OpenShot Library | libopenshot  0.3.2
Hue.cpp
Go to the documentation of this file.
1 
9 // Copyright (c) 2008-2019 OpenShot Studios, LLC
10 //
11 // SPDX-License-Identifier: LGPL-3.0-or-later
12 
13 #include "Hue.h"
14 #include "Exceptions.h"
15 
16 using namespace openshot;
17 
19 Hue::Hue() : Hue(0.0) {
20  // Init effect properties
21  init_effect_details();
22 }
23 
24 // Default constructor
25 Hue::Hue(Keyframe hue): hue(hue)
26 {
27  // Init effect properties
28  init_effect_details();
29 }
30 
31 // Init effect settings
32 void Hue::init_effect_details()
33 {
36 
38  info.class_name = "Hue";
39  info.name = "Hue";
40  info.description = "Adjust the hue / color 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
47 std::shared_ptr<openshot::Frame> Hue::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  int pixel_count = frame_image->width() * frame_image->height();
53 
54  // Get the current hue percentage shift amount, and convert to degrees
55  double degrees = 360.0 * hue.GetValue(frame_number);
56  float cosA = cos(degrees*3.14159265f/180);
57  float sinA = sin(degrees*3.14159265f/180);
58 
59  // Calculate a rotation matrix for the RGB colorspace (based on the current hue shift keyframe value)
60  float matrix[3] = {
61  cosA + (1.0f - cosA) / 3.0f,
62  1.0f/3.0f * (1.0f - cosA) - sqrtf(1.0f/3.0f) * sinA,
63  1.0f/3.0f * (1.0f - cosA) + sqrtf(1.0f/3.0f) * sinA
64  };
65 
66  // Loop through pixels
67  unsigned char *pixels = (unsigned char *) frame_image->bits();
68 
69  #pragma omp parallel for shared (pixels)
70  for (int pixel = 0; pixel < pixel_count; ++pixel)
71  {
72  // Calculate alpha % (to be used for removing pre-multiplied alpha value)
73  int A = pixels[pixel * 4 + 3];
74  float alpha_percent = A / 255.0;
75 
76  // Get RGB values, and remove pre-multiplied alpha
77  int R = pixels[pixel * 4 + 0] / alpha_percent;
78  int G = pixels[pixel * 4 + 1] / alpha_percent;
79  int B = pixels[pixel * 4 + 2] / alpha_percent;
80 
81  // Multiply each color by the hue rotation matrix
82  pixels[pixel * 4] = constrain(R * matrix[0] + G * matrix[1] + B * matrix[2]);
83  pixels[pixel * 4 + 1] = constrain(R * matrix[2] + G * matrix[0] + B * matrix[1]);
84  pixels[pixel * 4 + 2] = constrain(R * matrix[1] + G * matrix[2] + B * matrix[0]);
85 
86  // Pre-multiply the alpha back into the color channels
87  pixels[pixel * 4 + 0] *= alpha_percent;
88  pixels[pixel * 4 + 1] *= alpha_percent;
89  pixels[pixel * 4 + 2] *= alpha_percent;
90  }
91 
92  // return the modified frame
93  return frame;
94 }
95 
96 // Generate JSON string of this object
97 std::string Hue::Json() const {
98 
99  // Return formatted string
100  return JsonValue().toStyledString();
101 }
102 
103 // Generate Json::Value for this object
104 Json::Value Hue::JsonValue() const {
105 
106  // Create root json object
107  Json::Value root = EffectBase::JsonValue(); // get parent properties
108  root["type"] = info.class_name;
109  root["hue"] = hue.JsonValue();
110 
111  // return JsonValue
112  return root;
113 }
114 
115 // Load JSON string into this object
116 void Hue::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
133 void Hue::SetJsonValue(const Json::Value root) {
134 
135  // Set parent data
137 
138  // Set data from Json (if key is found)
139  if (!root["hue"].isNull())
140  hue.SetJsonValue(root["hue"]);
141 }
142 
143 // Get all properties for a specific frame
144 std::string Hue::PropertiesJSON(int64_t requested_frame) const {
145 
146  // Generate JSON properties list
147  Json::Value root = BasePropertiesJSON(requested_frame);
148 
149  // Keyframes
150  root["hue"] = add_property_json("Hue", hue.GetValue(requested_frame), "float", "", &hue, 0.0, 1.0, false, requested_frame);
151 
152  // Return formatted string
153  return root.toStyledString();
154 }
openshot::ClipBase::add_property_json
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
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:16
openshot::EffectBase::info
EffectInfoStruct info
Information about the current effect.
Definition: EffectBase.h:69
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: Compressor.h:28
openshot::EffectBase::JsonValue
virtual Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: EffectBase.cpp:79
openshot::Hue::SetJsonValue
void SetJsonValue(const Json::Value root) override
Load Json::Value into this object.
Definition: Hue.cpp:133
openshot::Hue::JsonValue
Json::Value JsonValue() const override
Generate Json::Value for this object.
Definition: Hue.cpp:104
openshot::Keyframe::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: KeyFrame.cpp:372
openshot::Keyframe::JsonValue
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: KeyFrame.cpp:339
openshot::Hue::PropertiesJSON
std::string PropertiesJSON(int64_t requested_frame) const override
Definition: Hue.cpp:144
openshot::EffectBase::BasePropertiesJSON
Json::Value BasePropertiesJSON(int64_t requested_frame) const
Generate JSON object of base properties (recommended to be used by all effects)
Definition: EffectBase.cpp:179
openshot::Hue::hue
Keyframe hue
Shift the hue coordinates (left or right)
Definition: Hue.h:43
openshot::Keyframe
A Keyframe is a collection of Point instances, which is used to vary a number or property over time.
Definition: KeyFrame.h:53
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:217
openshot::Hue::GetFrame
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: Hue.h:59
openshot::Hue::Json
std::string Json() const override
Generate JSON string of this object.
Definition: Hue.cpp:97
openshot::EffectBase::InitEffectInfo
void InitEffectInfo()
Definition: EffectBase.cpp:24
openshot::EffectInfoStruct::has_audio
bool has_audio
Determines if this effect manipulates the audio of a frame.
Definition: EffectBase.h:41
openshot::Hue::Hue
Hue()
Default constructor, useful when using Json to load the effect properties.
Definition: Hue.cpp:19
openshot::Hue
This class shifts the hue of an image, and can be animated with openshot::Keyframe curves over time.
Definition: Hue.h:35
Hue.h
Header file for Hue effect class.
openshot::Hue::SetJson
void SetJson(const std::string value) override
Load JSON string into this object.
Definition: Hue.cpp:116
openshot::EffectInfoStruct::class_name
std::string class_name
The class name of the effect.
Definition: EffectBase.h:36
openshot::EffectInfoStruct::description
std::string description
The description of this effect and what it does.
Definition: EffectBase.h:38
openshot::EffectInfoStruct::has_video
bool has_video
Determines if this effect manipulates the image of a frame.
Definition: EffectBase.h:40
openshot::EffectBase::constrain
int constrain(int color_value)
Constrain a color value from 0 to 255.
Definition: EffectBase.cpp:60
openshot::EffectInfoStruct::name
std::string name
The name of the effect.
Definition: EffectBase.h:37
Exceptions.h
Header file for all Exception classes.
openshot::EffectBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: EffectBase.cpp:115
openshot::Keyframe::GetValue
double GetValue(int64_t index) const
Get the value at a specific index.
Definition: KeyFrame.cpp:258