libopenshot/src/effects/Mask.cpp

/**
 * @file
 * @brief Source file for Mask 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/Mask.h"

using namespace openshot;

/// Blank constructor, useful when using Json to load the effect properties
Mask::Mask() : reader(NULL), replace_image(false) {
	// Init effect properties
	init_effect_details();
}

// Default constructor
Mask::Mask(ReaderBase *mask_reader, Keyframe mask_brightness, Keyframe mask_contrast) throw(InvalidFile, ReaderClosed) :
		reader(mask_reader), brightness(mask_brightness), contrast(mask_contrast), replace_image(false)
{
	// Init effect properties
	init_effect_details();
}

// Init effect settings
void Mask::init_effect_details()
{
	/// Initialize the values of the EffectInfo struct.
	InitEffectInfo();

	/// Set the effect info
	info.class_name = "Mask";
	info.name = "Alpha Mask / Wipe Transition";
	info.description = "Uses a grayscale mask image to gradually wipe / transition between 2 images.";
	info.has_audio = false;
	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
tr1::shared_ptr<QImage> Mask::get_grayscale_mask(tr1::shared_ptr<QImage> mask_frame_image, int width, int height, float brightness, float contrast)
{
	// Get pixels for mask image
	unsigned char *pixels = (unsigned char *) mask_frame_image->bits();

	// Convert the mask image to grayscale
	// Loop through pixels
	for (int pixel = 0, byte_index=0; pixel < mask_frame_image->width() * mask_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];

		// Get the average luminosity
		int gray_value = qGray(R, G, B);

		// Adjust the contrast
		int factor = (259 * (contrast + 255)) / (255 * (259 - contrast));
		gray_value = constrain((factor * (gray_value - 128)) + 128);

		// Adjust the brightness
		gray_value += (255 * brightness);

		// Constrain the value from 0 to 255
		gray_value = constrain(gray_value);

		// Set all pixels to gray value
		pixels[byte_index] = gray_value;
		pixels[byte_index + 1] = gray_value;
		pixels[byte_index + 2] = gray_value;
		pixels[byte_index + 3] = 255;
	}

	// Resize mask image to match frame size
	return tr1::shared_ptr<QImage>(new QImage(mask_frame_image->scaled(width, height, Qt::IgnoreAspectRatio, Qt::SmoothTransformation)));
}

// This method is required for all derived classes of EffectBase, and returns a
// modified openshot::Frame object
tr1::shared_ptr<Frame> Mask::GetFrame(tr1::shared_ptr<Frame> frame, long int frame_number)
{
	// Get the mask image (from the mask reader)
	tr1::shared_ptr<QImage> frame_image = frame->GetImage();

	// Check if mask reader is open
	if (reader && !reader->IsOpen())
		#pragma omp critical (open_mask_reader)
		reader->Open();

	// No reader (bail on applying the mask)
	if (!reader)
		return frame;

	// Get the mask image (from the mask reader)
	tr1::shared_ptr<QImage> mask = tr1::shared_ptr<QImage>(new QImage(*reader->GetFrame(frame_number)->GetImage()));

	// Convert mask to grayscale and resize to frame size
	mask = get_grayscale_mask(mask, frame_image->width(), frame_image->height(), brightness.GetValue(frame_number), contrast.GetValue(frame_number));


	// Get pixels for frame image
	unsigned char *pixels = (unsigned char *) frame_image->bits();
	unsigned char *mask_pixels = (unsigned char *) mask->bits();

	// Convert the mask image to grayscale
	// Loop through pixels
	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 Frame_Alpha = pixels[byte_index + 3];
		int Mask_Value = constrain(Frame_Alpha - (int)mask_pixels[byte_index]); // Red pixel (all colors should have the same value here)

		// Set all pixels to gray value
		pixels[byte_index + 3] = Mask_Value;
	}

	// Replace the frame's image with the current mask (good for debugging)
	if (replace_image)
		frame->AddImage(mask); // not typically called when using a mask

	// return the modified frame
	return frame;
}

// Generate JSON string of this object
string Mask::Json() {

	// Return formatted string
	return JsonValue().toStyledString();
}

// Generate Json::JsonValue for this object
Json::Value Mask::JsonValue() {

	// Create root json object
	Json::Value root = EffectBase::JsonValue(); // get parent properties
	root["type"] = info.class_name;
	root["brightness"] = brightness.JsonValue();
	root["contrast"] = contrast.JsonValue();
	if (reader)
		root["reader"] = reader->JsonValue();
	else
		root["reader"] = Json::objectValue;
	root["replace_image"] = replace_image;

	// return JsonValue
	return root;
}

// Load JSON string into this object
void Mask::SetJson(string value) throw(InvalidJSON) {

	// 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 Mask::SetJsonValue(Json::Value root) {

	// Set parent data
	EffectBase::SetJsonValue(root);

	// Set data from Json (if key is found)
	if (!root["replace_image"].isNull())
		replace_image = root["replace_image"].asBool();
	if (!root["brightness"].isNull())
		brightness.SetJsonValue(root["brightness"]);
	if (!root["contrast"].isNull())
		contrast.SetJsonValue(root["contrast"]);
	if (!root["reader"].isNull()) // does Json contain a reader?
	{

		if (!root["reader"]["type"].isNull()) // does the reader Json contain a 'type'?
		{
			// Close previous reader (if any)
			if (reader)
			{
				// Close and delete existing reader (if any)
				reader->Close();
				delete reader;
				reader = NULL;
			}

			// Create new reader (and load properties)
			string type = root["reader"]["type"].asString();

			if (type == "FFmpegReader") {

				// Create new reader
				reader = new FFmpegReader(root["reader"]["path"].asString());
				reader->SetJsonValue(root["reader"]);

			} else if (type == "ImageReader") {

				// Create new reader
				reader = new ImageReader(root["reader"]["path"].asString());
				reader->SetJsonValue(root["reader"]);

			} else if (type == "QtImageReader") {

				// Create new reader
				reader = new QtImageReader(root["reader"]["path"].asString());
				reader->SetJsonValue(root["reader"]);

			} else if (type == "ChunkReader") {

				// Create new reader
				reader = new ChunkReader(root["reader"]["path"].asString(), (ChunkVersion) root["reader"]["chunk_version"].asInt());
				reader->SetJsonValue(root["reader"]);

			}

		}
	}

}

// Get all properties for a specific frame
string Mask::PropertiesJSON(long int requested_frame) {

	// Requested Point
	Point requested_point(requested_frame, requested_frame);

	// Generate JSON properties list
	Json::Value root;
	root["id"] = add_property_json("ID", 0.0, "string", Id(), false, 0, -1, -1, CONSTANT, -1, true);
	root["position"] = add_property_json("Position", Position(), "float", "", false, 0, 0, 1000 * 60 * 30, CONSTANT, -1, false);
	root["layer"] = add_property_json("Layer", Layer(), "int", "", false, 0, 0, 1000, CONSTANT, -1, false);
	root["start"] = add_property_json("Start", Start(), "float", "", false, 0, 0, 1000 * 60 * 30, CONSTANT, -1, false);
	root["end"] = add_property_json("End", End(), "float", "", false, 0, 0, 1000 * 60 * 30, CONSTANT, -1, false);
	root["duration"] = add_property_json("Duration", Duration(), "float", "", false, 0, 0, 1000 * 60 * 30, CONSTANT, -1, true);
	root["replace_image"] = add_property_json("Replace Image", replace_image, "bool", "", false, 0, 0, 1, CONSTANT, -1, false);

	// Keyframes
	root["brightness"] = add_property_json("Brightness", brightness.GetValue(requested_frame), "float", "", brightness.Contains(requested_point), brightness.GetCount(), -10000, 10000, brightness.GetClosestPoint(requested_point).interpolation, brightness.GetClosestPoint(requested_point).co.X, false);
	root["contrast"] = add_property_json("Contrast", contrast.GetValue(requested_frame), "float", "", contrast.Contains(requested_point), contrast.GetCount(), -10000, 10000, contrast.GetClosestPoint(requested_point).interpolation, contrast.GetClosestPoint(requested_point).co.X, false);

	// Return formatted string
	return root.toStyledString();
}