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ffmpeg / libavfilter / avfiltergraph.c @ 24de0edb

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/*
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 * filter graphs
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 * copyright (c) 2008 Vitor Sessak
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 * copyright (c) 2007 Bobby Bingham
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#include <ctype.h>
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#include <string.h>
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#include "avfilter.h"
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#include "avfiltergraph.h"
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AVFilterGraph *avfilter_graph_alloc(void)
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{
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    return av_mallocz(sizeof(AVFilterGraph));
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}
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void avfilter_graph_free(AVFilterGraph *graph)
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{
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    for(; graph->filter_count > 0; graph->filter_count --)
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        avfilter_free(graph->filters[graph->filter_count - 1]);
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    av_freep(&graph->scale_sws_opts);
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    av_freep(&graph->filters);
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}
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int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
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{
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    AVFilterContext **filters = av_realloc(graph->filters,
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                                           sizeof(AVFilterContext*) * (graph->filter_count+1));
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    if (!filters)
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        return AVERROR(ENOMEM);
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    graph->filters = filters;
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    graph->filters[graph->filter_count++] = filter;
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    return 0;
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}
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int avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
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{
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    AVFilterContext *filt;
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    int i, j;
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    for (i=0; i < graph->filter_count; i++) {
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        filt = graph->filters[i];
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        for (j = 0; j < filt->input_count; j++) {
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            if (!filt->inputs[j] || !filt->inputs[j]->src) {
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                av_log(log_ctx, AV_LOG_ERROR,
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                       "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
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                       filt->input_pads[j].name, filt->name, filt->filter->name);
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                return -1;
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            }
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        }
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        for (j = 0; j < filt->output_count; j++) {
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            if (!filt->outputs[j] || !filt->outputs[j]->dst) {
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                av_log(log_ctx, AV_LOG_ERROR,
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                       "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
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                       filt->output_pads[j].name, filt->name, filt->filter->name);
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                return -1;
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            }
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        }
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    }
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    return 0;
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}
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int avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)
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{
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    AVFilterContext *filt;
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    int i, ret;
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    for (i=0; i < graph->filter_count; i++) {
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        filt = graph->filters[i];
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        if (!filt->output_count) {
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            if ((ret = avfilter_config_links(filt)))
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                return ret;
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        }
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    }
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    return 0;
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}
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AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
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{
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    int i;
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    for(i = 0; i < graph->filter_count; i ++)
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        if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
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            return graph->filters[i];
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    return NULL;
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}
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static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)
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{
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    int i, j;
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    int scaler_count = 0;
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    char inst_name[30];
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    /* ask all the sub-filters for their supported media formats */
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    for(i = 0; i < graph->filter_count; i ++) {
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        if(graph->filters[i]->filter->query_formats)
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            graph->filters[i]->filter->query_formats(graph->filters[i]);
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        else
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            avfilter_default_query_formats(graph->filters[i]);
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    }
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    /* go through and merge as many format lists as possible */
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    for(i = 0; i < graph->filter_count; i ++) {
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        AVFilterContext *filter = graph->filters[i];
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        for(j = 0; j < filter->input_count; j ++) {
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            AVFilterLink *link = filter->inputs[j];
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            if(link && link->in_formats != link->out_formats) {
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                if(!avfilter_merge_formats(link->in_formats,
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                                           link->out_formats)) {
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                    AVFilterContext *scale;
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                    char scale_args[256];
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                    /* couldn't merge format lists. auto-insert scale filter */
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                    snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
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                             scaler_count++);
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                    avfilter_open(&scale, avfilter_get_by_name("scale"), inst_name);
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                    snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
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                    if(!scale || scale->filter->init(scale, scale_args, NULL) ||
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                                 avfilter_insert_filter(link, scale, 0, 0)) {
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                        avfilter_free(scale);
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                        return -1;
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                    }
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                    if (avfilter_graph_add_filter(graph, scale) < 0)
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                        return -1;
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                    scale->filter->query_formats(scale);
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                    if (((link = scale-> inputs[0]) &&
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                         !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
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                        ((link = scale->outputs[0]) &&
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                         !avfilter_merge_formats(link->in_formats, link->out_formats))) {
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                        av_log(log_ctx, AV_LOG_ERROR,
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                               "Impossible to convert between the formats supported by the filter "
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                               "'%s' and the filter '%s'\n", link->src->name, link->dst->name);
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                        return -1;
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                    }
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                }
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            }
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        }
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    }
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    return 0;
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}
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static void pick_format(AVFilterLink *link)
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{
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    if(!link || !link->in_formats)
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        return;
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    link->in_formats->format_count = 1;
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    link->format = link->in_formats->formats[0];
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    avfilter_formats_unref(&link->in_formats);
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    avfilter_formats_unref(&link->out_formats);
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}
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static void pick_formats(AVFilterGraph *graph)
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{
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    int i, j;
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    for(i = 0; i < graph->filter_count; i ++) {
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        AVFilterContext *filter = graph->filters[i];
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        for(j = 0; j < filter->input_count; j ++)
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            pick_format(filter->inputs[j]);
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        for(j = 0; j < filter->output_count; j ++)
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            pick_format(filter->outputs[j]);
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    }
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}
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int avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
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{
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    /* find supported formats from sub-filters, and merge along links */
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    if(query_formats(graph, log_ctx))
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        return -1;
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    /* Once everything is merged, it's possible that we'll still have
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     * multiple valid media format choices. We pick the first one. */
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    pick_formats(graph);
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    return 0;
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}
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int avfilter_graph_config(AVFilterGraph *graphctx, AVClass *log_ctx)
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{
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    int ret;
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    if ((ret = avfilter_graph_check_validity(graphctx, log_ctx)))
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        return ret;
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    if ((ret = avfilter_graph_config_formats(graphctx, log_ctx)))
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        return ret;
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    if ((ret = avfilter_graph_config_links(graphctx, log_ctx)))
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        return ret;
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    return 0;
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}