示例#1
0
int ff_h264_execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count)
{
    int i, av_uninit(j);
    int pps_count;
    int current_ref_assigned = 0, err = 0;
    Picture *av_uninit(pic);

    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++) {
        int av_uninit(structure), av_uninit(frame_num);
        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) {
            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->avctx, h->short_ref_count ? AV_LOG_ERROR : AV_LOG_DEBUG, "mmco: unref short failure\n");
                    err = AVERROR_INVALIDDATA;
                }
                continue;
            }
        }

        switch (mmco[i].opcode) {
        case MMCO_SHORT2UNUSED:
            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:
                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 (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.
                    /* 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->short_ref[0] == h->cur_pic_ptr) {
                av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to short and long at the same time\n");
                remove_short_at_index(h, 0);
            }

            if (h->long_ref[mmco[i].long_arg] != h->cur_pic_ptr) {
                if (h->cur_pic_ptr->long_ref) {
                    for(j=0; j<16; j++) {
                        if(h->long_ref[j] == h->cur_pic_ptr) {
                            remove_long(h, j, 0);
                            av_log(h->avctx, AV_LOG_ERROR, "mmco: cannot assign current picture to 2 long term references\n");
                        }
                    }
                }
                av_assert0(!h->cur_pic_ptr->long_ref);
                remove_long(h, mmco[i].long_arg, 0);

                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++;
            }

            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++) {
                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);
            }
            h->frame_num  = h->cur_pic_ptr->frame_num = 0;
            h->mmco_reset = 1;
            h->cur_pic_ptr->mmco_reset = 1;
            for (j = 0; j < MAX_DELAYED_PIC_COUNT; j++)
                h->last_pocs[j] = INT_MIN;
            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] == h->cur_pic_ptr) {
            /* Just mark the second field valid */
            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, 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*));

            h->short_ref[0] = h->cur_pic_ptr;
            h->short_ref_count++;
            h->cur_pic_ptr->reference |= h->picture_structure;
        }
    }

    if (h->long_ref_count + h->short_ref_count > FFMAX(h->sps.ref_frame_count, 1)) {

        /* 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->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)
                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);

    pps_count = 0;
    for (i = 0; i < FF_ARRAY_ELEMS(h->pps_buffers); i++)
        pps_count += !!h->pps_buffers[i];

    if (   err >= 0
        && h->long_ref_count==0
        && (h->short_ref_count<=2 || h->pps.ref_count[0] <= 1 && h->pps.ref_count[1] <= 1 && pps_count == 1)
        && h->pps.ref_count[0]<=2 + (h->picture_structure != PICT_FRAME)
        && h->cur_pic_ptr->f.pict_type == AV_PICTURE_TYPE_I){
        h->cur_pic_ptr->recovered |= 1;
        if(!h->avctx->has_b_frames)
            h->frame_recovered |= FRAME_RECOVERED_SEI;
    }

    return (h->avctx->err_recognition & AV_EF_EXPLODE) ? err : 0;
}
示例#2
0
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++) {
        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(&h->gb)) {
            int pred = h->curr_pic_num;

            for (index = 0; ; index++) {
                unsigned int reordering_of_pic_nums_idc = get_ue_golomb_31(&h->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->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(&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 -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(&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 -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->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--) {
                            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->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].f.buf[0]
                || (!FIELD_PICTURE(h) && (h->ref_list[list][index].reference&3) != 3)) {
                int i;
                av_log(h->avctx, AV_LOG_ERROR, "Missing reference picture, default is %d\n", h->default_ref_list[list][0].poc);
                for (i = 0; i < FF_ARRAY_ELEMS(h->last_pocs); i++)
                    h->last_pocs[i] = INT_MIN;
                if (h->default_ref_list[list][0].f.buf[0]
                    && !(!FIELD_PICTURE(h) && (h->default_ref_list[list][0].reference&3) != 3))
                    COPY_PICTURE(&h->ref_list[list][index], &h->default_ref_list[list][0]);
                else
                    return -1;
            }
            av_assert0(av_buffer_get_ref_count(h->ref_list[list][index].f.buf[0]) > 0);
        }
    }

    return 0;
}
示例#3
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 > FFMAX(h->sps.ref_frame_count, 1)){

        /* 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 (%d+%d) exceeds max (%d; probably "
               "corrupt input), discarding one\n",
               h->long_ref_count, h->short_ref_count, h->sps.ref_frame_count);

        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;
}
示例#4
0
文件: h264_refs.c 项目: kkirby/FFmpeg
int ff_h264_decode_ref_pic_list_reordering(H264Context *h, H264SliceContext *sl)
{
    int list, index, pic_structure;

    print_short_term(h);
    print_long_term(h);

    h264_initialise_ref_list(h, sl);

    for (list = 0; list < sl->list_count; list++) {
        if (get_bits1(&sl->gb)) {    // ref_pic_list_modification_flag_l[01]
            int pred = h->curr_pic_num;

            for (index = 0; ; index++) {
                unsigned int modification_of_pic_nums_idc = get_ue_golomb_31(&sl->gb);
                unsigned int pic_id;
                int i;
                H264Picture *ref = NULL;

                if (modification_of_pic_nums_idc == 3)
                    break;

                if (index >= sl->ref_count[list]) {
                    av_log(h->avctx, AV_LOG_ERROR, "reference count overflow\n");
                    return -1;
                }

                switch (modification_of_pic_nums_idc) {
                case 0:
                case 1: {
                    const unsigned int abs_diff_pic_num = get_ue_golomb_long(&sl->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 (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(&sl->gb); // long_term_pic_idx

                    long_idx = pic_num_extract(h, pic_id, &pic_structure);

                    if (long_idx > 31U) {
                        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) && !mismatches_ref(h, ref)) {
                        ref->pic_id = pic_id;
                        assert(ref->long_ref);
                        i = 0;
                    } else {
                        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(&sl->ref_list[list][index], 0, sizeof(sl->ref_list[0][0])); // FIXME
                } else {
                    for (i = index; i + 1 < sl->ref_count[list]; i++) {
                        if (sl->ref_list[list][i].parent &&
                            ref->long_ref == sl->ref_list[list][i].parent->long_ref &&
                            ref->pic_id   == sl->ref_list[list][i].pic_id)
                            break;
                    }
                    for (; i > index; i--) {
                        sl->ref_list[list][i] = sl->ref_list[list][i - 1];
                    }
                    ref_from_h264pic(&sl->ref_list[list][index], ref);
                    if (FIELD_PICTURE(h)) {
                        pic_as_field(&sl->ref_list[list][index], pic_structure);
                    }
                }
            }
        }
    }
    for (list = 0; list < sl->list_count; list++) {
        for (index = 0; index < sl->ref_count[list]; index++) {
            if (   !sl->ref_list[list][index].parent
                || (!FIELD_PICTURE(h) && (sl->ref_list[list][index].reference&3) != 3)) {
                int i;
                av_log(h->avctx, AV_LOG_ERROR, "Missing reference picture, default is %d\n", h->default_ref[list].poc);
                for (i = 0; i < FF_ARRAY_ELEMS(h->last_pocs); i++)
                    h->last_pocs[i] = INT_MIN;
                if (h->default_ref[list].parent
                    && !(!FIELD_PICTURE(h) && (h->default_ref[list].reference&3) != 3))
                    sl->ref_list[list][index] = h->default_ref[list];
                else
                    return -1;
            }
            av_assert0(av_buffer_get_ref_count(sl->ref_list[list][index].parent->f->buf[0]) > 0);
        }
    }

    return 0;
}
示例#5
0
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;
}