Split all the reference picture handling off h264.c.

Originally committed as revision 21172 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 700 insertions, 0 deletions

diff --git a/libavcodec/h264_refs.c b/libavcodec/h264_refs.c
new file mode 100644
index 0000000000..fa9afd1c8b
--- /dev/null
+++ b/libavcodec/h264_refs.c
@@ -0,0 +1,700 @@
+/*
+ * 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.
+ *
+ * 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_refs.c
+ * H.264 / AVC / MPEG4 part10  reference picture handling.
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+#include "internal.h"
+#include "dsputil.h"
+#include "avcodec.h"
+#include "h264.h"
+#include "golomb.h"
+
+//#undef NDEBUG
+#include <assert.h>
+
+
+static void pic_as_field(Picture *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->poc= pic->field_poc[parity == PICT_BOTTOM_FIELD];
+}
+
+static int split_field_copy(Picture *dest, Picture *src,
+                            int parity, int id_add){
+    int match = !!(src->reference & parity);
+
+    if (match) {
+        *dest = *src;
+        if(parity != PICT_FRAME){
+            pic_as_field(dest, parity);
+            dest->pic_id *= 2;
+            dest->pic_id += id_add;
+        }
+    }
+
+    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;
+
+    while(i[0]<len || i[1]<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))))
+            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[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);
+        }
+    }
+
+    return index;
+}
+
+static int add_sorted(Picture **sorted, Picture **src, int len, int limit, int dir){
+    int i, best_poc;
+    int out_i= 0;
+
+    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];
+            }
+        }
+        if(best_poc == (dir ? INT_MIN : INT_MAX))
+            break;
+        limit= sorted[out_i++]->poc - dir;
+    }
+    return out_i;
+}
+
+int ff_h264_fill_default_ref_list(H264Context *h){
+    MpegEncContext * const s = &h->s;
+    int i, len;
+
+    if(h->slice_type_nos==FF_B_TYPE){
+        Picture *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 ];
+        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;
+        }
+
+        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]);
+        }
+    }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));
+    }
+#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]);
+    }
+    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]);
+        }
+    }
+#endif
+    return 0;
+}
+
+static void print_short_term(H264Context *h);
+static void print_long_term(H264Context *h);
+
+/**
+ * Extract structure information about the picture described by pic_num in
+ * the current decoding context (frame or field). Note that pic_num is
+ * picture number without wrapping (so, 0<=pic_num<max_pic_num).
+ * @param pic_num picture number for which to extract structure information
+ * @param structure one of PICT_XXX describing structure of picture
+ *                      with pic_num
+ * @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){
+        if (!(pic_num & 1))
+            /* opposite field */
+            *structure ^= PICT_FRAME;
+        pic_num >>= 1;
+    }
+
+    return pic_num;
+}
+
+int ff_h264_decode_ref_pic_list_reordering(H264Context *h){
+    MpegEncContext * const s = &h->s;
+    int list, index, pic_structure;
+
+    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]);
+
+        if(get_bits1(&s->gb)){
+            int pred= h->curr_pic_num;
+
+            for(index=0; ; index++){
+                unsigned int reordering_of_pic_nums_idc= get_ue_golomb_31(&s->gb);
+                unsigned int pic_id;
+                int i;
+                Picture *ref = NULL;
+
+                if(reordering_of_pic_nums_idc==3)
+                    break;
+
+                if(index >= h->ref_count[list]){
+                    av_log(h->s.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;
+                        }
+                    }
+
+                    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
+                    } 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);
+                        }
+                    }
+                }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];
+                else
+                    return -1;
+            }
+        }
+    }
+
+    return 0;
+}
+
+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;
+            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[1].reference = PICT_BOTTOM_FIELD;
+            field[1].poc= field[1].field_poc[1];
+
+            h->luma_weight[list][16+2*i] = h->luma_weight[list][16+2*i+1] = h->luma_weight[list][i];
+            h->luma_offset[list][16+2*i] = h->luma_offset[list][16+2*i+1] = h->luma_offset[list][i];
+            for(j=0; j<2; j++){
+                h->chroma_weight[list][16+2*i][j] = h->chroma_weight[list][16+2*i+1][j] = h->chroma_weight[list][i][j];
+                h->chroma_offset[list][16+2*i][j] = h->chroma_offset[list][16+2*i+1][j] = h->chroma_offset[list][i][j];
+            }
+        }
+    }
+    for(j=0; j<h->ref_count[1]; j++){
+        for(i=0; i<h->ref_count[0]; i++)
+            h->implicit_weight[j][16+2*i] = h->implicit_weight[j][16+2*i+1] = h->implicit_weight[j][i];
+        memcpy(h->implicit_weight[16+2*j],   h->implicit_weight[j], sizeof(*h->implicit_weight));
+        memcpy(h->implicit_weight[16+2*j+1], h->implicit_weight[j], sizeof(*h->implicit_weight));
+    }
+}
+
+/**
+ * Mark a picture as no longer needed for reference. The refmask
+ * argument allows unreferencing of individual fields or the whole frame.
+ * If the picture becomes entirely unreferenced, but is being held for
+ * display purposes, it is marked as such.
+ * @param refmask mask of fields to unreference; the mask is bitwise
+ *                anded with the reference marking of pic
+ * @return non-zero if pic becomes entirely unreferenced (except possibly
+ *         for display purposes) zero if one of the fields remains in
+ *         reference
+ */
+static inline int unreference_pic(H264Context *h, Picture *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;
+                break;
+            }
+        return 1;
+    }
+}
+
+/**
+ * Find a Picture 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;
+    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) {
+            *idx = i;
+            return pic;
+        }
+    }
+    return NULL;
+}
+
+/**
+ * Remove a picture from the short term reference list by its index in
+ * that list.  This does no checking on the provided index; it is assumed
+ * 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){
+    assert(i >= 0 && i < h->short_ref_count);
+    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*));
+}
+
+/**
+ *
+ * @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;
+    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);
+
+    pic = find_short(h, frame_num, &i);
+    if (pic){
+        if(unreference_pic(h, pic, ref_mask))
+        remove_short_at_index(h, i);
+    }
+
+    return pic;
+}
+
+/**
+ * Remove a picture from the long term reference list by its index in
+ * 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;
+
+    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_count--;
+        }
+    }
+
+    return pic;
+}
+
+void ff_h264_remove_all_refs(H264Context *h){
+    int i;
+
+    for(i=0; i<16; i++){
+        remove_long(h, i, 0);
+    }
+    assert(h->long_ref_count==0);
+
+    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_count=0;
+}
+
+/**
+ * print short term list
+ */
+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]);
+        }
+    }
+}
+
+/**
+ * print long term list
+ */
+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 (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]);
+            }
+        }
+    }
+}
+
+int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
+    MpegEncContext * const s = &h->s;
+    int i, av_uninit(j);
+    int current_ref_assigned=0;
+    Picture *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");
+
+    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(   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");
+                continue;
+            }
+        }
+
+        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);
+            remove_short(h, frame_num, structure ^ PICT_FRAME);
+            break;
+        case MMCO_SHORT2LONG:
+                if (h->long_ref[mmco[i].long_arg] != pic)
+                    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_count++;
+                }
+            break;
+        case MMCO_LONG2UNUSED:
+            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");
+            break;
+        case MMCO_LONG:
+                    // Comment below left from previous code as it is an interresting note.
+                    /* First field in pair is in short term list or
+                     * at a different long term index.
+                     * This is not allowed; see 7.4.3.3, notes 2 and 3.
+                     * Report the problem and keep the pair where it is,
+                     * and mark this field valid.
+                     */
+
+            if (h->long_ref[mmco[i].long_arg] != s->current_picture_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_count++;
+            }
+
+            s->current_picture_ptr->reference |= s->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++){
+                remove_long(h, j, 0);
+            }
+            break;
+        case MMCO_RESET:
+            while(h->short_ref_count){
+                remove_short(h, h->short_ref[0]->frame_num, 0);
+            }
+            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;
+            break;
+        default: assert(0);
+        }
+    }
+
+    if (!current_ref_assigned) {
+        /* Second field of complementary field pair; the first field of
+         * which is already referenced. If short referenced, it
+         * should be first entry in short_ref. If not, it must exist
+         * 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) {
+            /* 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");
+        } 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");
+            }
+
+            if(h->short_ref_count)
+                memmove(&h->short_ref[1], &h->short_ref[0], h->short_ref_count*sizeof(Picture*));
+
+            h->short_ref[0]= s->current_picture_ptr;
+            h->short_ref_count++;
+            s->current_picture_ptr->reference |= s->picture_structure;
+        }
+    }
+
+    if (h->long_ref_count + h->short_ref_count > 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");
+
+        if (h->long_ref_count && !h->short_ref_count) {
+            for (i = 0; i < 16; ++i)
+                if (h->long_ref[i])
+                    break;
+
+            assert(i < 16);
+            remove_long(h, i, 0);
+        } else {
+            pic = h->short_ref[h->short_ref_count - 1];
+            remove_short(h, pic->frame_num, 0);
+        }
+    }
+
+    print_short_term(h);
+    print_long_term(h);
+    return 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;
+        }
+    }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);
+                        return -1;
+                    }*/
+                }
+                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);
+                        return -1;
+                    }
+                    h->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);
+                    return -1;
+                }
+                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;
+                }
+            }
+        }
+    }
+
+    return 0;
+}