2 Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
4 This file is part of DCP-o-matic.
6 DCP-o-matic is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 DCP-o-matic is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with DCP-o-matic. If not, see <http://www.gnu.org/licenses/>.
21 /** @file src/lib/filter_graph.cc
22 * @brief A graph of FFmpeg filters.
25 #include "filter_graph.h"
27 #include "exceptions.h"
29 #include "compose.hpp"
31 #include <libavfilter/avfiltergraph.h>
32 #include <libavfilter/buffersrc.h>
33 #include <libavfilter/buffersink.h>
34 #include <libavformat/avio.h>
46 using boost::shared_ptr;
47 using boost::weak_ptr;
50 /** Construct a FilterGraph for the settings in a piece of content */
51 FilterGraph::FilterGraph ()
54 , _buffer_src_context (0)
55 , _buffer_sink_context (0)
62 FilterGraph::setup (vector<Filter const *> filters)
64 string const filters_string = Filter::ffmpeg_string (filters);
65 if (filters.empty ()) {
70 _frame = av_frame_alloc ();
72 _graph = avfilter_graph_alloc();
74 throw DecodeError (N_("could not create filter graph."));
77 AVFilter const * buffer_src = avfilter_get_by_name (src_name().c_str());
79 throw DecodeError (N_("could not find buffer src filter"));
82 AVFilter const * buffer_sink = avfilter_get_by_name (sink_name().c_str());
84 throw DecodeError (N_("Could not create buffer sink filter"));
87 if (avfilter_graph_create_filter (&_buffer_src_context, buffer_src, N_("in"), src_parameters().c_str(), 0, _graph) < 0) {
88 throw DecodeError (N_("could not create buffer source"));
91 void* sink_params = sink_parameters ();
93 if (avfilter_graph_create_filter (&_buffer_sink_context, buffer_sink, N_("out"), 0, sink_params, _graph) < 0) {
94 throw DecodeError (N_("could not create buffer sink."));
97 av_free (sink_params);
99 AVFilterInOut* outputs = avfilter_inout_alloc ();
100 outputs->name = av_strdup(N_("in"));
101 outputs->filter_ctx = _buffer_src_context;
102 outputs->pad_idx = 0;
105 AVFilterInOut* inputs = avfilter_inout_alloc ();
106 inputs->name = av_strdup(N_("out"));
107 inputs->filter_ctx = _buffer_sink_context;
111 if (avfilter_graph_parse (_graph, filters_string.c_str(), inputs, outputs, 0) < 0) {
112 throw DecodeError (N_("could not set up filter graph."));
115 if (avfilter_graph_config (_graph, 0) < 0) {
116 throw DecodeError (N_("could not configure filter graph."));
120 FilterGraph::~FilterGraph ()
123 av_frame_free (&_frame);
127 avfilter_graph_free (&_graph);
132 FilterGraph::get (string name)
134 return avfilter_graph_get_filter (_graph, name.c_str ());