ffmpeg/libavfilter/avfiltergraph.c

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/*
* 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 "avfilter.h"
#include "avfiltergraph.h"
void avfilter_graph_destroy(AVFilterGraph *graph)
{
for(; graph->filter_count > 0; graph->filter_count --)
avfilter_destroy(graph->filters[graph->filter_count - 1]);
av_freep(&graph->scale_sws_opts);
av_freep(&graph->filters);
}
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_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 -1;
}
}
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 -1;
}
}
}
return 0;
}
int 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;
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++);
avfilter_open(&scale, avfilter_get_by_name("scale"), inst_name);
snprintf(scale_args, sizeof(scale_args), "0:0:%s", graph->scale_sws_opts);
if(!scale || scale->filter->init(scale, scale_args, NULL) ||
avfilter_insert_filter(link, scale, 0, 0)) {
avfilter_destroy(scale);
return -1;
}
if (avfilter_graph_add_filter(graph, scale) < 0)
return -1;
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 -1;
}
}
}
}
}
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);
}
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 avfilter_graph_config_formats(AVFilterGraph *graph, AVClass *log_ctx)
{
/* find supported formats from sub-filters, and merge along links */
if(query_formats(graph, log_ctx))
return -1;
/* 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, AVClass *log_ctx)
{
int ret;
if ((ret = avfilter_graph_check_validity(graphctx, log_ctx)))
return ret;
if ((ret = avfilter_graph_config_formats(graphctx, log_ctx)))
return ret;
if ((ret = avfilter_graph_config_links(graphctx, log_ctx)))
return ret;
return 0;
}