Adding Hue video effect, to adjust the hue of a frame's image, which can also be animated with a keyframe

src/EffectBase.cpp

@@ -58,6 +58,18 @@ void EffectBase::DisplayInfo() {
 	cout << "----------------------------" << endl;
 }
 
+// Constrain a color value from 0 to 255
+int EffectBase::constrain(int color_value)
+{
+	// Constrain new color from 0 to 255
+	if (color_value < 0)
+		color_value = 0;
+	else if (color_value > 255)
+		color_value = 255;
+
+	return color_value;
+}
+
 // Generate JSON string of this object
 string EffectBase::Json() {
 

src/EffectInfo.cpp

@@ -53,6 +53,9 @@ EffectBase* EffectInfo::CreateEffect(string effect_type) {
 	else if (effect_type == "Deinterlace")
 		return new Deinterlace();
 
+	else if (effect_type == "Hue")
+		return new Hue();
+
 	else if (effect_type == "Mask")
 		return new Mask();
 
@@ -77,6 +80,7 @@ Json::Value EffectInfo::JsonValue() {
 	root.append(Brightness().JsonInfo());
 	root.append(ChromaKey().JsonInfo());
 	root.append(Deinterlace().JsonInfo());
+	root.append(Hue().JsonInfo());
 	root.append(Mask().JsonInfo());
 	root.append(Negate().JsonInfo());
 	root.append(Saturation().JsonInfo());

src/bindings/python/openshot.i

@@ -164,6 +164,7 @@
 %include "../../../include/effects/Brightness.h"
 %include "../../../include/effects/ChromaKey.h"
 %include "../../../include/effects/Deinterlace.h"
+%include "../../../include/effects/Hue.h"
 %include "../../../include/effects/Mask.h"
 %include "../../../include/effects/Negate.h"
 %include "../../../include/effects/Saturation.h"

src/bindings/ruby/openshot.i

@@ -157,6 +157,7 @@ namespace std {
 %include "../../../include/effects/Brightness.h"
 %include "../../../include/effects/ChromaKey.h"
 %include "../../../include/effects/Deinterlace.h"
+%include "../../../include/effects/Hue.h"
 %include "../../../include/effects/Mask.h"
 %include "../../../include/effects/Negate.h"
 %include "../../../include/effects/Saturation.h"

src/effects/Brightness.cpp

@@ -56,19 +56,6 @@ void Brightness::init_effect_details()
 	info.has_video = true;
 }
 
-// Constrain a color value from 0 to 255
-int Brightness::constrain(int color_value)
-{
-	// Constrain new color from 0 to 255
-	if (color_value < 0)
-		color_value = 0;
-	else if (color_value > 255)
-		color_value = 255;
-
-	return color_value;
-}
-
-
 // This method is required for all derived classes of EffectBase, and returns a
 // modified openshot::Frame object
 std::shared_ptr<Frame> Brightness::GetFrame(std::shared_ptr<Frame> frame, int64_t frame_number)

src/effects/Hue.cpp

@@ -0,0 +1,173 @@
+/**
+ * @file
+ * @brief Source file for Hue effect class
+ * @author Jonathan Thomas <jonathan@openshot.org>
+ *
+ * @section LICENSE
+ *
+ * Copyright (c) 2008-2014 OpenShot Studios, LLC
+ * <http://www.openshotstudios.com/>. This file is part of
+ * OpenShot Library (libopenshot), an open-source project dedicated to
+ * delivering high quality video editing and animation solutions to the
+ * world. For more information visit <http://www.openshot.org/>.
+ *
+ * OpenShot Library (libopenshot) is free software: you can redistribute it
+ * and/or modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * OpenShot Library (libopenshot) is distributed in the hope that it will be
+ * useful, but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with OpenShot Library. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "../../include/effects/Hue.h"
+
+using namespace openshot;
+
+/// Blank constructor, useful when using Json to load the effect properties
+Hue::Hue() : Hue(0.0) {
+	// Init effect properties
+	init_effect_details();
+}
+
+// Default constructor
+Hue::Hue(Keyframe hue): hue(hue)
+{
+	// Init effect properties
+	init_effect_details();
+}
+
+// Init effect settings
+void Hue::init_effect_details()
+{
+	/// Initialize the values of the EffectInfo struct.
+	InitEffectInfo();
+
+	/// Set the effect info
+	info.class_name = "Hue";
+	info.name = "Hue";
+	info.description = "Adjust the hue / color of the frame's image.";
+	info.has_audio = false;
+	info.has_video = true;
+}
+
+// This method is required for all derived classes of EffectBase, and returns a
+// modified openshot::Frame object
+std::shared_ptr<Frame> Hue::GetFrame(std::shared_ptr<Frame> frame, int64_t frame_number)
+{
+	// Get the frame's image
+	std::shared_ptr<QImage> frame_image = frame->GetImage();
+
+	// Get the current hue percentage shift amount, and convert to degrees
+	double degrees = 360.0 * hue.GetValue(frame_number);
+	float cosA = cos(degrees*3.14159265f/180);
+	float sinA = sin(degrees*3.14159265f/180);
+
+	// Calculate a rotation matrix for the RGB colorspace (based on the current hue shift keyframe value)
+	float matrix[3][3] = {{cosA + (1.0f - cosA) / 3.0f, 1.0f/3.0f * (1.0f - cosA) - sqrtf(1.0f/3.0f) * sinA, 1.0f/3.0f * (1.0f - cosA) + sqrtf(1.0f/3.0f) * sinA},
+						  {1.0f/3.0f * (1.0f - cosA) + sqrtf(1.0f/3.0f) * sinA, cosA + 1.0f/3.0f*(1.0f - cosA), 1.0f/3.0f * (1.0f - cosA) - sqrtf(1.0f/3.0f) * sinA},
+						  {1.0f/3.0f * (1.0f - cosA) - sqrtf(1.0f/3.0f) * sinA, 1.0f/3.0f * (1.0f - cosA) + sqrtf(1.0f/3.0f) * sinA, cosA + 1.0f/3.0f * (1.0f - cosA)}};
+
+	// Loop through pixels
+	unsigned char *pixels = (unsigned char *) frame_image->bits();
+	for (int pixel = 0, byte_index=0; pixel < frame_image->width() * frame_image->height(); pixel++, byte_index+=4)
+	{
+		// Get the RGB values from the pixel
+		int R = pixels[byte_index];
+		int G = pixels[byte_index + 1];
+		int B = pixels[byte_index + 2];
+		int A = pixels[byte_index + 3];
+
+		// Multiply each color by the hue rotation matrix
+		float rx = constrain(R * matrix[0][0] + G * matrix[0][1] + B * matrix[0][2]);
+		float gx = constrain(R * matrix[1][0] + G * matrix[1][1] + B * matrix[1][2]);
+		float bx = constrain(R * matrix[2][0] + G * matrix[2][1] + B * matrix[2][2]);
+
+		// Set all pixels to new value
+		pixels[byte_index] = rx;
+		pixels[byte_index + 1] = gx;
+		pixels[byte_index + 2] = bx;
+		pixels[byte_index + 3] = A; // leave the alpha value alone
+	}
+
+	// return the modified frame
+	return frame;
+}
+
+// Generate JSON string of this object
+string Hue::Json() {
+
+	// Return formatted string
+	return JsonValue().toStyledString();
+}
+
+// Generate Json::JsonValue for this object
+Json::Value Hue::JsonValue() {
+
+	// Create root json object
+	Json::Value root = EffectBase::JsonValue(); // get parent properties
+	root["type"] = info.class_name;
+	root["hue"] = hue.JsonValue();
+
+	// return JsonValue
+	return root;
+}
+
+// Load JSON string into this object
+void Hue::SetJson(string value) {
+
+	// Parse JSON string into JSON objects
+	Json::Value root;
+	Json::Reader reader;
+	bool success = reader.parse( value, root );
+	if (!success)
+		// Raise exception
+		throw InvalidJSON("JSON could not be parsed (or is invalid)", "");
+
+	try
+	{
+		// Set all values that match
+		SetJsonValue(root);
+	}
+	catch (exception e)
+	{
+		// Error parsing JSON (or missing keys)
+		throw InvalidJSON("JSON is invalid (missing keys or invalid data types)", "");
+	}
+}
+
+// Load Json::JsonValue into this object
+void Hue::SetJsonValue(Json::Value root) {
+
+	// Set parent data
+	EffectBase::SetJsonValue(root);
+
+	// Set data from Json (if key is found)
+	if (!root["hue"].isNull())
+		hue.SetJsonValue(root["hue"]);
+}
+
+// Get all properties for a specific frame
+string Hue::PropertiesJSON(int64_t requested_frame) {
+
+	// Generate JSON properties list
+	Json::Value root;
+	root["id"] = add_property_json("ID", 0.0, "string", Id(), NULL, -1, -1, true, requested_frame);
+	root["position"] = add_property_json("Position", Position(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
+	root["layer"] = add_property_json("Track", Layer(), "int", "", NULL, 0, 20, false, requested_frame);
+	root["start"] = add_property_json("Start", Start(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
+	root["end"] = add_property_json("End", End(), "float", "", NULL, 0, 1000 * 60 * 30, false, requested_frame);
+	root["duration"] = add_property_json("Duration", Duration(), "float", "", NULL, 0, 1000 * 60 * 30, true, requested_frame);
+
+	// Keyframes
+	root["hue"] = add_property_json("Hue", hue.GetValue(requested_frame), "float", "", &hue, 0.0, 1.0, false, requested_frame);
+
+	// Return formatted string
+	return root.toStyledString();
+}
+

src/effects/Mask.cpp

@@ -57,18 +57,6 @@ void Mask::init_effect_details()
 	info.has_video = true;
 }
 
-// Constrain a color value from 0 to 255
-int Mask::constrain(int color_value)
-{
-	// Constrain new color from 0 to 255
-	if (color_value < 0)
-		color_value = 0;
-	else if (color_value > 255)
-		color_value = 255;
-
-	return color_value;
-}
-
 // Get grayscale mask image
 void Mask::set_grayscale_mask(std::shared_ptr<QImage> mask_frame_image, int width, int height, float brightness, float contrast)
 {

src/effects/Saturation.cpp

@@ -56,18 +56,6 @@ void Saturation::init_effect_details()
 	info.has_video = true;
 }
 
-// Constrain a color value from 0 to 255
-int Saturation::constrain(int color_value)
-{
-	// Constrain new color from 0 to 255
-	if (color_value < 0)
-		color_value = 0;
-	else if (color_value > 255)
-		color_value = 255;
-
-	return color_value;
-}
-
 // This method is required for all derived classes of EffectBase, and returns a
 // modified openshot::Frame object
 std::shared_ptr<Frame> Saturation::GetFrame(std::shared_ptr<Frame> frame, int64_t frame_number)

src/effects/Shift.cpp

@@ -36,7 +36,7 @@ Shift::Shift() : x(0.0), y(0.0) {
 }
 
 // Default constructor
-Shift::Shift(Keyframe x, Keyframe y)
+Shift::Shift(Keyframe x, Keyframe y) : x(x), y(y)
 {
 	// Init effect properties
 	init_effect_details();
@@ -51,7 +51,7 @@ void Shift::init_effect_details()
 	/// Set the effect info
 	info.class_name = "Shift";
 	info.name = "Shift";
-	info.description = "Shift the image up, down, left, and right (with infinite wrapping)";
+	info.description = "Shift the image up, down, left, and right (with infinite wrapping).";
 	info.has_audio = false;
 	info.has_video = true;
 }