OpenShot Library | libopenshot 0.2.7
ImageReader.cpp
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1/**
2 * @file
3 * @brief Source file for ImageReader class
4 * @author Jonathan Thomas <jonathan@openshot.org>
5 *
6 * @ref License
7 */
8
9/* LICENSE
10 *
11 * Copyright (c) 2008-2019 OpenShot Studios, LLC
12 * <http://www.openshotstudios.com/>. This file is part of
13 * OpenShot Library (libopenshot), an open-source project dedicated to
14 * delivering high quality video editing and animation solutions to the
15 * world. For more information visit <http://www.openshot.org/>.
16 *
17 * OpenShot Library (libopenshot) is free software: you can redistribute it
18 * and/or modify it under the terms of the GNU Lesser General Public License
19 * as published by the Free Software Foundation, either version 3 of the
20 * License, or (at your option) any later version.
21 *
22 * OpenShot Library (libopenshot) is distributed in the hope that it will be
23 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
24 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
25 * GNU Lesser General Public License for more details.
26 *
27 * You should have received a copy of the GNU Lesser General Public License
28 * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
29 */
30
31// Require ImageMagick support
32#ifdef USE_IMAGEMAGICK
33
34#include "ImageReader.h"
35#include "Exceptions.h"
36
37using namespace openshot;
38
39ImageReader::ImageReader(const std::string& path, bool inspect_reader) : path(path), is_open(false)
40{
41 // Open and Close the reader, to populate its attributes (such as height, width, etc...)
42 if (inspect_reader) {
43 Open();
44 Close();
45 }
46}
47
48// Open image file
50{
51 // Open reader if not already open
52 if (!is_open)
53 {
54 // Attempt to open file
55 try
56 {
57 // load image
58 image = std::make_shared<Magick::Image>(path);
59
60 // Give image a transparent background color
61 image->backgroundColor(Magick::Color("none"));
62 MAGICK_IMAGE_ALPHA(image, true);
63 }
64 catch (const Magick::Exception& e) {
65 // raise exception
66 throw InvalidFile("File could not be opened.", path);
67 }
68
69 // Update image properties
70 info.has_audio = false;
71 info.has_video = true;
73 info.file_size = image->fileSize();
74 info.vcodec = image->format();
75 info.width = image->size().width();
76 info.height = image->size().height();
79 info.duration = 60 * 60 * 1; // 1 hour duration
80 info.fps.num = 30;
81 info.fps.den = 1;
85
86 // Calculate the DAR (display aspect ratio)
88
89 // Reduce size fraction
90 size.Reduce();
91
92 // Set the ratio based on the reduced fraction
95
96 // Mark as "open"
97 is_open = true;
98 }
99}
100
101// Close image file
103{
104 // Close all objects, if reader is 'open'
105 if (is_open)
106 {
107 // Mark as "closed"
108 is_open = false;
109
110 // Delete the image
111 image.reset();
112 }
113}
114
115// Get an openshot::Frame object for a specific frame number of this reader.
116std::shared_ptr<Frame> ImageReader::GetFrame(int64_t requested_frame)
117{
118 // Check for open reader (or throw exception)
119 if (!is_open)
120 throw ReaderClosed("The FFmpegReader is closed. Call Open() before calling this method.", path);
121
122 // Create or get frame object
123 auto image_frame = std::make_shared<Frame>(
124 requested_frame, image->size().width(), image->size().height(),
125 "#000000", 0, 2);
126
127 // Add Image data to frame
128 image_frame->AddMagickImage(image);
129
130 // return frame object
131 return image_frame;
132}
133
134// Generate JSON string of this object
135std::string ImageReader::Json() const {
136
137 // Return formatted string
138 return JsonValue().toStyledString();
139}
140
141// Generate Json::Value for this object
142Json::Value ImageReader::JsonValue() const {
143
144 // Create root json object
145 Json::Value root = ReaderBase::JsonValue(); // get parent properties
146 root["type"] = "ImageReader";
147 root["path"] = path;
148
149 // return JsonValue
150 return root;
151}
152
153// Load JSON string into this object
154void ImageReader::SetJson(const std::string value) {
155
156 // Parse JSON string into JSON objects
157 try
158 {
159 const Json::Value root = openshot::stringToJson(value);
160 // Set all values that match
161 SetJsonValue(root);
162 }
163 catch (const std::exception& e)
164 {
165 // Error parsing JSON (or missing keys)
166 throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
167 }
168}
169
170// Load Json::Value into this object
171void ImageReader::SetJsonValue(const Json::Value root) {
172
173 // Set parent data
175
176 // Set data from Json (if key is found)
177 if (!root["path"].isNull())
178 path = root["path"].asString();
179
180 // Re-Open path, and re-init everything (if needed)
181 if (is_open)
182 {
183 Close();
184 Open();
185 }
186}
187
188#endif //USE_IMAGEMAGICK
Header file for all Exception classes.
Header file for ImageReader class.
#define MAGICK_IMAGE_ALPHA(im, a)
This class represents a fraction.
Definition: Fraction.h:48
int num
Numerator for the fraction.
Definition: Fraction.h:50
double ToDouble() const
Return this fraction as a double (i.e. 1/2 = 0.5)
Definition: Fraction.cpp:59
void Reduce()
Reduce this fraction (i.e. 640/480 = 4/3)
Definition: Fraction.cpp:84
int den
Denominator for the fraction.
Definition: Fraction.h:51
void Open() override
Open File - which is called by the constructor automatically.
Definition: ImageReader.cpp:49
std::shared_ptr< Frame > GetFrame(int64_t requested_frame) override
void SetJson(const std::string value) override
Load JSON string into this object.
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Json::Value JsonValue() const override
Generate Json::Value for this object.
std::string Json() const override
Generate JSON string of this object.
void Close() override
Close File.
Exception for files that can not be found or opened.
Definition: Exceptions.h:174
Exception for invalid JSON.
Definition: Exceptions.h:206
openshot::ReaderInfo info
Information about the current media file.
Definition: ReaderBase.h:111
virtual void SetJsonValue(const Json::Value root)=0
Load Json::Value into this object.
Definition: ReaderBase.cpp:171
virtual Json::Value JsonValue() const =0
Generate Json::Value for this object.
Definition: ReaderBase.cpp:116
Exception when a reader is closed, and a frame is requested.
Definition: Exceptions.h:338
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:47
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:34
bool has_single_image
Determines if this file only contains a single image.
Definition: ReaderBase.h:64
float duration
Length of time (in seconds)
Definition: ReaderBase.h:65
int width
The width of the video (in pixesl)
Definition: ReaderBase.h:68
openshot::Fraction fps
Frames per second, as a fraction (i.e. 24/1 = 24 fps)
Definition: ReaderBase.h:70
openshot::Fraction display_ratio
The ratio of width to height of the video stream (i.e. 640x480 has a ratio of 4/3)
Definition: ReaderBase.h:73
int height
The height of the video (in pixels)
Definition: ReaderBase.h:67
int64_t video_length
The number of frames in the video stream.
Definition: ReaderBase.h:75
std::string vcodec
The name of the video codec used to encode / decode the video stream.
Definition: ReaderBase.h:74
openshot::Fraction pixel_ratio
The pixel ratio of the video stream as a fraction (i.e. some pixels are not square)
Definition: ReaderBase.h:72
bool has_video
Determines if this file has a video stream.
Definition: ReaderBase.h:62
bool has_audio
Determines if this file has an audio stream.
Definition: ReaderBase.h:63
openshot::Fraction video_timebase
The video timebase determines how long each frame stays on the screen.
Definition: ReaderBase.h:77
int64_t file_size
Size of file (in bytes)
Definition: ReaderBase.h:66