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"
37 #include "ffmpeg_decoder.h"
41 using std::stringstream;
44 using boost::shared_ptr;
47 /** Construct a FilterGraph for the settings in a film.
49 * @param decoder Decoder that we are using.
50 * @param s Size of the images to process.
51 * @param p Pixel format of the images to process.
53 FilterGraph::FilterGraph (shared_ptr<Film> film, FFmpegDecoder* decoder, libdcp::Size s, AVPixelFormat p)
54 : _buffer_src_context (0)
55 , _buffer_sink_context (0)
59 string filters = Filter::ffmpeg_strings (film->filters()).first;
60 if (!filters.empty ()) {
64 filters += crop_string (Position (film->crop().left, film->crop().top), film->cropped_size (decoder->native_size()));
66 AVFilterGraph* graph = avfilter_graph_alloc();
68 throw DecodeError (N_("could not create filter graph."));
71 AVFilter* buffer_src = avfilter_get_by_name(N_("buffer"));
72 if (buffer_src == 0) {
73 throw DecodeError (N_("could not find buffer src filter"));
76 AVFilter* buffer_sink = avfilter_get_by_name(N_("buffersink"));
77 if (buffer_sink == 0) {
78 throw DecodeError (N_("Could not create buffer sink filter"));
82 a << _size.width << N_(":")
83 << _size.height << N_(":")
84 << _pixel_format << N_(":")
85 << decoder->time_base_numerator() << N_(":")
86 << decoder->time_base_denominator() << N_(":")
87 << decoder->sample_aspect_ratio_numerator() << N_(":")
88 << decoder->sample_aspect_ratio_denominator();
92 if ((r = avfilter_graph_create_filter (&_buffer_src_context, buffer_src, N_("in"), a.str().c_str(), 0, graph)) < 0) {
93 throw DecodeError (N_("could not create buffer source"));
96 AVBufferSinkParams* sink_params = av_buffersink_params_alloc ();
97 PixelFormat* pixel_fmts = new PixelFormat[2];
98 pixel_fmts[0] = _pixel_format;
99 pixel_fmts[1] = PIX_FMT_NONE;
100 sink_params->pixel_fmts = pixel_fmts;
102 if (avfilter_graph_create_filter (&_buffer_sink_context, buffer_sink, N_("out"), 0, sink_params, graph) < 0) {
103 throw DecodeError (N_("could not create buffer sink."));
106 AVFilterInOut* outputs = avfilter_inout_alloc ();
107 outputs->name = av_strdup(N_("in"));
108 outputs->filter_ctx = _buffer_src_context;
109 outputs->pad_idx = 0;
112 AVFilterInOut* inputs = avfilter_inout_alloc ();
113 inputs->name = av_strdup(N_("out"));
114 inputs->filter_ctx = _buffer_sink_context;
118 if (avfilter_graph_parse (graph, filters.c_str(), &inputs, &outputs, 0) < 0) {
119 throw DecodeError (N_("could not set up filter graph."));
122 if (avfilter_graph_config (graph, 0) < 0) {
123 throw DecodeError (N_("could not configure filter graph."));
126 /* XXX: leaking `inputs' / `outputs' ? */
129 /** Take an AVFrame and process it using our configured filters, returning a
132 list<shared_ptr<Image> >
133 FilterGraph::process (AVFrame const * frame)
135 list<shared_ptr<Image> > images;
138 if (av_buffersrc_write_frame (_buffer_src_context, frame) < 0) {
139 throw DecodeError (N_("could not push buffer into filter chain."));
142 while (av_buffersink_read (_buffer_sink_context, 0)) {
143 AVFilterBufferRef* filter_buffer;
144 if (av_buffersink_get_buffer_ref (_buffer_sink_context, &filter_buffer, 0) < 0) {
149 /* This takes ownership of filter_buffer */
150 images.push_back (shared_ptr<Image> (new FilterBufferImage ((PixelFormat) frame->format, filter_buffer)));
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);