2 Copyright (C) 2012-2021 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/>.
22 /** @file src/lib/filter_graph.cc
23 * @brief A graph of FFmpeg filters.
27 #include "filter_graph.h"
29 #include "exceptions.h"
31 #include "compose.hpp"
33 #include <libavfilter/buffersrc.h>
34 #include <libavfilter/buffersink.h>
35 #include <libavformat/avio.h>
48 using std::shared_ptr;
54 FilterGraph::setup(vector<Filter> const& filters)
56 auto const filters_string = Filter::ffmpeg_string (filters);
57 if (filters.empty()) {
63 _frame = av_frame_alloc ();
65 _graph = avfilter_graph_alloc();
67 throw DecodeError (N_("could not create filter graph."));
70 auto const buffer_src = avfilter_get_by_name (src_name().c_str());
72 throw DecodeError (N_("could not find buffer src filter"));
75 auto const buffer_sink = avfilter_get_by_name (sink_name().c_str());
77 throw DecodeError (N_("Could not create buffer sink filter"));
80 if (avfilter_graph_create_filter (&_buffer_src_context, buffer_src, N_("in"), src_parameters().c_str(), 0, _graph) < 0) {
81 throw DecodeError (N_("could not create buffer source"));
84 if (avfilter_graph_create_filter (&_buffer_sink_context, buffer_sink, N_("out"), nullptr, nullptr, _graph) < 0) {
85 throw DecodeError (N_("could not create buffer sink."));
88 set_parameters (_buffer_sink_context);
90 auto outputs = avfilter_inout_alloc ();
91 outputs->name = av_strdup(N_("in"));
92 outputs->filter_ctx = _buffer_src_context;
96 auto inputs = avfilter_inout_alloc ();
97 inputs->name = av_strdup(N_("out"));
98 inputs->filter_ctx = _buffer_sink_context;
102 if (avfilter_graph_parse (_graph, filters_string.c_str(), inputs, outputs, 0) < 0) {
103 throw DecodeError (N_("could not set up filter graph."));
106 int e = avfilter_graph_config (_graph, 0);
108 throw DecodeError (String::compose(N_("could not configure filter graph (%1)"), e));
113 FilterGraph::~FilterGraph ()
116 av_frame_free (&_frame);
120 avfilter_graph_free (&_graph);
126 FilterGraph::get (string name)
128 return avfilter_graph_get_filter (_graph, name.c_str());