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>

1 files changed, 52 insertions, 0 deletions

diff --git a/core/subsurface-qt/SettingsObjectWrapper.cpp b/core/subsurface-qt/SettingsObjectWrapper.cpp
index 3085216c7..da2a86a68 100644
--- a/core/subsurface-qt/SettingsObjectWrapper.cpp
+++ b/core/subsurface-qt/SettingsObjectWrapper.cpp
@@ -1474,6 +1474,21 @@ bool GeneralSettingsObjectWrapper::autoRecalculateThumbnails() const
 	return prefs.auto_recalculate_thumbnails;
 }
 
+bool GeneralSettingsObjectWrapper::extractVideoThumbnails() const
+{
+	return prefs.extract_video_thumbnails;
+}
+
+int GeneralSettingsObjectWrapper::extractVideoThumbnailsPosition() const
+{
+	return prefs.extract_video_thumbnails_position;
+}
+
+QString GeneralSettingsObjectWrapper::ffmpegExecutable() const
+{
+	return prefs.ffmpeg_executable;
+}
+
 void GeneralSettingsObjectWrapper::setDefaultFilename(const QString& value)
 {
 	if (value == prefs.default_filename)
@@ -1579,6 +1594,43 @@ void GeneralSettingsObjectWrapper::setAutoRecalculateThumbnails(bool value)
 	emit autoRecalculateThumbnailsChanged(value);
 }
 
+void GeneralSettingsObjectWrapper::setExtractVideoThumbnails(bool value)
+{
+	if (value == prefs.extract_video_thumbnails)
+		return;
+
+	QSettings s;
+	s.beginGroup(group);
+	s.setValue("extract_video_thumbnails", value);
+	prefs.extract_video_thumbnails = value;
+	emit extractVideoThumbnailsChanged(value);
+}
+
+void GeneralSettingsObjectWrapper::setExtractVideoThumbnailsPosition(int value)
+{
+	if (value == prefs.extract_video_thumbnails_position)
+		return;
+
+	QSettings s;
+	s.beginGroup(group);
+	s.setValue("extract_video_thumbnails_position", value);
+	prefs.extract_video_thumbnails_position = value;
+	emit extractVideoThumbnailsPositionChanged(value);
+}
+
+void GeneralSettingsObjectWrapper::setFfmpegExecutable(const QString &value)
+{
+	if (value == prefs.ffmpeg_executable)
+		return;
+
+	QSettings s;
+	s.beginGroup(group);
+	s.setValue("ffmpeg_executable", value);
+	free((void *)prefs.ffmpeg_executable);
+	prefs.ffmpeg_executable = copy_qstring(value);
+	emit ffmpegExecutableChanged(value);
+}
+
 LanguageSettingsObjectWrapper::LanguageSettingsObjectWrapper(QObject *parent) :
 	QObject(parent)
 {