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libavfilter/avfiltergraph.c

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00001 /*
00002  * filter graphs
00003  * copyright (c) 2008 Vitor Sessak
00004  * copyright (c) 2007 Bobby Bingham
00005  *
00006  * This file is part of FFmpeg.
00007  *
00008  * FFmpeg is free software; you can redistribute it and/or
00009  * modify it under the terms of the GNU Lesser General Public
00010  * License as published by the Free Software Foundation; either
00011  * version 2.1 of the License, or (at your option) any later version.
00012  *
00013  * FFmpeg is distributed in the hope that it will be useful,
00014  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00015  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00016  * Lesser General Public License for more details.
00017  *
00018  * You should have received a copy of the GNU Lesser General Public
00019  * License along with FFmpeg; if not, write to the Free Software
00020  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00021  */
00022 
00023 #include <ctype.h>
00024 #include <string.h>
00025 
00026 #include "avfilter.h"
00027 #include "avfiltergraph.h"
00028 
00029 void avfilter_graph_destroy(AVFilterGraph *graph)
00030 {
00031     for(; graph->filter_count > 0; graph->filter_count --)
00032         avfilter_destroy(graph->filters[graph->filter_count - 1]);
00033     av_freep(&graph->scale_sws_opts);
00034     av_freep(&graph->filters);
00035 }
00036 
00037 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)
00038 {
00039     graph->filters = av_realloc(graph->filters,
00040                                 sizeof(AVFilterContext*) * ++graph->filter_count);
00041 
00042     if (!graph->filters)
00043         return -1;
00044 
00045     graph->filters[graph->filter_count - 1] = filter;
00046 
00047     return 0;
00048 }
00049 
00050 int avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)
00051 {
00052     AVFilterContext *filt;
00053     int i, j;
00054 
00055     for (i=0; i < graph->filter_count; i++) {
00056         filt = graph->filters[i];
00057 
00058         for (j = 0; j < filt->input_count; j++) {
00059             if (!filt->inputs[j] || !filt->inputs[j]->src) {
00060                 av_log(log_ctx, AV_LOG_ERROR,
00061                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
00062                        filt->input_pads[j].name, filt->name, filt->filter->name);
00063                 return -1;
00064             }
00065         }
00066 
00067         for (j = 0; j < filt->output_count; j++) {
00068             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
00069                 av_log(log_ctx, AV_LOG_ERROR,
00070                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
00071                        filt->output_pads[j].name, filt->name, filt->filter->name);
00072                 return -1;
00073             }
00074         }
00075     }
00076 
00077     return 0;
00078 }
00079 
00080 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)
00081 {
00082     int i;
00083 
00084     for(i = 0; i < graph->filter_count; i ++)
00085         if(graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))
00086             return graph->filters[i];
00087 
00088     return NULL;
00089 }
00090 
00091 static int query_formats(AVFilterGraph *graph)
00092 {
00093     int i, j;
00094     int scaler_count = 0;
00095     char inst_name[30];
00096 
00097     /* ask all the sub-filters for their supported colorspaces */
00098     for(i = 0; i < graph->filter_count; i ++) {
00099         if(graph->filters[i]->filter->query_formats)
00100             graph->filters[i]->filter->query_formats(graph->filters[i]);
00101         else
00102             avfilter_default_query_formats(graph->filters[i]);
00103     }
00104 
00105     /* go through and merge as many format lists as possible */
00106     for(i = 0; i < graph->filter_count; i ++) {
00107         AVFilterContext *filter = graph->filters[i];
00108 
00109         for(j = 0; j < filter->input_count; j ++) {
00110             AVFilterLink *link = filter->inputs[j];
00111             if(link && link->in_formats != link->out_formats) {
00112                 if(!avfilter_merge_formats(link->in_formats,
00113                                            link->out_formats)) {
00114                     AVFilterContext *scale;
00115                     char scale_args[256];
00116                     /* couldn't merge format lists. auto-insert scale filter */
00117                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",
00118                              scaler_count);
00119                     scale =
00120                         avfilter_open(avfilter_get_by_name("scale"),inst_name);
00121 
00122                     snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
00123                     if(!scale || scale->filter->init(scale, scale_args, NULL) ||
00124                                  avfilter_insert_filter(link, scale, 0, 0)) {
00125                         avfilter_destroy(scale);
00126                         return -1;
00127                     }
00128 
00129                     if (avfilter_graph_add_filter(graph, scale) < 0)
00130                         return -1;
00131 
00132                     scale->filter->query_formats(scale);
00133                     if(!avfilter_merge_formats(scale-> inputs[0]->in_formats,
00134                                                scale-> inputs[0]->out_formats)||
00135                        !avfilter_merge_formats(scale->outputs[0]->in_formats,
00136                                                scale->outputs[0]->out_formats))
00137                         return -1;
00138                 }
00139             }
00140         }
00141     }
00142 
00143     return 0;
00144 }
00145 
00146 static void pick_format(AVFilterLink *link)
00147 {
00148     if(!link || !link->in_formats)
00149         return;
00150 
00151     link->in_formats->format_count = 1;
00152     link->format = link->in_formats->formats[0];
00153 
00154     avfilter_formats_unref(&link->in_formats);
00155     avfilter_formats_unref(&link->out_formats);
00156 }
00157 
00158 static void pick_formats(AVFilterGraph *graph)
00159 {
00160     int i, j;
00161 
00162     for(i = 0; i < graph->filter_count; i ++) {
00163         AVFilterContext *filter = graph->filters[i];
00164 
00165         for(j = 0; j < filter->input_count; j ++)
00166             pick_format(filter->inputs[j]);
00167         for(j = 0; j < filter->output_count; j ++)
00168             pick_format(filter->outputs[j]);
00169     }
00170 }
00171 
00172 int avfilter_graph_config_formats(AVFilterGraph *graph)
00173 {
00174     /* find supported formats from sub-filters, and merge along links */
00175     if(query_formats(graph))
00176         return -1;
00177 
00178     /* Once everything is merged, it's possible that we'll still have
00179      * multiple valid colorspace choices. We pick the first one. */
00180     pick_formats(graph);
00181 
00182     return 0;
00183 }
00184 

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