libopenshot/src/ImageReader.cpp

/**
 * @file
 * @brief Source file for ImageReader class
 * @author Jonathan Thomas <jonathan@openshot.org>
 *
 * @section LICENSE
 *
 * Copyright (c) 2008-2013 OpenShot Studios, LLC
 * (http://www.openshotstudios.com). This file is part of
 * OpenShot Library (http://www.openshot.org), an open-source project
 * dedicated to delivering high quality video editing and animation solutions
 * to the world.
 *
 * OpenShot Library is free software: you can redistribute it and/or modify
 * it under the terms of the GNU 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 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with OpenShot Library.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "../include/ImageReader.h"

using namespace openshot;

ImageReader::ImageReader(string path) throw(InvalidFile) : path(path), is_open(false)
{
	// Init FileInfo struct (clear all values)
	InitFileInfo();

	// Open and Close the reader, to populate it's attributes (such as height, width, etc...)
	Open();
	Close();
}

// Open image file
void ImageReader::Open() throw(InvalidFile)
{
	// Open reader if not already open
	if (!is_open)
	{
		// Attempt to open file
		try
		{
			// load image
			image = tr1::shared_ptr<Magick::Image>(new Magick::Image(path));

			// Give image a transparent background color
			image->backgroundColor(Magick::Color("none"));
			image->matte(true);
		}
		catch (Magick::Exception e) {
			// raise exception
			throw InvalidFile("File could not be opened.", path);
		}

		// Update image properties
		info.has_audio = false;
		info.has_video = true;
		info.file_size = image->fileSize();
		info.vcodec = image->format();
		info.width = image->size().width();
		info.height = image->size().height();
		info.pixel_ratio.num = 1;
		info.pixel_ratio.den = 1;
		info.duration = 60 * 60 * 24; // 24 hour duration
		info.fps.num = 30;
		info.fps.den = 1;
		info.video_timebase.num = 1;
		info.video_timebase.den = 30;
		info.video_length = round(info.duration * info.fps.ToDouble());

		// Calculate the DAR (display aspect ratio)
		Fraction size(info.width * info.pixel_ratio.num, info.height * info.pixel_ratio.den);

		// Reduce size fraction
		size.Reduce();

		// Set the ratio based on the reduced fraction
		info.display_ratio.num = size.num;
		info.display_ratio.den = size.den;

		// Mark as "open"
		is_open = true;
	}
}

// Close image file
void ImageReader::Close()
{
	// Close all objects, if reader is 'open'
	if (is_open)
	{
		// Mark as "closed"
		is_open = false;
	}
}

// Get an openshot::Frame object for a specific frame number of this reader.
tr1::shared_ptr<Frame> ImageReader::GetFrame(int requested_frame) throw(ReaderClosed)
{
	// Check for open reader (or throw exception)
	if (!is_open)
		throw ReaderClosed("The FFmpegReader is closed.  Call Open() before calling this method.", path);

	// Create or get frame object
	tr1::shared_ptr<Frame> image_frame(new Frame(requested_frame, image->size().width(), image->size().height(), "#000000", 0, 2));
	image_frame->SetSampleRate(44100);

	// Add Image data to frame
	tr1::shared_ptr<Magick::Image> copy_image(new Magick::Image(*image.get()));
	copy_image->modifyImage(); // actually copy the image data to this object
	image_frame->AddImage(copy_image);

	// return frame object
	return image_frame;
}