/*

  * filter graphs

  * Copyright (c) 2008 Vitor Sessak
  * Copyright (c) 2007 Bobby Bingham

  *
  * 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
  */
 

 #include <ctype.h>
 #include <string.h>
 

 #include "libavutil/avstring.h"

 #include "avfilter.h"
 #include "avfiltergraph.h"

 #include "internal.h"

 AVFilterGraph *avfilter_graph_alloc(void)
 {
     return av_mallocz(sizeof(AVFilterGraph));
 }
 

 void avfilter_graph_free(AVFilterGraph **graph)

 {

     if (!*graph)

         return;

     for (; (*graph)->filter_count > 0; (*graph)->filter_count--)
         avfilter_free((*graph)->filters[(*graph)->filter_count - 1]);
     av_freep(&(*graph)->scale_sws_opts);
     av_freep(&(*graph)->filters);
     av_freep(graph);

 }
 

 int avfilter_graph_add_filter(AVFilterGraph *graph, AVFilterContext *filter)

 {

     AVFilterContext **filters = av_realloc(graph->filters,
                                            sizeof(AVFilterContext*) * (graph->filter_count+1));
     if (!filters)

         return AVERROR(ENOMEM);

     graph->filters = filters;
     graph->filters[graph->filter_count++] = filter;

 
     return 0;

 }
 

 int avfilter_graph_create_filter(AVFilterContext **filt_ctx, AVFilter *filt,
                                  const char *name, const char *args, void *opaque,
                                  AVFilterGraph *graph_ctx)
 {
     int ret;
 
     if ((ret = avfilter_open(filt_ctx, filt, name)) < 0)
         goto fail;
     if ((ret = avfilter_init_filter(*filt_ctx, args, opaque)) < 0)
         goto fail;
     if ((ret = avfilter_graph_add_filter(graph_ctx, *filt_ctx)) < 0)
         goto fail;
     return 0;
 
 fail:
     if (*filt_ctx)
         avfilter_free(*filt_ctx);
     *filt_ctx = NULL;
     return ret;
 }
 

 int ff_avfilter_graph_check_validity(AVFilterGraph *graph, AVClass *log_ctx)

 {
     AVFilterContext *filt;
     int i, j;
 

     for (i = 0; i < graph->filter_count; i++) {

         filt = graph->filters[i];
 
         for (j = 0; j < filt->input_count; j++) {
             if (!filt->inputs[j] || !filt->inputs[j]->src) {
                 av_log(log_ctx, AV_LOG_ERROR,
                        "Input pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any source\n",
                        filt->input_pads[j].name, filt->name, filt->filter->name);

                 return AVERROR(EINVAL);

             }
         }
 
         for (j = 0; j < filt->output_count; j++) {
             if (!filt->outputs[j] || !filt->outputs[j]->dst) {
                 av_log(log_ctx, AV_LOG_ERROR,
                        "Output pad \"%s\" for the filter \"%s\" of type \"%s\" not connected to any destination\n",
                        filt->output_pads[j].name, filt->name, filt->filter->name);

                 return AVERROR(EINVAL);

             }
         }
     }
 
     return 0;
 }
 

 int ff_avfilter_graph_config_links(AVFilterGraph *graph, AVClass *log_ctx)

 {
     AVFilterContext *filt;
     int i, ret;
 
     for (i=0; i < graph->filter_count; i++) {
         filt = graph->filters[i];
 
         if (!filt->output_count) {
             if ((ret = avfilter_config_links(filt)))
                 return ret;
         }
     }
 
     return 0;
 }
 

 AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, char *name)

 {
     int i;
 

     for (i = 0; i < graph->filter_count; i++)
         if (graph->filters[i]->name && !strcmp(name, graph->filters[i]->name))

             return graph->filters[i];
 
     return NULL;
 }
 

 static int query_formats(AVFilterGraph *graph, AVClass *log_ctx)

 {

     int i, j, ret;

     int scaler_count = 0;
     char inst_name[30];

     /* ask all the sub-filters for their supported media formats */

     for (i = 0; i < graph->filter_count; i++) {
         if (graph->filters[i]->filter->query_formats)

             graph->filters[i]->filter->query_formats(graph->filters[i]);
         else
             avfilter_default_query_formats(graph->filters[i]);
     }
 
     /* go through and merge as many format lists as possible */

     for (i = 0; i < graph->filter_count; i++) {

         AVFilterContext *filter = graph->filters[i];
 

         for (j = 0; j < filter->input_count; j++) {

             AVFilterLink *link = filter->inputs[j];

             if (link && link->in_formats != link->out_formats) {
                 if (!avfilter_merge_formats(link->in_formats,
                                             link->out_formats)) {

                     AVFilterContext *scale;

                     char scale_args[256];

                     /* couldn't merge format lists. auto-insert scale filter */

                     snprintf(inst_name, sizeof(inst_name), "auto-inserted scaler %d",

                              scaler_count++);

                     av_strlcpy(scale_args, "0:0", sizeof(scale_args));
                     if (graph->scale_sws_opts) {
                         av_strlcat(scale_args, ":", sizeof(scale_args));
                         av_strlcat(scale_args, graph->scale_sws_opts, sizeof(scale_args));
                     }

                     if ((ret = avfilter_graph_create_filter(&scale, avfilter_get_by_name("scale"),
                                                             inst_name, scale_args, NULL, graph)) < 0)
                         return ret;
                     if ((ret = avfilter_insert_filter(link, scale, 0, 0)) < 0)
                         return ret;

                     scale->filter->query_formats(scale);

                     if (((link = scale-> inputs[0]) &&
                          !avfilter_merge_formats(link->in_formats, link->out_formats)) ||
                         ((link = scale->outputs[0]) &&
                          !avfilter_merge_formats(link->in_formats, link->out_formats))) {
                         av_log(log_ctx, AV_LOG_ERROR,
                                "Impossible to convert between the formats supported by the filter "
                                "'%s' and the filter '%s'\n", link->src->name, link->dst->name);

                         return AVERROR(EINVAL);

                     }

                 }
             }
         }
     }
 
     return 0;
 }
 
 static void pick_format(AVFilterLink *link)
 {

     if (!link || !link->in_formats)

         return;
 
     link->in_formats->format_count = 1;
     link->format = link->in_formats->formats[0];
     avfilter_formats_unref(&link->in_formats);
     avfilter_formats_unref(&link->out_formats);

 
     if (link->type == AVMEDIA_TYPE_AUDIO) {
         link->in_chlayouts->format_count = 1;
         link->channel_layout = link->in_chlayouts->formats[0];
         avfilter_formats_unref(&link->in_chlayouts);
         avfilter_formats_unref(&link->out_chlayouts);
     }
 

 }
 

 static void pick_formats(AVFilterGraph *graph)

 {
     int i, j;
 

     for (i = 0; i < graph->filter_count; i++) {

         AVFilterContext *filter = graph->filters[i];
 

         for (j = 0; j < filter->input_count; j++)

             pick_format(filter->inputs[j]);

         for (j = 0; j < filter->output_count; j++)

             pick_format(filter->outputs[j]);
     }
 }
 

 int ff_avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)

 {

     int ret;
 

     /* find supported formats from sub-filters, and merge along links */

     if ((ret = query_formats(graph, log_ctx)) < 0)
         return ret;

 
     /* Once everything is merged, it's possible that we'll still have

      * multiple valid media format choices. We pick the first one. */

     pick_formats(graph);
 
     return 0;
 }
 

 int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx)

 {
     int ret;
 

     if ((ret = ff_avfilter_graph_check_validity(graphctx, log_ctx)))

         return ret;

     if ((ret = ff_avfilter_graph_config_formats(graphctx, log_ctx)))

         return ret;

     if ((ret = ff_avfilter_graph_config_links(graphctx, log_ctx)))

         return ret;
 
     return 0;
 }