unsigned int abs_diff_pic_num= get_ue_golomb(&s->gb) + 1;
-                        int frame_num;
-
-                        if(abs_diff_pic_num > h->max_pic_num){
-                            av_log(h->s.avctx, AV_LOG_ERROR, "abs_diff_pic_num overflow\n");
-                            return -1;
-                        }
-
-                        if(reordering_of_pic_nums_idc == 0) pred-= abs_diff_pic_num;
-                        else                                pred+= abs_diff_pic_num;
-                        pred &= h->max_pic_num - 1;
-
-                        frame_num = pic_num_extract(h, pred, &pic_structure);
-
-                        for(i= h->short_ref_count-1; i>=0; i--){
-                            ref = h->short_ref[i];
-                            assert(ref->reference);
-                            assert(!ref->long_ref);
-                            if(
-                                   ref->frame_num == frame_num &&
-                                   (ref->reference & pic_structure)
-                              )
-                                break;
-                        }
-                        if(i>=0)
-                            ref->pic_id= pred;
-                    }else{
-                        int long_idx;
-                        pic_id= get_ue_golomb(&s->gb); //long_term_pic_idx
-
-                        long_idx= pic_num_extract(h, pic_id, &pic_structure);
-
-                        if(long_idx>31){
-                            av_log(h->s.avctx, AV_LOG_ERROR, "long_term_pic_idx overflow\n");
-                            return -1;
-                        }
-                        ref = h->long_ref[long_idx];
-                        assert(!(ref && !ref->reference));
-                        if(ref && (ref->reference & pic_structure)){
-                            ref->pic_id= pic_id;
-                            assert(ref->long_ref);
-                            i=0;
-                        }else{
-                            i=-1;
-                        }
+                switch (modification_of_pic_nums_idc) {
+                case 0:
+                case 1: {
+                    const unsigned int abs_diff_pic_num = get_ue_golomb(&h->gb) + 1;
+                    int frame_num;
+
+                    if (abs_diff_pic_num > h->max_pic_num) {
+                        av_log(h->avctx, AV_LOG_ERROR,
+                               "abs_diff_pic_num overflow\n");
+                        return AVERROR_INVALIDDATA;
                     }
 
-                    if (i < 0) {
-                        av_log(h->s.avctx, AV_LOG_ERROR, "reference picture missing during reorder\n");
-                        memset(&h->ref_list[list][index], 0, sizeof(Picture)); //FIXME
+                    if (modification_of_pic_nums_idc == 0)
+                        pred -= abs_diff_pic_num;
+                    else
+                        pred += abs_diff_pic_num;
+                    pred &= h->max_pic_num - 1;
+
+                    frame_num = pic_num_extract(h, pred, &pic_structure);
+
+                    for (i = h->short_ref_count - 1; i >= 0; i--) {
+                        ref = h->short_ref[i];
+                        assert(ref->reference);
+                        assert(!ref->long_ref);
+                        if (ref->frame_num == frame_num &&
+                            (ref->reference & pic_structure))
+                            break;
+                    }
+                    if (i >= 0)
+                        ref->pic_id = pred;
+                    break;
+                }
+                case 2: {
+                    int long_idx;
+                    pic_id = get_ue_golomb(&h->gb); // long_term_pic_idx
+
+                    long_idx = pic_num_extract(h, pic_id, &pic_structure);
+
+                    if (long_idx > 31) {
+                        av_log(h->avctx, AV_LOG_ERROR,
+                               "long_term_pic_idx overflow\n");
+                        return AVERROR_INVALIDDATA;
+                    }
+                    ref = h->long_ref[long_idx];
+                    assert(!(ref && !ref->reference));
+                    if (ref && (ref->reference & pic_structure)) {
+                        ref->pic_id = pic_id;
+                        assert(ref->long_ref);
+                        i = 0;
                     } else {
-                        for(i=index; i+1<h->ref_count[list]; i++){
-                            if(ref->long_ref == h->ref_list[list][i].long_ref && ref->pic_id == h->ref_list[list][i].pic_id)
-                                break;
-                        }
-                        for(; i > index; i--){
-                            h->ref_list[list][i]= h->ref_list[list][i-1];
-                        }
-                        h->ref_list[list][index]= *ref;
-                        if (FIELD_PICTURE){
-                            pic_as_field(&h->ref_list[list][index], pic_structure);
-                        }
+                        i = -1;
+                    }
+                    break;
+                }
+                default:
+                    av_log(h->avctx, AV_LOG_ERROR,
+                           "illegal modification_of_pic_nums_idc %u\n",
+                           modification_of_pic_nums_idc);
+                    return AVERROR_INVALIDDATA;
+                }
+
+                if (i < 0) {
+                    av_log(h->avctx, AV_LOG_ERROR,
+                           "reference picture missing during reorder\n");
+                    memset(&h->ref_list[list][index], 0, sizeof(H264Picture)); // FIXME
+                } else {
+                    for (i = index; i + 1 < h->ref_count[list]; i++) {
+                        if (ref->long_ref == h->ref_list[list][i].long_ref &&
+                            ref->pic_id   == h->ref_list[list][i].pic_id)
+                            break;
+                    }
+                    for (; i > index; i--) {
+                        COPY_PICTURE(&h->ref_list[list][i], &h->ref_list[list][i - 1]);
+                    }
+                    COPY_PICTURE(&h->ref_list[list][index], ref);
+                    if (FIELD_PICTURE(h)) {
+                        pic_as_field(&h->ref_list[list][index], pic_structure);
                     }
-                }else{
-                    av_log(h->s.avctx, AV_LOG_ERROR, "illegal reordering_of_pic_nums_idc\n");
-                    return -1;
                 }
             }
         }
     }
-    for(list=0; list<h->list_count; list++){
-        for(index= 0; index < h->ref_count[list]; index++){
-            if(!h->ref_list[list][index].data[0]){
-                av_log(h->s.avctx, AV_LOG_ERROR, "Missing reference picture\n");
-                if(h->default_ref_list[list][0].data[0])
-                    h->ref_list[list][index]= h->default_ref_list[list][0];
+    for (list = 0; list < h->list_count; list++) {
+        for (index = 0; index < h->ref_count[list]; index++) {
+            if (!h->ref_list[list][index].f.buf[0]) {
+                av_log(h->avctx, AV_LOG_ERROR, "Missing reference picture\n");
+                if (h->default_ref_list[list][0].f.buf[0])
+                    COPY_PICTURE(&h->ref_list[list][index], &h->default_ref_list[list][0]);
                 else
                     return -1;
             }
@@ -298,28 +337,29 @@ int ff_h264_decode_ref_pic_list_reordering(H264Context *h){
     return 0;
 }
 
-void ff_h264_fill_mbaff_ref_list(H264Context *h){
+void ff_h264_fill_mbaff_ref_list(H264Context *h)
+{
     int list, i, j;
-    for(list=0; list<2; list++){ //FIXME try list_count
-        for(i=0; i<h->ref_count[list]; i++){
-            Picture *frame = &h->ref_list[list][i];
-            Picture *field = &h->ref_list[list][16+2*i];
-            field[0] = *frame;
-            for(j=0; j<3; j++)
-                field[0].linesize[j] <<= 1;
+    for (list = 0; list < 2; list++) { //FIXME try list_count
+        for (i = 0; i < h->ref_count[list]; i++) {
+            H264Picture *frame = &h->ref_list[list][i];
+            H264Picture *field = &h->ref_list[list][16 + 2 * i];
+            COPY_PICTURE(field, frame);
+            for (j = 0; j < 3; j++)
+                field[0].f.linesize[j] <<= 1;
             field[0].reference = PICT_TOP_FIELD;
-            field[0].poc= field[0].field_poc[0];
-            field[1] = field[0];
-            for(j=0; j<3; j++)
-                field[1].data[j] += frame->linesize[j];
+            field[0].poc       = field[0].field_poc[0];
+            COPY_PICTURE(field + 1, field);
+            for (j = 0; j < 3; j++)
+                field[1].f.data[j] += frame->f.linesize[j];
             field[1].reference = PICT_BOTTOM_FIELD;
-            field[1].poc= field[1].field_poc[1];
+            field[1].poc       = field[1].field_poc[1];
 
-            h->luma_weight[16+2*i][list][0] = h->luma_weight[16+2*i+1][list][0] = h->luma_weight[i][list][0];
-            h->luma_weight[16+2*i][list][1] = h->luma_weight[16+2*i+1][list][1] = h->luma_weight[i][list][1];
-            for(j=0; j<2; j++){
-                h->chroma_weight[16+2*i][list][j][0] = h->chroma_weight[16+2*i+1][list][j][0] = h->chroma_weight[i][list][j][0];
-                h->chroma_weight[16+2*i][list][j][1] = h->chroma_weight[16+2*i+1][list][j][1] = h->chroma_weight[i][list][j][1];
+            h->luma_weight[16 + 2 * i][list][0] = h->luma_weight[16 + 2 * i + 1][list][0] = h->luma_weight[i][list][0];
+            h->luma_weight[16 + 2 * i][list][1] = h->luma_weight[16 + 2 * i + 1][list][1] = h->luma_weight[i][list][1];
+            for (j = 0; j < 2; j++) {
+                h->chroma_weight[16 + 2 * i][list][j][0] = h->chroma_weight[16 + 2 * i + 1][list][j][0] = h->chroma_weight[i][list][j][0];
+                h->chroma_weight[16 + 2 * i][list][j][1] = h->chroma_weight[16 + 2 * i + 1][list][j][1] = h->chroma_weight[i][list][j][1];
             }
         }
     }
@@ -336,14 +376,15 @@ void ff_h264_fill_mbaff_ref_list(H264Context *h){
  *         for display purposes) zero if one of the fields remains in
  *         reference
  */
-static inline int unreference_pic(H264Context *h, Picture *pic, int refmask){
+static inline int unreference_pic(H264Context *h, H264Picture *pic, int refmask)
+{
     int i;
     if (pic->reference &= refmask) {
         return 0;
     } else {
         for(i = 0; h->delayed_pic[i]; i++)
             if(pic == h->delayed_pic[i]){
-                pic->reference=DELAYED_PIC_REF;
+                pic->reference = DELAYED_PIC_REF;
                 break;
             }
         return 1;
@@ -351,22 +392,22 @@ static inline int unreference_pic(H264Context *h, Picture *pic, int refmask){
 }
 
 /**
- * Find a Picture in the short term reference list by frame number.
+ * Find a H264Picture in the short term reference list by frame number.
  * @param frame_num frame number to search for
  * @param idx the index into h->short_ref where returned picture is found
  *            undefined if no picture found.
  * @return pointer to the found picture, or NULL if no pic with the provided
  *                 frame number is found
  */
-static Picture * find_short(H264Context *h, int frame_num, int *idx){
-    MpegEncContext * const s = &h->s;
+static H264Picture *find_short(H264Context *h, int frame_num, int *idx)
+{
     int i;
 
-    for(i=0; i<h->short_ref_count; i++){
-        Picture *pic= h->short_ref[i];
-        if(s->avctx->debug&FF_DEBUG_MMCO)
-            av_log(h->s.avctx, AV_LOG_DEBUG, "%d %d %p\n", i, pic->frame_num, pic);
-        if(pic->frame_num == frame_num) {
+    for (i = 0; i < h->short_ref_count; i++) {
+        H264Picture *pic = h->short_ref[i];
+        if (h->avctx->debug & FF_DEBUG_MMCO)
+            av_log(h->avctx, AV_LOG_DEBUG, "%d %d %p\n", i, pic->frame_num, pic);
+        if (pic->frame_num == frame_num) {
             *idx = i;
             return pic;
         }
@@ -380,29 +421,31 @@ static Picture * find_short(H264Context *h, int frame_num, int *idx){
  * to be valid. Other list entries are shifted down.
  * @param i index into h->short_ref of picture to remove.
  */
-static void remove_short_at_index(H264Context *h, int i){
+static void remove_short_at_index(H264Context *h, int i)
+{
     assert(i >= 0 && i < h->short_ref_count);
-    h->short_ref[i]= NULL;
+    h->short_ref[i] = NULL;
     if (--h->short_ref_count)
-        memmove(&h->short_ref[i], &h->short_ref[i+1], (h->short_ref_count - i)*sizeof(Picture*));
+        memmove(&h->short_ref[i], &h->short_ref[i + 1],
+                (h->short_ref_count - i) * sizeof(H264Picture*));
 }
 
 /**
  *
  * @return the removed picture or NULL if an error occurs
  */
-static Picture * remove_short(H264Context *h, int frame_num, int ref_mask){
-    MpegEncContext * const s = &h->s;
-    Picture *pic;
+static H264Picture *remove_short(H264Context *h, int frame_num, int ref_mask)
+{
+    H264Picture *pic;
     int i;
 
-    if(s->avctx->debug&FF_DEBUG_MMCO)
-        av_log(h->s.avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count);
+    if (h->avctx->debug & FF_DEBUG_MMCO)
+        av_log(h->avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count);
 
     pic = find_short(h, frame_num, &i);
-    if (pic){
-        if(unreference_pic(h, pic, ref_mask))
-        remove_short_at_index(h, i);
+    if (pic) {
+        if (unreference_pic(h, pic, ref_mask))
+            remove_short_at_index(h, i);
     }
 
     return pic;
@@ -413,15 +456,16 @@ static Picture * remove_short(H264Context *h, int frame_num, int ref_mask){
  * that list.
  * @return the removed picture or NULL if an error occurs
  */
-static Picture * remove_long(H264Context *h, int i, int ref_mask){
-    Picture *pic;
+static H264Picture *remove_long(H264Context *h, int i, int ref_mask)
+{
+    H264Picture *pic;
 
-    pic= h->long_ref[i];
-    if (pic){
-        if(unreference_pic(h, pic, ref_mask)){
+    pic = h->long_ref[i];
+    if (pic) {
+        if (unreference_pic(h, pic, ref_mask)) {
             assert(h->long_ref[i]->long_ref == 1);
-            h->long_ref[i]->long_ref= 0;
-            h->long_ref[i]= NULL;
+            h->long_ref[i]->long_ref = 0;
+            h->long_ref[i]           = NULL;
             h->long_ref_count--;
         }
     }
@@ -429,31 +473,34 @@ static Picture * remove_long(H264Context *h, int i, int ref_mask){
     return pic;
 }
 
-void ff_h264_remove_all_refs(H264Context *h){
+void ff_h264_remove_all_refs(H264Context *h)
+{
     int i;
 
-    for(i=0; i<16; i++){
+    for (i = 0; i < 16; i++) {
         remove_long(h, i, 0);
     }
-    assert(h->long_ref_count==0);
+    assert(h->long_ref_count == 0);
 
-    for(i=0; i<h->short_ref_count; i++){
+    for (i = 0; i < h->short_ref_count; i++) {
         unreference_pic(h, h->short_ref[i], 0);
-        h->short_ref[i]= NULL;
+        h->short_ref[i] = NULL;
     }
-    h->short_ref_count=0;
+    h->short_ref_count = 0;
 }
 
 /**
  * print short term list
  */
-static void print_short_term(H264Context *h) {
+static void print_short_term(H264Context *h)
+{
     uint32_t i;
-    if(h->s.avctx->debug&FF_DEBUG_MMCO) {
-        av_log(h->s.avctx, AV_LOG_DEBUG, "short term list:\n");
-        for(i=0; i<h->short_ref_count; i++){
-            Picture *pic= h->short_ref[i];
-            av_log(h->s.avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n", i, pic->frame_num, pic->poc, pic->data[0]);
+    if (h->avctx->debug & FF_DEBUG_MMCO) {
+        av_log(h->avctx, AV_LOG_DEBUG, "short term list:\n");
+        for (i = 0; i < h->short_ref_count; i++) {
+            H264Picture *pic = h->short_ref[i];
+            av_log(h->avctx, AV_LOG_DEBUG, "%"PRIu32" fn:%d poc:%d %p\n",
+                   i, pic->frame_num, pic->poc, pic->f.data[0]);
         }
     }
 }
@@ -461,49 +508,102 @@ static void print_short_term(H264Context *h) {
 /**
  * print long term list
  */
-static void print_long_term(H264Context *h) {
+static void print_long_term(H264Context *h)
+{
     uint32_t i;
-    if(h->s.avctx->debug&FF_DEBUG_MMCO) {
-        av_log(h->s.avctx, AV_LOG_DEBUG, "long term list:\n");
-        for(i = 0; i < 16; i++){
-            Picture *pic= h->long_ref[i];
+    if (h->avctx->debug & FF_DEBUG_MMCO) {
+        av_log(h->avctx, AV_LOG_DEBUG, "long term list:\n");
+        for (i = 0; i < 16; i++) {
+            H264Picture *pic = h->long_ref[i];
             if (pic) {
-                av_log(h->s.avctx, AV_LOG_DEBUG, "%d fn:%d poc:%d %p\n", i, pic->frame_num, pic->poc, pic->data[0]);
+                av_log(h->avctx, AV_LOG_DEBUG, "%"PRIu32" fn:%d poc:%d %p\n",
+                       i, pic->frame_num, pic->poc, pic->f.data[0]);
             }
         }
     }
 }
 
-int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
-    MpegEncContext * const s = &h->s;
+static int check_opcodes(MMCO *mmco1, MMCO *mmco2, int n_mmcos)
+{
+    int i;
+
+    for (i = 0; i < n_mmcos; i++) {
+        if (mmco1[i].opcode != mmco2[i].opcode)
+            return -1;
+    }
+
+    return 0;
+}
+
+int ff_generate_sliding_window_mmcos(H264Context *h, int first_slice)
+{
+    MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = first_slice ? h->mmco : mmco_temp;
+    int mmco_index = 0, i = 0;
+
+    assert(h->long_ref_count + h->short_ref_count <= h->sps.ref_frame_count);
+
+    if (h->short_ref_count &&
+        h->long_ref_count + h->short_ref_count == h->sps.ref_frame_count &&
+        !(FIELD_PICTURE(h) && !h->first_field && h->cur_pic_ptr->reference)) {
+        mmco[0].opcode        = MMCO_SHORT2UNUSED;
+        mmco[0].short_pic_num = h->short_ref[h->short_ref_count - 1]->frame_num;
+        mmco_index            = 1;
+        if (FIELD_PICTURE(h)) {
+            mmco[0].short_pic_num *= 2;
+            mmco[1].opcode         = MMCO_SHORT2UNUSED;
+            mmco[1].short_pic_num  = mmco[0].short_pic_num + 1;
+            mmco_index             = 2;
+        }
+    }
+
+    if (first_slice) {
+        h->mmco_index = mmco_index;
+    } else if (!first_slice && mmco_index >= 0 &&
+               (mmco_index != h->mmco_index ||
+                (i = check_opcodes(h->mmco, mmco_temp, mmco_index)))) {
+        av_log(h->avctx, AV_LOG_ERROR,
+               "Inconsistent MMCO state between slices [%d, %d, %d]\n",
+               mmco_index, h->mmco_index, i);
+        return AVERROR_INVALIDDATA;
+    }
+    return 0;
+}
+
+int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count)
+{
     int i, av_uninit(j);
-    int current_ref_assigned=0;
-    Picture *av_uninit(pic);
+    int current_ref_assigned = 0, err = 0;
+    H264Picture *av_uninit(pic);
 
-    if((s->avctx->debug&FF_DEBUG_MMCO) && mmco_count==0)
-        av_log(h->s.avctx, AV_LOG_DEBUG, "no mmco here\n");
+    if ((h->avctx->debug & FF_DEBUG_MMCO) && mmco_count == 0)
+        av_log(h->avctx, AV_LOG_DEBUG, "no mmco here\n");
 
-    for(i=0; i<mmco_count; i++){
+    for (i = 0; i < mmco_count; i++) {
         int av_uninit(structure), av_uninit(frame_num);
-        if(s->avctx->debug&FF_DEBUG_MMCO)
-            av_log(h->s.avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode, h->mmco[i].short_pic_num, h->mmco[i].long_arg);
+        if (h->avctx->debug & FF_DEBUG_MMCO)
+            av_log(h->avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode,
+                   h->mmco[i].short_pic_num, h->mmco[i].long_arg);
 
-        if(   mmco[i].opcode == MMCO_SHORT2UNUSED
-           || mmco[i].opcode == MMCO_SHORT2LONG){
+        if (mmco[i].opcode == MMCO_SHORT2UNUSED ||
+            mmco[i].opcode == MMCO_SHORT2LONG) {
             frame_num = pic_num_extract(h, mmco[i].short_pic_num, &structure);
-            pic = find_short(h, frame_num, &j);
-            if(!pic){
-                if(mmco[i].opcode != MMCO_SHORT2LONG || !h->long_ref[mmco[i].long_arg]
-                   || h->long_ref[mmco[i].long_arg]->frame_num != frame_num)
-                av_log(h->s.avctx, AV_LOG_ERROR, "mmco: unref short failure\n");
+            pic       = find_short(h, frame_num, &j);
+            if (!pic) {
+                if (mmco[i].opcode != MMCO_SHORT2LONG ||
+                    !h->long_ref[mmco[i].long_arg]    ||
+                    h->long_ref[mmco[i].long_arg]->frame_num != frame_num) {
+                    av_log(h->avctx, AV_LOG_ERROR, "mmco: unref short failure\n");
+                    err = AVERROR_INVALIDDATA;
+                }
                 continue;
             }
         }
 
-        switch(mmco[i].opcode){
+        switch (mmco[i].opcode) {
         case MMCO_SHORT2UNUSED:
-            if(s->avctx->debug&FF_DEBUG_MMCO)
-                av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: unref short %d count %d\n", h->mmco[i].short_pic_num, h->short_ref_count);
+            if (h->avctx->debug & FF_DEBUG_MMCO)
+                av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref short %d count %d\n",
+                       h->mmco[i].short_pic_num, h->short_ref_count);
             remove_short(h, frame_num, structure ^ PICT_FRAME);
             break;
         case MMCO_SHORT2LONG:
@@ -511,19 +611,19 @@ int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
                     remove_long(h, mmco[i].long_arg, 0);
 
                 remove_short_at_index(h, j);
-                h->long_ref[ mmco[i].long_arg ]= pic;
-                if (h->long_ref[ mmco[i].long_arg ]){
-                    h->long_ref[ mmco[i].long_arg ]->long_ref=1;
+                h->long_ref[ mmco[i].long_arg ] = pic;
+                if (h->long_ref[mmco[i].long_arg]) {
+                    h->long_ref[mmco[i].long_arg]->long_ref = 1;
                     h->long_ref_count++;
                 }
             break;
         case MMCO_LONG2UNUSED:
-            j = pic_num_extract(h, mmco[i].long_arg, &structure);
+            j   = pic_num_extract(h, mmco[i].long_arg, &structure);
             pic = h->long_ref[j];
             if (pic) {
                 remove_long(h, j, structure ^ PICT_FRAME);
-            } else if(s->avctx->debug&FF_DEBUG_MMCO)
-                av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: unref long failure\n");
+            } else if (h->avctx->debug & FF_DEBUG_MMCO)
+                av_log(h->avctx, AV_LOG_DEBUG, "mmco: unref long failure\n");
             break;
         case MMCO_LONG:
                     // Comment below left from previous code as it is an interresting note.
@@ -533,40 +633,37 @@ int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
                      * Report the problem and keep the pair where it is,
                      * and mark this field valid.
                      */
+            if (h->short_ref[0] == h->cur_pic_ptr)
+                remove_short_at_index(h, 0);
 
-            if (h->long_ref[mmco[i].long_arg] != s->current_picture_ptr) {
+            if (h->long_ref[mmco[i].long_arg] != h->cur_pic_ptr) {
                 remove_long(h, mmco[i].long_arg, 0);
 
-                h->long_ref[ mmco[i].long_arg ]= s->current_picture_ptr;
-                h->long_ref[ mmco[i].long_arg ]->long_ref=1;
+                h->long_ref[mmco[i].long_arg]           = h->cur_pic_ptr;
+                h->long_ref[mmco[i].long_arg]->long_ref = 1;
                 h->long_ref_count++;
             }
 
-            s->current_picture_ptr->reference |= s->picture_structure;
-            current_ref_assigned=1;
+            h->cur_pic_ptr->reference |= h->picture_structure;
+            current_ref_assigned = 1;
             break;
         case MMCO_SET_MAX_LONG:
             assert(mmco[i].long_arg <= 16);
             // just remove the long term which index is greater than new max
-            for(j = mmco[i].long_arg; j<16; j++){
+            for (j = mmco[i].long_arg; j < 16; j++) {
                 remove_long(h, j, 0);
             }
             break;
         case MMCO_RESET:
-            while(h->short_ref_count){
+            while (h->short_ref_count) {
                 remove_short(h, h->short_ref[0]->frame_num, 0);
             }
-            for(j = 0; j < 16; j++) {
+            for (j = 0; j < 16; j++) {
                 remove_long(h, j, 0);
             }
-            s->current_picture_ptr->poc=
-            s->current_picture_ptr->field_poc[0]=
-            s->current_picture_ptr->field_poc[1]=
-            h->poc_lsb=
-            h->poc_msb=
-            h->frame_num=
-            s->current_picture_ptr->frame_num= 0;
-            s->current_picture_ptr->mmco_reset=1;
+            h->frame_num  = h->cur_pic_ptr->frame_num = 0;
+            h->mmco_reset = 1;
+            h->cur_pic_ptr->mmco_reset = 1;
             break;
         default: assert(0);
         }
@@ -579,38 +676,44 @@ int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
          * in long_ref; trying to put it on the short list here is an
          * error in the encoded bit stream (ref: 7.4.3.3, NOTE 2 and 3).
          */
-        if (h->short_ref_count && h->short_ref[0] == s->current_picture_ptr) {
+        if (h->short_ref_count && h->short_ref[0] == h->cur_pic_ptr) {
             /* Just mark the second field valid */
-            s->current_picture_ptr->reference = PICT_FRAME;
-        } else if (s->current_picture_ptr->long_ref) {
-            av_log(h->s.avctx, AV_LOG_ERROR, "illegal short term reference "
-                                             "assignment for second field "
-                                             "in complementary field pair "
-                                             "(first field is long term)\n");
+            h->cur_pic_ptr->reference = PICT_FRAME;
+        } else if (h->cur_pic_ptr->long_ref) {
+            av_log(h->avctx, AV_LOG_ERROR, "illegal short term reference "
+                                           "assignment for second field "
+                                           "in complementary field pair "
+                                           "(first field is long term)\n");
+            err = AVERROR_INVALIDDATA;
         } else {
-            pic= remove_short(h, s->current_picture_ptr->frame_num, 0);
-            if(pic){
-                av_log(h->s.avctx, AV_LOG_ERROR, "illegal short term buffer state detected\n");
+            pic = remove_short(h, h->cur_pic_ptr->frame_num, 0);
+            if (pic) {
+                av_log(h->avctx, AV_LOG_ERROR, "illegal short term buffer state detected\n");
+                err = AVERROR_INVALIDDATA;
             }
 
-            if(h->short_ref_count)
-                memmove(&h->short_ref[1], &h->short_ref[0], h->short_ref_count*sizeof(Picture*));
+            if (h->short_ref_count)
+                memmove(&h->short_ref[1], &h->short_ref[0],
+                        h->short_ref_count * sizeof(H264Picture*));
 
-            h->short_ref[0]= s->current_picture_ptr;
+            h->short_ref[0] = h->cur_pic_ptr;
             h->short_ref_count++;
-            s->current_picture_ptr->reference |= s->picture_structure;
+            h->cur_pic_ptr->reference |= h->picture_structure;
         }
     }
 
-    if (h->long_ref_count + h->short_ref_count > h->sps.ref_frame_count){
+    if (h->long_ref_count + h->short_ref_count -
+        (h->short_ref[0] == h->cur_pic_ptr) > h->sps.ref_frame_count) {
 
         /* We have too many reference frames, probably due to corrupted
          * stream. Need to discard one frame. Prevents overrun of the
          * short_ref and long_ref buffers.
          */
-        av_log(h->s.avctx, AV_LOG_ERROR,
-               "number of reference frames exceeds max (probably "
-               "corrupt input), discarding one\n");
+        av_log(h->avctx, AV_LOG_ERROR,
+               "number of reference frames (%d+%d) exceeds max (%d; probably "
+               "corrupt input), discarding one\n",
+               h->long_ref_count, h->short_ref_count, h->sps.ref_frame_count);
+        err = AVERROR_INVALIDDATA;
 
         if (h->long_ref_count && !h->short_ref_count) {
             for (i = 0; i < 16; ++i)
@@ -627,68 +730,88 @@ int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
 
     print_short_term(h);
     print_long_term(h);
-    return 0;
+    return (h->avctx->err_recognition & AV_EF_EXPLODE) ? err : 0;
 }
 
-int ff_h264_decode_ref_pic_marking(H264Context *h, GetBitContext *gb){
-    MpegEncContext * const s = &h->s;
-    int i;
-
-    h->mmco_index= 0;
-    if(h->nal_unit_type == NAL_IDR_SLICE){ //FIXME fields
-        s->broken_link= get_bits1(gb) -1;
-        if(get_bits1(gb)){
-            h->mmco[0].opcode= MMCO_LONG;
-            h->mmco[0].long_arg= 0;
-            h->mmco_index= 1;
+int ff_h264_decode_ref_pic_marking(H264Context *h, GetBitContext *gb,
+                                   int first_slice)
+{
+    int i, ret;
+    MMCO mmco_temp[MAX_MMCO_COUNT], *mmco = first_slice ? h->mmco : mmco_temp;
+    int mmco_index = 0;
+
+    if (h->nal_unit_type == NAL_IDR_SLICE) { // FIXME fields
+        skip_bits1(gb); // broken_link
+        if (get_bits1(gb)) {
+            mmco[0].opcode   = MMCO_LONG;
+            mmco[0].long_arg = 0;
+            mmco_index       = 1;
         }
-    }else{
-        if(get_bits1(gb)){ // adaptive_ref_pic_marking_mode_flag
-            for(i= 0; i<MAX_MMCO_COUNT; i++) {
-                MMCOOpcode opcode= get_ue_golomb_31(gb);
-
-                h->mmco[i].opcode= opcode;
-                if(opcode==MMCO_SHORT2UNUSED || opcode==MMCO_SHORT2LONG){
-                    h->mmco[i].short_pic_num= (h->curr_pic_num - get_ue_golomb(gb) - 1) & (h->max_pic_num - 1);
-/*                    if(h->mmco[i].short_pic_num >= h->short_ref_count || h->short_ref[ h->mmco[i].short_pic_num ] == NULL){
-                        av_log(s->avctx, AV_LOG_ERROR, "illegal short ref in memory management control operation %d\n", mmco);
+    } else {
+        if (get_bits1(gb)) { // adaptive_ref_pic_marking_mode_flag
+            for (i = 0; i < MAX_MMCO_COUNT; i++) {
+                MMCOOpcode opcode = get_ue_golomb_31(gb);
+
+                mmco[i].opcode = opcode;
+                if (opcode == MMCO_SHORT2UNUSED || opcode == MMCO_SHORT2LONG) {
+                    mmco[i].short_pic_num =
+                        (h->curr_pic_num - get_ue_golomb(gb) - 1) &
+                            (h->max_pic_num - 1);
+#if 0
+                    if (mmco[i].short_pic_num >= h->short_ref_count ||
+                        !h->short_ref[mmco[i].short_pic_num]) {
+                        av_log(s->avctx, AV_LOG_ERROR,
+                               "illegal short ref in memory management control "
+                               "operation %d\n", mmco);
                         return -1;
-                    }*/
+                    }
+#endif
                 }
-                if(opcode==MMCO_SHORT2LONG || opcode==MMCO_LONG2UNUSED || opcode==MMCO_LONG || opcode==MMCO_SET_MAX_LONG){
-                    unsigned int long_arg= get_ue_golomb_31(gb);
-                    if(long_arg >= 32 || (long_arg >= 16 && !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE))){
-                        av_log(h->s.avctx, AV_LOG_ERROR, "illegal long ref in memory management control operation %d\n", opcode);
+                if (opcode == MMCO_SHORT2LONG || opcode == MMCO_LONG2UNUSED ||
+                    opcode == MMCO_LONG || opcode == MMCO_SET_MAX_LONG) {
+                    unsigned int long_arg = get_ue_golomb_31(gb);
+                    if (long_arg >= 32 ||
+                        (long_arg >= 16 && !(opcode == MMCO_SET_MAX_LONG &&
+                                             long_arg == 16) &&
+                         !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE(h)))) {
+                        av_log(h->avctx, AV_LOG_ERROR,
+                               "illegal long ref in memory management control "
+                               "operation %d\n", opcode);
                         return -1;
                     }
-                    h->mmco[i].long_arg= long_arg;
+                    mmco[i].long_arg = long_arg;
                 }
 
-                if(opcode > (unsigned)MMCO_LONG){
-                    av_log(h->s.avctx, AV_LOG_ERROR, "illegal memory management control operation %d\n", opcode);
+                if (opcode > (unsigned) MMCO_LONG) {
+                    av_log(h->avctx, AV_LOG_ERROR,
+                           "illegal memory management control operation %d\n",
+                           opcode);
                     return -1;
                 }
-                if(opcode == MMCO_END)
+                if (opcode == MMCO_END)
                     break;
             }
-            h->mmco_index= i;
-        }else{
-            assert(h->long_ref_count + h->short_ref_count <= h->sps.ref_frame_count);
-
-            if(h->short_ref_count && h->long_ref_count + h->short_ref_count == h->sps.ref_frame_count &&
-                    !(FIELD_PICTURE && !s->first_field && s->current_picture_ptr->reference)) {
-                h->mmco[0].opcode= MMCO_SHORT2UNUSED;
-                h->mmco[0].short_pic_num= h->short_ref[ h->short_ref_count - 1 ]->frame_num;
-                h->mmco_index= 1;
-                if (FIELD_PICTURE) {
-                    h->mmco[0].short_pic_num *= 2;
-                    h->mmco[1].opcode= MMCO_SHORT2UNUSED;
-                    h->mmco[1].short_pic_num= h->mmco[0].short_pic_num + 1;
-                    h->mmco_index= 2;
-                }
+            mmco_index = i;
+        } else {
+            if (first_slice) {
+                ret = ff_generate_sliding_window_mmcos(h, first_slice);
+                if (ret < 0 && h->avctx->err_recognition & AV_EF_EXPLODE)
+                    return ret;
             }
+            mmco_index = -1;
         }
     }
 
+    if (first_slice && mmco_index != -1) {
+        h->mmco_index = mmco_index;
+    } else if (!first_slice && mmco_index >= 0 &&
+               (mmco_index != h->mmco_index ||
+                check_opcodes(h->mmco, mmco_temp, mmco_index))) {
+        av_log(h->avctx, AV_LOG_ERROR,
+               "Inconsistent MMCO state between slices [%d, %d]\n",
+               mmco_index, h->mmco_index);
+        return AVERROR_INVALIDDATA;
+    }
+
     return 0;
 }