subsurface/core/imagedownloader.h
Berthold Stoeger fce42d4858 Dive media: Extract thumbnails from videos with ffmpeg
Extract thumbnails using ffmpeg.
Behavior is controlled by three new preferences fields:
 - extract_video_thumbnails (bool): if true, thumbnails are calculated.
 - extract_video_thumbnail_position (int 0..100): position in video
   where thumbnail is fetched.
 - ffmpeg_executable (string): path of ffmpeg executable.

If ffmpeg refuses to start, extract_video_thumbnails is set to false
to avoid unnecessary churn.

Video thumbnails are marked by an overlay.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>
2018-07-28 15:31:25 -07:00

87 lines
3.1 KiB
C++

// SPDX-License-Identifier: GPL-2.0
#ifndef IMAGEDOWNLOADER_H
#define IMAGEDOWNLOADER_H
#include "metadata.h"
#include <QImage>
#include <QFuture>
#include <QNetworkReply>
#include <QThreadPool>
class ImageDownloader : public QObject {
Q_OBJECT
public:
static ImageDownloader *instance();
ImageDownloader();
public slots:
void load(QUrl url, QString filename);
signals:
void loaded(QString filename);
void failed(QString filename);
private:
QNetworkAccessManager manager;
void loadFromUrl(const QString &filename, const QUrl &);
void saveImage(QNetworkReply *reply);
};
struct PictureEntry;
class Thumbnailer : public QObject {
Q_OBJECT
public:
static Thumbnailer *instance();
// Schedule a thumbnail for fetching or calculation.
// Returns a placeholder thumbnail. The actual thumbnail will be sent
// via a signal later.
QImage fetchThumbnail(const QString &filename);
// Schedule multiple thumbnails for forced recalculation
void calculateThumbnails(const QVector<QString> &filenames);
// If we change dive, clear all unfinished thumbnail creations
void clearWorkQueue();
static int maxThumbnailSize();
static int defaultThumbnailSize();
static int thumbnailSize(double zoomLevel);
public slots:
void imageDownloaded(QString filename);
void imageDownloadFailed(QString filename);
void frameExtracted(QString filename, QImage thumbnail, duration_t duration, duration_t offset);
void frameExtractionFailed(QString filename, duration_t duration);
void frameExtractionInvalid(QString filename, duration_t duration);
signals:
void thumbnailChanged(QString filename, QImage thumbnail, duration_t duration);
private:
struct Thumbnail {
QImage img;
mediatype_t type;
duration_t duration;
};
Thumbnailer();
Thumbnail fetchVideoThumbnail(const QString &filename, const QString &originalFilename, duration_t duration);
Thumbnail extractVideoThumbnail(const QString &picture_filename, duration_t duration);
Thumbnail addPictureThumbnailToCache(const QString &picture_filename, const QImage &thumbnail);
Thumbnail addVideoThumbnailToCache(const QString &picture_filename, duration_t duration, const QImage &thumbnail, duration_t position);
Thumbnail addUnknownThumbnailToCache(const QString &picture_filename);
void recalculate(QString filename);
void processItem(QString filename, bool tryDownload);
Thumbnail getThumbnailFromCache(const QString &picture_filename);
Thumbnail getPictureThumbnailFromStream(QDataStream &stream);
Thumbnail getVideoThumbnailFromStream(QDataStream &stream, const QString &filename);
Thumbnail fetchImage(const QString &filename, const QString &originalFilename, bool tryDownload);
Thumbnail getHashedImage(const QString &filename, bool tryDownload);
void markVideoThumbnail(QImage &img);
mutable QMutex lock;
QThreadPool pool;
QImage failImage; // Shown when image-fetching fails
QImage dummyImage; // Shown before thumbnail is fetched
QImage videoImage; // Place holder for videos
QImage videoOverlayImage; // Overlay for video thumbnails
QImage unknownImage; // Place holder for files where we couldn't determine the type
QMap<QString,QFuture<void>> workingOn;
};
#endif // IMAGEDOWNLOADER_H