Mask.cpp

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/**
 * @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), needs_refresh(true) {
        // Init effect properties
        init_effect_details();
}

// Default constructor
Mask::Mask(ReaderBase *mask_reader, Keyframe mask_brightness, Keyframe mask_contrast) :
                reader(mask_reader), brightness(mask_brightness), contrast(mask_contrast), replace_image(false), needs_refresh(true)
{
        // 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;
}

// This method is required for all derived classes of EffectBase, and returns a
// modified openshot::Frame object
std::shared_ptr<Frame> Mask::GetFrame(std::shared_ptr<Frame> frame, int64_t frame_number) {
        // Get the mask image (from the mask reader)
        std::shared_ptr<QImage> frame_image = frame->GetImage();

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

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

        // Get mask image (if missing or different size than frame image)
        #pragma omp critical (open_mask_reader)
        {
                if (!original_mask || !reader->info.has_single_image || needs_refresh ||
                        (original_mask && original_mask->size() != frame_image->size())) {

                        // Only get mask if needed
                        std::shared_ptr<QImage> mask_without_sizing = std::shared_ptr<QImage>(
                                        new QImage(*reader->GetFrame(frame_number)->GetImage()));

                        // Resize mask image to match frame size
                        original_mask = std::shared_ptr<QImage>(new QImage(
                                        mask_without_sizing->scaled(frame_image->width(), frame_image->height(), Qt::IgnoreAspectRatio,
                                                                                                Qt::SmoothTransformation)));
                }
        }

        // Refresh no longer needed
        needs_refresh = false;

        // Get pixel arrays
        unsigned char *pixels = (unsigned char *) frame_image->bits();
        unsigned char *mask_pixels = (unsigned char *) original_mask->bits();

        int R = 0;
        int G = 0;
        int B = 0;
        int A = 0;
        int gray_value = 0;
        float factor = 0.0;
        double contrast_value = (contrast.GetValue(frame_number));
        double brightness_value = (brightness.GetValue(frame_number));

        // Loop through mask pixels, and apply average gray value to frame alpha channel
        for (int pixel = 0, byte_index=0; pixel < original_mask->width() * original_mask->height(); pixel++, byte_index+=4)
        {
                // Get the RGB values from the pixel
                R = mask_pixels[byte_index];
                G = mask_pixels[byte_index + 1];
                B = mask_pixels[byte_index + 2];

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

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

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

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

                // Set the alpha channel to the gray value
                if (replace_image) {
                        // Replace frame pixels with gray value
                        pixels[byte_index + 0] = gray_value;
                        pixels[byte_index + 1] = gray_value;
                        pixels[byte_index + 2] = gray_value;
                } else {
                        // Set alpha channel
                        A = pixels[byte_index + 3];
                        pixels[byte_index + 3] = constrain(A - gray_value);
                }

        }

        // 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) {

        // 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?
        {
                #pragma omp critical (open_mask_reader)
                {
                        // This reader has changed, so refresh cached assets
                        needs_refresh = true;

                        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"]);

        #ifdef USE_IMAGEMAGICK
                                        } else if (type == "ImageReader") {

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

                                } 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(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, 30 * 60 * 60 * 48, 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, 30 * 60 * 60 * 48, false, requested_frame);
        root["end"] = add_property_json("End", End(), "float", "", NULL, 0, 30 * 60 * 60 * 48, false, requested_frame);
        root["duration"] = add_property_json("Duration", Duration(), "float", "", NULL, 0, 30 * 60 * 60 * 48, true, requested_frame);