2 Copyright (C) 2014 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 #ifndef DCPOMATIC_IMAGE_PROXY_H
22 #define DCPOMATIC_IMAGE_PROXY_H
24 /** @file src/lib/image_proxy.h
25 * @brief ImageProxy and subclasses.
29 #include <libavutil/pixfmt.h>
31 #include <dcp/types.h>
32 #include <boost/optional.hpp>
33 #include <boost/utility.hpp>
47 * @brief A class which holds an Image, and can produce it on request.
49 * This is so that decoding of source images can be postponed until
50 * the encoder thread, where multi-threading is happening, instead
51 * of happening in a single-threaded decoder.
53 * For example, large TIFFs are slow to decode, so this class will keep
54 * the TIFF data compressed until the decompressed image is needed.
55 * At this point, the class decodes the TIFF to an Image.
57 class ImageProxy : public boost::noncopyable
60 virtual ~ImageProxy () {}
63 Result (std::shared_ptr<Image> image_, int log2_scaling_)
65 , log2_scaling (log2_scaling_)
69 Result (std::shared_ptr<Image> image_, int log2_scaling_, bool error_)
71 , log2_scaling (log2_scaling_)
75 /** Image (which will be aligned) */
76 std::shared_ptr<Image> image;
77 /** log2 of any scaling down that has already been applied to the image;
78 * e.g. if the image is already half the size of the original, this value
82 /** true if there was an error during image decoding, otherwise false */
86 /** @param log Log to write to, or 0.
87 * @param size Size that the returned image will be scaled to, in case this
88 * can be used as an optimisation.
90 virtual Result image (
91 boost::optional<dcp::Size> size = boost::optional<dcp::Size> ()
94 virtual void add_metadata (xmlpp::Node *) const = 0;
95 virtual void write_to_socket (std::shared_ptr<Socket>) const = 0;
96 /** @return true if our image is definitely the same as another, false if it is probably not */
97 virtual bool same (std::shared_ptr<const ImageProxy>) const = 0;
98 /** Do any useful work that would speed up a subsequent call to ::image().
99 * This method may be called in a different thread to image().
100 * @return log2 of any scaling down that will be applied to the image.
102 virtual int prepare (boost::optional<dcp::Size> = boost::optional<dcp::Size>()) const { return 0; }
103 virtual size_t memory_used () const = 0;
106 std::shared_ptr<ImageProxy> image_proxy_factory (std::shared_ptr<cxml::Node> xml, std::shared_ptr<Socket> socket);