ImageReader.cpp
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/**
* @file
* @brief Source file for ImageReader class
* @author Jonathan Thomas <jonathan@openshot.org>
*
* @ref License
*/
/* LICENSE
*
* Copyright (c) 2008-2019 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/>.
*/
// Require ImageMagick support
#ifdef USE_IMAGEMAGICK
#include "../include/ImageReader.h"
using namespace openshot;
ImageReader::ImageReader(std::string path) : path(path), is_open(false)
{
// Open and Close the reader, to populate its attributes (such as height, width, etc...)
Open();
Close();
}
ImageReader::ImageReader(std::string path, bool inspect_reader) : path(path), is_open(false)
{
// Open and Close the reader, to populate its attributes (such as height, width, etc...)
if (inspect_reader) {
Open();
Close();
}
}
// Open image file
void ImageReader::Open()
{
// Open reader if not already open
if (!is_open)
{
// Attempt to open file
try
{
// load image
image = std::shared_ptr<Magick::Image>(new Magick::Image(path));
// Give image a transparent background color
image->backgroundColor(Magick::Color("none"));
MAGICK_IMAGE_ALPHA(image, true);
}
catch (const 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.has_single_image = 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 * 1; // 1 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;
// Delete the image
image.reset();
}
}
// Get an openshot::Frame object for a specific frame number of this reader.
std::shared_ptr<Frame> ImageReader::GetFrame(int64_t requested_frame)
{
// 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
std::shared_ptr<Frame> image_frame(new Frame(requested_frame, image->size().width(), image->size().height(), "#000000", 0, 2));
// Add Image data to frame
image_frame->AddMagickImage(image);
// return frame object
return image_frame;
}
// Generate JSON string of this object
std::string ImageReader::Json() const {
// Return formatted string
return JsonValue().toStyledString();
}
// Generate Json::Value for this object
Json::Value ImageReader::JsonValue() const {
// Create root json object
Json::Value root = ReaderBase::JsonValue(); // get parent properties
root["type"] = "ImageReader";
root["path"] = path;
// return JsonValue
return root;
}
// Load JSON string into this object
void ImageReader::SetJson(const std::string value) {
// Parse JSON string into JSON objects
try
{
const Json::Value root = openshot::stringToJson(value);
// Set all values that match
SetJsonValue(root);
}
catch (const std::exception& e)
{
// Error parsing JSON (or missing keys)
throw InvalidJSON("JSON is invalid (missing keys or invalid data types)");
}
}
// Load Json::Value into this object
void ImageReader::SetJsonValue(const Json::Value root) {
// Set parent data
ReaderBase::SetJsonValue(root);
// Set data from Json (if key is found)
if (!root["path"].isNull())
path = root["path"].asString();
// Re-Open path, and re-init everything (if needed)
if (is_open)
{
Close();
Open();
}
}
#endif //USE_IMAGEMAGICK
MAGICK_IMAGE_ALPHA
#define MAGICK_IMAGE_ALPHA(im, a)
Definition: MagickUtilities.h:48
openshot::Fraction
This class represents a fraction.
Definition: Fraction.h:45
openshot::Fraction::num
int num
Numerator for the fraction.
Definition: Fraction.h:47
openshot::Fraction::ToDouble
double ToDouble()
Return this fraction as a double (i.e. 1/2 = 0.5)
Definition: Fraction.cpp:49
openshot::Fraction::Reduce
void Reduce()
Reduce this fraction (i.e. 640/480 = 4/3)
Definition: Fraction.cpp:74
openshot::Fraction::den
int den
Denominator for the fraction.
Definition: Fraction.h:48
openshot::Frame
This class represents a single frame of video (i.e. image & audio data)
Definition: Frame.h:107
openshot::ImageReader::ImageReader
ImageReader(std::string path)
Definition: ImageReader.cpp:38
openshot::ImageReader::JsonValue
Json::Value JsonValue() const
Generate Json::Value for this object.
Definition: ImageReader.cpp:146
openshot::ImageReader::SetJsonValue
void SetJsonValue(const Json::Value root)
Load Json::Value into this object.
Definition: ImageReader.cpp:175
openshot::ImageReader::SetJson
void SetJson(const std::string value)
Load JSON string into this object.
Definition: ImageReader.cpp:158
openshot::ImageReader::Open
void Open()
Open File - which is called by the constructor automatically.
Definition: ImageReader.cpp:55
openshot::ImageReader::Close
void Close()
Close File.
Definition: ImageReader.cpp:108
openshot::ImageReader::GetFrame
std::shared_ptr< Frame > GetFrame(int64_t requested_frame)
Definition: ImageReader.cpp:122
openshot::ImageReader::Json
std::string Json() const override
Get and Set JSON methods.
Definition: ImageReader.cpp:139
openshot::InvalidFile
Exception for files that can not be found or opened.
Definition: Exceptions.h:174
openshot::InvalidJSON
Exception for invalid JSON.
Definition: Exceptions.h:206
openshot::ReaderBase::info
openshot::ReaderInfo info
Information about the current media file.
Definition: ReaderBase.h:111
openshot::ReaderBase::SetJsonValue
virtual void SetJsonValue(const Json::Value root)=0
Load Json::Value into this object.
Definition: ReaderBase.cpp:171
openshot::ReaderBase::JsonValue
virtual Json::Value JsonValue() const =0
Generate Json::Value for this object.
Definition: ReaderBase.cpp:116
openshot::ReaderClosed
Exception when a reader is closed, and a frame is requested.
Definition: Exceptions.h:338
openshot
This namespace is the default namespace for all code in the openshot library.
Definition: AudioBufferSource.h:39
openshot::stringToJson
const Json::Value stringToJson(const std::string value)
Definition: Json.cpp:33
openshot::ReaderInfo::has_single_image
bool has_single_image
Determines if this file only contains a single image.
Definition: ReaderBase.h:64
openshot::ReaderInfo::duration
float duration
Length of time (in seconds)
Definition: ReaderBase.h:65
openshot::ReaderInfo::width
int width
The width of the video (in pixesl)
Definition: ReaderBase.h:68
openshot::ReaderInfo::fps
openshot::Fraction fps
Frames per second, as a fraction (i.e. 24/1 = 24 fps)
Definition: ReaderBase.h:70
openshot::ReaderInfo::display_ratio
openshot::Fraction display_ratio
The ratio of width to height of the video stream (i.e. 640x480 has a ratio of 4/3)
Definition: ReaderBase.h:73
openshot::ReaderInfo::height
int height
The height of the video (in pixels)
Definition: ReaderBase.h:67
openshot::ReaderInfo::video_length
int64_t video_length
The number of frames in the video stream.
Definition: ReaderBase.h:75
openshot::ReaderInfo::vcodec
std::string vcodec
The name of the video codec used to encode / decode the video stream.
Definition: ReaderBase.h:74
openshot::ReaderInfo::pixel_ratio
openshot::Fraction pixel_ratio
The pixel ratio of the video stream as a fraction (i.e. some pixels are not square)
Definition: ReaderBase.h:72
openshot::ReaderInfo::has_video
bool has_video
Determines if this file has a video stream.
Definition: ReaderBase.h:62
openshot::ReaderInfo::has_audio
bool has_audio
Determines if this file has an audio stream.
Definition: ReaderBase.h:63
openshot::ReaderInfo::video_timebase
openshot::Fraction video_timebase
The video timebase determines how long each frame stays on the screen.
Definition: ReaderBase.h:77
openshot::ReaderInfo::file_size
int64_t file_size
Size of file (in bytes)
Definition: ReaderBase.h:66