2 Copyright (C) 2012 Carl Hetherington <cth@carlh.net>
4 This program is free software; you can redistribute it and/or modify
5 it under the terms of the GNU General Public License as published by
6 the Free Software Foundation; either version 2 of the License, or
7 (at your option) any later version.
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 /** @file src/lib/filter_graph.cc
21 * @brief A graph of FFmpeg filters.
25 #include <libavfilter/avfiltergraph.h>
26 #include <libavfilter/buffersrc.h>
27 #include <libavfilter/avcodec.h>
28 #include <libavfilter/buffersink.h>
29 #include <libavformat/avio.h>
32 #include "filter_graph.h"
34 #include "exceptions.h"
36 #include "ffmpeg_content.h"
40 using std::stringstream;
46 using boost::shared_ptr;
47 using boost::weak_ptr;
50 /** Construct a FilterGraph for the settings in a piece of content.
51 * @param content Content.
52 * @param s Size of the images to process.
53 * @param p Pixel format of the images to process.
55 FilterGraph::FilterGraph (shared_ptr<const FFmpegContent> content, libdcp::Size s, AVPixelFormat p)
56 : _buffer_src_context (0)
57 , _buffer_sink_context (0)
61 _frame = av_frame_alloc ();
63 string filters = Filter::ffmpeg_strings (content->filters()).first;
64 if (filters.empty ()) {
68 AVFilterGraph* graph = avfilter_graph_alloc();
70 throw DecodeError (N_("could not create filter graph."));
73 AVFilter* buffer_src = avfilter_get_by_name(N_("buffer"));
74 if (buffer_src == 0) {
75 throw DecodeError (N_("could not find buffer src filter"));
78 AVFilter* buffer_sink = avfilter_get_by_name(N_("buffersink"));
79 if (buffer_sink == 0) {
80 throw DecodeError (N_("Could not create buffer sink filter"));
84 a << "video_size=" << _size.width << "x" << _size.height << ":"
85 << "pix_fmt=" << _pixel_format << ":"
87 << "pixel_aspect=1/1";
89 if (avfilter_graph_create_filter (&_buffer_src_context, buffer_src, "in", a.str().c_str(), 0, graph) < 0) {
90 throw DecodeError (N_("could not create buffer source"));
93 AVBufferSinkParams* sink_params = av_buffersink_params_alloc ();
94 PixelFormat* pixel_fmts = new PixelFormat[2];
95 pixel_fmts[0] = _pixel_format;
96 pixel_fmts[1] = PIX_FMT_NONE;
97 sink_params->pixel_fmts = pixel_fmts;
99 if (avfilter_graph_create_filter (&_buffer_sink_context, buffer_sink, N_("out"), 0, sink_params, graph) < 0) {
100 throw DecodeError (N_("could not create buffer sink."));
103 av_free (sink_params);
105 AVFilterInOut* outputs = avfilter_inout_alloc ();
106 outputs->name = av_strdup(N_("in"));
107 outputs->filter_ctx = _buffer_src_context;
108 outputs->pad_idx = 0;
111 AVFilterInOut* inputs = avfilter_inout_alloc ();
112 inputs->name = av_strdup(N_("out"));
113 inputs->filter_ctx = _buffer_sink_context;
117 if (avfilter_graph_parse (graph, filters.c_str(), &inputs, &outputs, 0) < 0) {
118 throw DecodeError (N_("could not set up filter graph."));
121 if (avfilter_graph_config (graph, 0) < 0) {
122 throw DecodeError (N_("could not configure filter graph."));
125 /* XXX: leaking `inputs' / `outputs' ? */
128 FilterGraph::~FilterGraph ()
130 av_frame_free (&_frame);
133 /** Take an AVFrame and process it using our configured filters, returning a
134 * set of Images. Caller handles memory management of the input frame.
136 list<pair<shared_ptr<Image>, int64_t> >
137 FilterGraph::process (AVFrame* frame)
139 list<pair<shared_ptr<Image>, int64_t> > images;
141 if (av_buffersrc_write_frame (_buffer_src_context, frame) < 0) {
142 throw DecodeError (N_("could not push buffer into filter chain."));
146 if (av_buffersink_get_frame (_buffer_sink_context, _frame) < 0) {
150 images.push_back (make_pair (shared_ptr<Image> (new Image (_frame)), av_frame_get_best_effort_timestamp (_frame)));
151 av_frame_unref (_frame);
157 /** @param s Image size.
158 * @param p Pixel format.
159 * @return true if this chain can process images with `s' and `p', otherwise false.
162 FilterGraph::can_process (libdcp::Size s, AVPixelFormat p) const
164 return (_size == s && _pixel_format == p);