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_decoder.h"
40 using std::stringstream;
43 using boost::shared_ptr;
44 using boost::weak_ptr;
47 /** Construct a FilterGraph for the settings in a piece of content.
48 * @param content Content.
49 * @param s Size of the images to process.
50 * @param p Pixel format of the images to process.
52 FilterGraph::FilterGraph (shared_ptr<const FFmpegContent> content, libdcp::Size s, AVPixelFormat p)
53 : _buffer_src_context (0)
54 , _buffer_sink_context (0)
58 _frame = av_frame_alloc ();
60 string filters = Filter::ffmpeg_strings (content->filters()).first;
61 if (!filters.empty ()) {
65 Crop crop = content->crop ();
66 libdcp::Size cropped_size = _size;
67 cropped_size.width -= crop.left + crop.right;
68 cropped_size.height -= crop.top + crop.bottom;
69 filters += crop_string (Position (crop.left, crop.top), cropped_size);
71 AVFilterGraph* graph = avfilter_graph_alloc();
73 throw DecodeError (N_("could not create filter graph."));
76 AVFilter* buffer_src = avfilter_get_by_name(N_("buffer"));
77 if (buffer_src == 0) {
78 throw DecodeError (N_("could not find buffer src filter"));
81 AVFilter* buffer_sink = avfilter_get_by_name(N_("buffersink"));
82 if (buffer_sink == 0) {
83 throw DecodeError (N_("Could not create buffer sink filter"));
87 a << "video_size=" << _size.width << "x" << _size.height << ":"
88 << "pix_fmt=" << _pixel_format << ":"
90 << "pixel_aspect=0/1";
94 if ((r = avfilter_graph_create_filter (&_buffer_src_context, buffer_src, "in", a.str().c_str(), 0, graph)) < 0) {
95 throw DecodeError (N_("could not create buffer source"));
98 AVBufferSinkParams* sink_params = av_buffersink_params_alloc ();
99 PixelFormat* pixel_fmts = new PixelFormat[2];
100 pixel_fmts[0] = _pixel_format;
101 pixel_fmts[1] = PIX_FMT_NONE;
102 sink_params->pixel_fmts = pixel_fmts;
104 if (avfilter_graph_create_filter (&_buffer_sink_context, buffer_sink, N_("out"), 0, sink_params, graph) < 0) {
105 throw DecodeError (N_("could not create buffer sink."));
108 av_free (sink_params);
110 AVFilterInOut* outputs = avfilter_inout_alloc ();
111 outputs->name = av_strdup(N_("in"));
112 outputs->filter_ctx = _buffer_src_context;
113 outputs->pad_idx = 0;
116 AVFilterInOut* inputs = avfilter_inout_alloc ();
117 inputs->name = av_strdup(N_("out"));
118 inputs->filter_ctx = _buffer_sink_context;
122 if (avfilter_graph_parse (graph, filters.c_str(), &inputs, &outputs, 0) < 0) {
123 throw DecodeError (N_("could not set up filter graph."));
126 if (avfilter_graph_config (graph, 0) < 0) {
127 throw DecodeError (N_("could not configure filter graph."));
130 /* XXX: leaking `inputs' / `outputs' ? */
133 FilterGraph::~FilterGraph ()
135 av_frame_free (&_frame);
138 /** Take an AVFrame and process it using our configured filters, returning a
139 * set of Images. Caller handles memory management of the input frame.
141 list<shared_ptr<Image> >
142 FilterGraph::process (AVFrame* frame)
144 list<shared_ptr<Image> > images;
146 if (av_buffersrc_write_frame (_buffer_src_context, frame) < 0) {
147 throw DecodeError (N_("could not push buffer into filter chain."));
151 if (av_buffersink_get_frame (_buffer_sink_context, _frame) < 0) {
155 images.push_back (shared_ptr<Image> (new SimpleImage (_frame)));
161 /** @param s Image size.
162 * @param p Pixel format.
163 * @return true if this chain can process images with `s' and `p', otherwise false.
166 FilterGraph::can_process (libdcp::Size s, AVPixelFormat p) const
168 return (_size == s && _pixel_format == p);