OpenShot Library | libopenshot 0.3.3
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Brightness.cpp
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1
9// Copyright (c) 2008-2019 OpenShot Studios, LLC
10//
11// SPDX-License-Identifier: LGPL-3.0-or-later
12
13#include "Brightness.h"
14#include "Exceptions.h"
15
16using namespace openshot;
17
19Brightness::Brightness() : brightness(0.0), contrast(3.0) {
20 // Init effect properties
21 init_effect_details();
22}
23
24// Default constructor
25Brightness::Brightness(Keyframe new_brightness, Keyframe new_contrast) : brightness(new_brightness), contrast(new_contrast)
26{
27 // Init effect properties
28 init_effect_details();
29}
30
31// Init effect settings
32void Brightness::init_effect_details()
33{
36
38 info.class_name = "Brightness";
39 info.name = "Brightness & Contrast";
40 info.description = "Adjust the brightness and contrast of the frame's image.";
41 info.has_audio = false;
42 info.has_video = true;
43}
44
45// This method is required for all derived classes of EffectBase, and returns a
46// modified openshot::Frame object
47std::shared_ptr<openshot::Frame> Brightness::GetFrame(std::shared_ptr<openshot::Frame> frame, int64_t frame_number)
48{
49 // Get the frame's image
50 std::shared_ptr<QImage> frame_image = frame->GetImage();
51
52 // Get keyframe values for this frame
53 float brightness_value = brightness.GetValue(frame_number);
54 float contrast_value = contrast.GetValue(frame_number);
55
56 // Loop through pixels
57 unsigned char *pixels = (unsigned char *) frame_image->bits();
58 int pixel_count = frame_image->width() * frame_image->height();
59
60 #pragma omp parallel for
61 for (int pixel = 0; pixel < pixel_count; ++pixel)
62 {
63 // Compute contrast adjustment factor
64 float factor = (259 * (contrast_value + 255)) / (255 * (259 - contrast_value));
65
66 // Calculate alpha % (to be used for removing pre-multiplied alpha value)
67 int A = pixels[pixel * 4 + 3];
68 float alpha_percent = A / 255.0;
69
70 // Get RGB values, and remove pre-multiplied alpha
71 unsigned char R = pixels[pixel * 4 + 0] / alpha_percent;
72 unsigned char G = pixels[pixel * 4 + 1] / alpha_percent;
73 unsigned char B = pixels[pixel * 4 + 2] / alpha_percent;
74
75 // Apply constrained contrast adjustment
76 R = constrain((factor * (R - 128)) + 128);
77 G = constrain((factor * (G - 128)) + 128);
78 B = constrain((factor * (B - 128)) + 128);
79
80 // Adjust brightness and write constrained values back to image
81 pixels[pixel * 4 + 0] = constrain(R + (255 * brightness_value));
82 pixels[pixel * 4 + 1] = constrain(G + (255 * brightness_value));
83 pixels[pixel * 4 + 2] = constrain(B + (255 * brightness_value));
84
85 // Pre-multiply the alpha back into the color channels
86 pixels[pixel * 4 + 0] *= alpha_percent;
87 pixels[pixel * 4 + 1] *= alpha_percent;
88 pixels[pixel * 4 + 2] *= alpha_percent;
89 }
90
91 // return the modified frame
92 return frame;
93}
94
95// Generate JSON string of this object
96std::string Brightness::Json() const {
97
98 // Return formatted string
99 return JsonValue().toStyledString();
100}
101
102// Generate Json::Value for this object
103Json::Value Brightness::JsonValue() const {
104
105 // Create root json object
106 Json::Value root = EffectBase::JsonValue(); // get parent properties
107 root["type"] = info.class_name;
108 root["brightness"] = brightness.JsonValue();
109 root["contrast"] = contrast.JsonValue();
110
111 // return JsonValue
112 return root;
113}
114
115// Load JSON string into this object
116void Brightness::SetJson(const std::string value) {
117
118 // Parse JSON string into JSON objects
119 try
120 {
121 const Json::Value root = openshot::stringToJson(value);
122 // Set all values that match
123 SetJsonValue(root);
124 }
125 catch (const std::exception& e)
126 {
127 // Error parsing JSON (or missing keys)
128 throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
129 }
130}
131
132// Load Json::Value into this object
133void Brightness::SetJsonValue(const Json::Value root) {
134
135 // Set parent data
137
138 // Set data from Json (if key is found)
139 if (!root["brightness"].isNull())
140 brightness.SetJsonValue(root["brightness"]);
141 if (!root["contrast"].isNull())
142 contrast.SetJsonValue(root["contrast"]);
143}
144
145// Get all properties for a specific frame
146std::string Brightness::PropertiesJSON(int64_t requested_frame) const {
147
148 // Generate JSON properties list
149 Json::Value root = BasePropertiesJSON(requested_frame);
150
151 // Keyframes
152 root["brightness"] = add_property_json("Brightness", brightness.GetValue(requested_frame), "float", "", &brightness, -1.0, 1.0, false, requested_frame);
153 root["contrast"] = add_property_json("Contrast", contrast.GetValue(requested_frame), "float", "", &contrast, -128, 128.0, false, requested_frame);
154
155 // Return formatted string
156 return root.toStyledString();
157}
Header file for Brightness class.
Header file for all Exception classes.
Keyframe brightness
Brightness keyframe. A constant value here will prevent animation.
Definition Brightness.h:41
std::string Json() const override
Generate JSON string of this object.
Keyframe contrast
Contrast keyframe.
Definition Brightness.h:42
std::shared_ptr< openshot::Frame > GetFrame(int64_t frame_number) override
This method is required for all derived classes of ClipBase, and returns a new openshot::Frame object...
Definition Brightness.h:60
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 PropertiesJSON(int64_t requested_frame) const override
Brightness()
Blank constructor, useful when using Json to load the effect properties.
void SetJson(const std::string value) override
Load JSON string into this object.
Json::Value add_property_json(std::string name, float value, std::string type, std::string memo, const Keyframe *keyframe, float min_value, float max_value, bool readonly, int64_t requested_frame) const
Generate JSON for a property.
Definition ClipBase.cpp:96
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
int constrain(int color_value)
Constrain a color value from 0 to 255.
Json::Value BasePropertiesJSON(int64_t requested_frame) const
Generate JSON object of base properties (recommended to be used by all effects)
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
EffectInfoStruct info
Information about the current effect.
Definition EffectBase.h:69
Exception for invalid JSON.
Definition Exceptions.h:218
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition KeyFrame.h:53
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition KeyFrame.cpp:372
double GetValue(int64_t index) const
Get the value at a specific index.
Definition KeyFrame.cpp:258
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition KeyFrame.cpp:339
This namespace is the default namespace for all code in the openshot library.
Definition Compressor.h:29
const Json::Value stringToJson(const std::string value)
Definition Json.cpp:16
bool has_video
Determines if this effect manipulates the image of a frame.
Definition EffectBase.h:40
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition EffectBase.h:41
std::string class_name
The class name of the effect.
Definition EffectBase.h:36
std::string name
The name of the effect.
Definition EffectBase.h:37
std::string description
The description of this effect and what it does.
Definition EffectBase.h:38