Add the graph2dot tools and document it.

Also link avfiltergraph.o and graphparser.o against libavfilter, as it
uses them.

Originally committed as revision 22063 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Stefano Sabatini 2010-02-25 19:55:01 +00:00
parent 9c16add67b
commit 11ab237e31
3 changed files with 193 additions and 0 deletions

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@ -71,6 +71,34 @@ There exist so-called @var{source filters} that do not have a video
input, and we expect in the future some @var{sink filters} that will
not have video output.
@chapter graph2dot
The @file{graph2dot} program included in the FFmpeg @file{tools}
directory can be used to parse a filter graph description and issue a
corresponding textual representation in the dot language.
Invoke the command:
@example
graph2dot -h
@end example
to see how to use @file{graph2dot}.
You can then pass the dot description to the @file{dot} program (from
the graphviz suite of programs) and obtain a graphical representation
of the filter graph.
For example the sequence of commands:
@example
echo @var{GRAPH_DESCRIPTION} | \
tools/graph2dot -o graph.tmp && \
dot -Tpng graph.tmp -o graph.png && \
display graph.png
@end example
can be used to create and display an image representing the graph
described by the @var{GRAPH_DESCRIPTION} string.
@chapter Available video filters
When you configure your FFmpeg build, you can disable any of the

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@ -8,8 +8,10 @@ HEADERS = avfilter.h
OBJS = allfilters.o \
avfilter.o \
avfiltergraph.o \
defaults.o \
formats.o \
graphparser.o \
parseutils.o \
OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o

163
tools/graph2dot.c Normal file
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@ -0,0 +1,163 @@
/*
* Copyright (c) 2008-2010 Stefano Sabatini
*
* 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 <unistd.h> /* getopt */
#undef HAVE_AV_CONFIG_H
#include "libavutil/pixdesc.h"
#include "libavfilter/graphparser.h"
static void usage(void)
{
printf("Convert a libavfilter graph to a dot file\n");
printf("Usage: graph2dot [OPTIONS]\n");
printf("\n"
"Options:\n"
"-i INFILE set INFILE as input file, stdin if omitted\n"
"-o OUTFILE set OUTFILE as output file, stdout if omitted\n"
"-h print this help\n");
}
struct line {
char data[256];
struct line *next;
};
static void print_digraph(FILE *outfile, AVFilterGraph *graph)
{
int i, j;
fprintf(outfile, "digraph G {\n");
fprintf(outfile, "node [shape=box]\n");
fprintf(outfile, "rankdir=LR\n");
for (i = 0; i < graph->filter_count; i++) {
char filter_ctx_label[128];
const AVFilterContext *filter_ctx = graph->filters[i];
snprintf(filter_ctx_label, sizeof(filter_ctx_label), "%s (%s)",
filter_ctx->name,
filter_ctx->filter->name);
for (j = 0; j < filter_ctx->output_count; j++) {
AVFilterLink *link = filter_ctx->outputs[j];
if (link) {
char dst_filter_ctx_label[128];
const AVFilterContext *dst_filter_ctx = link->dst;
snprintf(dst_filter_ctx_label, sizeof(dst_filter_ctx_label), "%s (%s)",
dst_filter_ctx->name,
dst_filter_ctx->filter->name);
fprintf(outfile, "\"%s\" -> \"%s\"", filter_ctx_label, dst_filter_ctx_label);
fprintf(outfile, " [ label= \"fmt:%s w:%d h:%d\"];\n",
av_pix_fmt_descriptors[link->format].name, link->w, link->h);
}
}
}
fprintf(outfile, "}\n");
}
int main(int argc, char **argv)
{
const char *outfilename = NULL;
const char *infilename = NULL;
FILE *outfile = NULL;
FILE *infile = NULL;
char *graph_string = NULL;
AVFilterGraph *graph = av_mallocz(sizeof(AVFilterGraph));
char c;
av_log_set_level(AV_LOG_DEBUG);
while ((c = getopt(argc, argv, "hi:o:")) != -1) {
switch(c) {
case 'h':
usage();
return 0;
case 'i':
infilename = optarg;
break;
case 'o':
outfilename = optarg;
break;
case '?':
return 1;
}
}
if (!infilename || !strcmp(infilename, "-"))
infilename = "/dev/stdin";
infile = fopen(infilename, "r");
if (!infile) {
fprintf(stderr, "Impossible to open input file '%s': %s\n", infilename, strerror(errno));
return 1;
}
if (!outfilename || !strcmp(outfilename, "-"))
outfilename = "/dev/stdout";
outfile = fopen(outfilename, "w");
if (!outfile) {
fprintf(stderr, "Impossible to open output file '%s': %s\n", outfilename, strerror(errno));
return 1;
}
/* read from infile and put it in a buffer */
{
unsigned int count = 0;
struct line *line, *last_line, *first_line;
char *p;
last_line = first_line = av_malloc(sizeof(struct line));
while (fgets(last_line->data, sizeof(last_line->data), infile)) {
struct line *new_line = av_malloc(sizeof(struct line));
count += strlen(last_line->data);
last_line->next = new_line;
last_line = new_line;
}
last_line->next = NULL;
graph_string = av_malloc(count + 1);
p = graph_string;
for (line = first_line; line->next; line = line->next) {
unsigned int l = strlen(line->data);
memcpy(p, line->data, l);
p += l;
}
*p = '\0';
}
avfilter_register_all();
if (avfilter_graph_parse(graph, graph_string, NULL, NULL, NULL) < 0) {
fprintf(stderr, "Impossible to parse the graph description\n");
return 1;
}
if (avfilter_graph_check_validity(graph, NULL) ||
avfilter_graph_config_formats(graph, NULL) ||
avfilter_graph_config_links (graph, NULL))
return 1;
print_digraph(outfile, graph);
fflush(outfile);
return 0;
}