OpenShot Library | libopenshot 0.2.7
ImageWriter.cpp
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1/**
2 * @file
3 * @brief Source file for ImageWriter class
4 * @author Jonathan Thomas <jonathan@openshot.org>, Fabrice Bellard
5 *
6 * @ref License
7 */
8
9/* LICENSE
10 *
11 * Copyright (c) 2008-2019 OpenShot Studios, LLC, Fabrice Bellard
12 * (http://www.openshotstudios.com). This file is part of
13 * OpenShot Library (http://www.openshot.org), an open-source project
14 * dedicated to delivering high quality video editing and animation solutions
15 * to the world.
16 *
17 * This file is originally based on the Libavformat API example, and then modified
18 * by the libopenshot project.
19 *
20 * OpenShot Library (libopenshot) is free software: you can redistribute it
21 * and/or modify it under the terms of the GNU Lesser General Public License
22 * as published by the Free Software Foundation, either version 3 of the
23 * License, or (at your option) any later version.
24 *
25 * OpenShot Library (libopenshot) is distributed in the hope that it will be
26 * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
28 * GNU Lesser General Public License for more details.
29 *
30 * You should have received a copy of the GNU Lesser General Public License
31 * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
32 */
33
34//Require ImageMagick support
35#ifdef USE_IMAGEMAGICK
36
37#include "ImageWriter.h"
38#include "Exceptions.h"
39
40using namespace openshot;
41
42ImageWriter::ImageWriter(std::string path) :
43 path(path), cache_size(8), write_video_count(0), image_quality(75), number_of_loops(1),
44 combine_frames(true), is_open(false)
45{
46 // Disable audio & video (so they can be independently enabled)
47 info.has_audio = false;
48 info.has_video = true;
49}
50
51// Set video export options
52void ImageWriter::SetVideoOptions(std::string format, Fraction fps, int width, int height,
53 int quality, int loops, bool combine)
54{
55 // Set frames per second (if provided)
56 info.fps.num = fps.num;
57 info.fps.den = fps.den;
58
59 // Set image magic properties
60 image_quality = quality;
61 number_of_loops = loops;
62 combine_frames = combine;
63 info.vcodec = format;
64
65 // Set the timebase (inverse of fps)
68
69 if (width >= 1)
70 info.width = width;
71 if (height >= 1)
72 info.height = height;
73
74 info.video_bit_rate = quality;
75
76 // Calculate the DAR (display aspect ratio)
78
79 // Reduce size fraction
80 size.Reduce();
81
82 // Set the ratio based on the reduced fraction
85
86 ZmqLogger::Instance()->AppendDebugMethod("ImageWriter::SetVideoOptions (" + format + ")", "width", width, "height", height, "size.num", size.num, "size.den", size.den, "fps.num", fps.num, "fps.den", fps.den);
87}
88
89// Open the writer
91{
92 is_open = true;
93}
94
95// Add a frame to the queue waiting to be encoded.
96void ImageWriter::WriteFrame(std::shared_ptr<Frame> frame)
97{
98 // Check for open reader (or throw exception)
99 if (!is_open)
100 throw WriterClosed("The ImageWriter is closed. Call Open() before calling this method.", path);
101
102
103 // Copy and resize image
104 std::shared_ptr<Magick::Image> frame_image = frame->GetMagickImage();
105 frame_image->magick( info.vcodec );
106 frame_image->backgroundColor(Magick::Color("none"));
107 MAGICK_IMAGE_ALPHA(frame_image, true);
108 frame_image->quality(image_quality);
109 frame_image->animationDelay(info.video_timebase.ToFloat() * 100);
110 frame_image->animationIterations(number_of_loops);
111
112 // Calculate correct DAR (display aspect ratio)
113 int new_width = info.width;
114 int new_height = info.height * frame->GetPixelRatio().Reciprocal().ToDouble();
115
116 // Resize image
117 Magick::Geometry new_size(new_width, new_height);
118 new_size.aspect(true);
119 frame_image->resize(new_size);
120
121
122 // Put resized frame in vector (waiting to be written)
123 frames.push_back(*frame_image.get());
124
125 // Keep track of the last frame added
126 last_frame = frame;
127}
128
129// Write a block of frames from a reader
130void ImageWriter::WriteFrame(ReaderBase* reader, int64_t start, int64_t length)
131{
132 ZmqLogger::Instance()->AppendDebugMethod("ImageWriter::WriteFrame (from Reader)", "start", start, "length", length);
133
134 // Loop through each frame (and encoded it)
135 for (int64_t number = start; number <= length; number++)
136 {
137 // Get the frame
138 std::shared_ptr<Frame> f = reader->GetFrame(number);
139
140 // Encode frame
141 WriteFrame(f);
142 }
143}
144
145// Close the writer and encode/output final image to the disk.
147{
148 // Write frame's image to file
149 Magick::writeImages(frames.begin(), frames.end(), path, combine_frames);
150
151 // Clear frames vector
152 frames.clear();
153
154 // Reset frame counters
155 write_video_count = 0;
156
157 // Close writer
158 is_open = false;
159
160 ZmqLogger::Instance()->AppendDebugMethod("ImageWriter::Close");
161}
162
163#endif //USE_IMAGEMAGICK
Header file for all Exception classes.
Header file for ImageWriter 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
float ToFloat()
Return this fraction as a float (i.e. 1/2 = 0.5)
Definition: Fraction.cpp:54
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 WriteFrame(ReaderBase *reader, int64_t start, int64_t length)
Write a block of frames from a reader.
void Close()
Close the writer and encode/output final image to the disk. This is a requirement of ImageMagick,...
void SetVideoOptions(std::string format, Fraction fps, int width, int height, int quality, int loops, bool combine)
Set the video export options.
Definition: ImageWriter.cpp:52
void WriteFrame(std::shared_ptr< Frame > frame)
Add a frame to the stack waiting to be encoded.
Definition: ImageWriter.cpp:96
void Open()
Open writer.
Definition: ImageWriter.cpp:90
This abstract class is the base class, used by all readers in libopenshot.
Definition: ReaderBase.h:98
virtual std::shared_ptr< openshot::Frame > GetFrame(int64_t number)=0
WriterInfo info
Information about the current media file.
Definition: WriterBase.h:94
Exception when too many seek attempts happen.
Definition: Exceptions.h:391
void AppendDebugMethod(std::string method_name, std::string arg1_name="", float arg1_value=-1.0, std::string arg2_name="", float arg2_value=-1.0, std::string arg3_name="", float arg3_value=-1.0, std::string arg4_name="", float arg4_value=-1.0, std::string arg5_name="", float arg5_value=-1.0, std::string arg6_name="", float arg6_value=-1.0)
Append debug information.
Definition: ZmqLogger.cpp:190
static ZmqLogger * Instance()
Create or get an instance of this logger singleton (invoke the class with this method)
Definition: ZmqLogger.cpp:52
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:47
int height
The height of the video (in pixels)
Definition: WriterBase.h:57
int video_bit_rate
The bit rate of the video stream (in bytes)
Definition: WriterBase.h:61
bool has_audio
Determines if this file has an audio stream.
Definition: WriterBase.h:53
std::string vcodec
The name of the video codec used to encode / decode the video stream.
Definition: WriterBase.h:64
bool has_video
Determines if this file has a video stream.
Definition: WriterBase.h:52
openshot::Fraction fps
Frames per second, as a fraction (i.e. 24/1 = 24 fps)
Definition: WriterBase.h:60
openshot::Fraction video_timebase
The video timebase determines how long each frame stays on the screen.
Definition: WriterBase.h:67
openshot::Fraction display_ratio
The ratio of width to height of the video stream (i.e. 640x480 has a ratio of 4/3)
Definition: WriterBase.h:63
int width
The width of the video (in pixels)
Definition: WriterBase.h:58
openshot::Fraction pixel_ratio
The pixel ratio of the video stream as a fraction (i.e. some pixels are not square)
Definition: WriterBase.h:62