StelVideoMgr provides a scriptable way to show videos embedded in the screen. More...

#include <StelVideoMgr.hpp>

Public Slots
void	init () override

void	update (double deltaTime) override
	Update the module with respect to the time. More...

void	loadVideo (const QString &filename, const QString &id, const float x, const float y, const bool show, const float alpha)
	load a video from filename, assign an id for it for later reference. More...

void	playVideo (const QString &id, const bool keepVisibleAtEnd=false)
	play video from current position. If keepLastFrame is true, video pauses at last frame.

void	playVideoPopout (const QString &id, float fromX, float fromY, float atCenterX, float atCenterY, float finalSizeX, float finalSizeY, float popupDuration, bool frozenInTransition)
	Play a video which has previously been loaded with loadVideo() with a complex effect. More...

void	pauseVideo (const QString &id)
	Pause video, keep it visible on-screen. More...

void	stopVideo (const QString &id)
	Stop playing, resets video and hides video output window.

void	dropVideo (const QString &id)
	Unload video from memory.

void	seekVideo (const QString &id, const qint64 ms, bool pause=false)
	Seek a position in video id. More...

void	setVideoXY (const QString &id, const float x, const float y, const bool relative=false)
	move upper left corner of video id to x, y. More...

void	setVideoAlpha (const QString &id, const float alpha)
	sets opacity More...

void	resizeVideo (const QString &id, float w=-1.0f, float h=-1.0f)
	set video size to width w and height h. More...

void	showVideo (const QString &id, const bool show)
	show or hide video player More...

qint64	getVideoDuration (const QString &id) const
	returns duration (in milliseconds) of loaded video. More...

qint64	getVideoPosition (const QString &id) const
	returns current position (in milliseconds) of loaded video. More...

QSize	getVideoResolution (const QString &id) const
	returns resolution (in pixels) of loaded video. Returned value may be invalid before video has been fully loaded.

int	getVideoWidth (const QString &id) const
	returns native width (in pixels) of loaded video, or -1 in case of trouble.

int	getVideoHeight (const QString &id) const
	returns native height (in pixels) of loaded video, or -1 in case of trouble.

void	muteVideo (const QString &id, bool muteVideo=true)
	set mute state of video player More...

void	setVideoVolume (const QString &id, int newVolume)
	set volume for video. Valid values are 0..100, values outside this range will be clamped.

int	getVideoVolume (const QString &id) const
	return currently set volume (0..100) of media player, or -1 in case of some error.

bool	isVideoPlaying (const QString &id) const
	returns whether video is currently playing. More...

Public Member Functions
	StelVideoMgr (bool withAudio)
	Constructor. More...

Public Member Functions inherited from StelModule
	StelModule ()
	Constructor. Every derived class MUST call setObjectName(className) in its constructor.

virtual void	init ()=0
	Initialize itself. More...

virtual void	deinit ()
	Called before the module will be deleted, and before the OpenGL context is suppressed. More...

virtual QSettings *	getSettings ()
	Return module-specific settings. More...

virtual void	draw (StelCore *core)
	Execute all the drawing functions for this module. More...

virtual void	update (double deltaTime)
	Update the module with respect to the time. More...

virtual QString	getModuleVersion () const
	Get the version of the module, default is stellarium main version.

virtual QString	getAuthorName () const
	Get the name of the module author.

virtual QString	getAuthorEmail () const
	Get the email address of the module author.

virtual void	handleMouseClicks (class QMouseEvent *)
	Handle mouse clicks. More...

virtual void	handleMouseWheel (class QWheelEvent *)
	Handle mouse wheel. More...

virtual bool	handleMouseMoves (int x, int y, Qt::MouseButtons b)
	Handle mouse moves. More...

virtual void	handleKeys (class QKeyEvent *e)
	Handle key events. More...

virtual bool	handlePinch (qreal scale, bool started)
	Handle pinch gesture events. More...

virtual double	getCallOrder (StelModuleActionName actionName) const
	Return the value defining the order of call for the given action For example if stars.callOrder[ActionDraw] == 10 and constellation.callOrder[ActionDraw] == 11, the stars module will be drawn before the constellations. More...

virtual bool	configureGui (bool show=true)
	Detect or show the configuration GUI elements for the module. More...

Additional Inherited Members
Public Types inherited from StelModule
enum	StelModuleSelectAction { AddToSelection , ReplaceSelection , RemoveFromSelection }
	Enum used when selecting objects to define whether to add to, replace, or remove from the existing selection list. More...

enum	StelModuleActionName { ActionDraw , ActionUpdate , ActionHandleMouseClicks , ActionHandleMouseMoves , ActionHandleKeys }
	Define the possible action for which an order is defined. More...

Protected Member Functions inherited from StelModule
class StelAction *	addAction (const QString &id, const QString &groupId, const QString &text, QObject target, const char slot, const QString &shortcut="", const QString &altShortcut="")
	convenience methods to add an action (call to slot) to the StelActionMgr object. More...

class StelAction *	addAction (const QString &id, const QString &groupId, const QString &text, const char *slot, const QString &shortcut="", const QString &altShortcut="")
	convenience methods to add an action (call to own slot) to the StelActionMgr object. More...

StelAction *	addAction (const QString &id, const QString &groupId, const QString &text, QObject *contextObject, std::function< void()> lambda, const QString &shortcut="", const QString &altShortcut="")
	convenience methods to add an action (call to Lambda functor) to the StelActionMgr object. More...

Detailed Description

StelVideoMgr provides a scriptable way to show videos embedded in the screen.

After experimental support with Qt4/Phonon library, this feature is available with native classes from Qt5 and Qt6. The latter seems much better. Videos can be scaled, paused, placed and relocated (shifted) on screen. Setting opacity seems not to do much in Qt5 unless setting it to zero, the video is then simply invisible. On Qt6 it mixes nicely. Therefore smooth fading in/out has not yet been developed or setting a semitransparent overlay does not work, but there is now an intro/end animation available: zooming out from a pixel position to a player frame position, and returning to that spot close to end of video playback.

However, support for multimedia content depends on the operating system, installed codecs, and completeness of the QtMultimedia system support, so some features or video formats may not work for you (test video and re-code it if necessary).

Linux notes

The listed functions have been tested and work on Ubuntu 15.04 with Qt5.4 with NVidia 9800M and Intel Core-i3/HD5500. You need to install GStreamer plugins. Most critical seems to be gstreamer0.10-ffmpeg from https://launchpad.net/~mc3man/+archive/ubuntu/gstffmpeg-keep, then it plays

MP4 (h264)
Apple MOV(Sorenson)
WMV.
Some type of AVI failed

In 2022 and with Qt6 (https://doc.qt.io/qt-6/videooverview.html) Qt requires:

gstreamer1.0-plugins-base
gstreamer1.0-plugins-good
gstreamer1.0-pulseaudio
For a Linux desktop target, it is strongly recommended to have gstreamer1.0-libav for good codec coverage and gstreamer1.0-vaapi to get hardware acceleration.

Windows notes

Qt5

According to https://wiki.qt.io/Qt_Multimedia, MinGW is limited to the decaying DirectShow platform plugin. The WMF platform plugin requires Visual Studio, so building with MSVC should provide better results. Some signals are not triggered under Windows, so we cannot use them, globally. There is partial success with MP4 files on MinGW, but also these are rendered badly. Often just shows an error on Windows/MinGW: DirectShowPlayerService::doRender: Unresolved error code 80040154 (number may differ, also seen: 80040228. Where is a list?) The formats tested on Windows are:

MP4 (h264; OK)
WMV (OK, but jumping to different locations via seekVideo() seems not to work properly)
MOV (mp4v codec, very jerky, basically unusable)
AVI (DIVX MP4 codec, same bad issues as MOV)
OGV (invalid media)
WEBM (invalid media)

Update 2022: Seems to work with Qt5.12 and later. Does not show frame on Qt5.9. It also does not work in WSL/Ubuntu 20.04LTS/Qt5.12

Qt6

Qt's API has changed, but much to the better. It finally seems to work as advertised. Even alpha transparency of the frame works.

Mac OS X Notes

Observations on macOS12.5: Works with Qt6, does not work with Qt5.

QtMultimedia is a bit tricky to use: There seems to be no way to load a media file to analyze resolution or duration before starting its replay. This means, configuring player frames either require absolute frame coordinates, or triggering necessary configuration steps only after replay has started. We opted for the latter solution because it allows scaled but undistorted video frames which may also take current screen resolution into account.

Failed to start video surface due to main thread blocked.

Failed to start video surface

and non-appearing video frame, this seems to be https://bugreports.qt.io/browse/QTBUG-39567. This occurred on an Intel NUC5i3 with SSD, so loading the file should not be much of an issue.

To help in debugging scripts, this module can be quite verbose in the logfile if Stellarium is called with the command-line argument "--verbose".

Constructor & Destructor Documentation

◆ StelVideoMgr()

StelVideoMgr::StelVideoMgr ( bool withAudio )

Constructor.

Parameters

withAudio usually true to allow audio output.

Member Function Documentation

◆ getVideoDuration

qint64 StelVideoMgr::getVideoDuration ( const QString & id ) const

slot

returns duration (in milliseconds) of loaded video.

This may return valid result only after playVideo() or pauseVideo() have been called. Returns -1 if video has not been analyzed yet. (loaded, but not started).

◆ getVideoPosition

qint64 StelVideoMgr::getVideoPosition ( const QString & id ) const

slot

returns current position (in milliseconds) of loaded video.

This may return valid result only after playVideo() or pauseVideo() have been called. Returns -1 if video has not been analyzed yet. (loaded, but not started).

◆ isVideoPlaying

bool StelVideoMgr::isVideoPlaying ( const QString & id ) const

slot

returns whether video is currently playing.

Parameters

id	name assigned during loadVideo().

Note: If video is not found, also returns false.

◆ loadVideo

void StelVideoMgr::loadVideo	(	const QString &	filename,
		const QString &	id,
		const float	x,
		const float	y,
		const bool	show,
		const float	alpha
	)

slot

load a video from filename, assign an id for it for later reference.

If id is already in use, replace it. Prepare replay at upper-left corner x/ y in native resolution, decide whether to show (play) the video already, and set opacity alpha. If you want non-native resolution, load with show set to false, and use resizeVideo() and showVideo().

◆ muteVideo

void StelVideoMgr::muteVideo	(	const QString &	id,
		bool	muteVideo = `true`
	)

slot

set mute state of video player

Parameters

muteVideo true to silence the video, false to hear audio.

◆ pauseVideo

void StelVideoMgr::pauseVideo ( const QString & id )

slot

Pause video, keep it visible on-screen.

Calling playVideo() continues replay, calling seekVideo() can move to a different position.

◆ playVideoPopout

void StelVideoMgr::playVideoPopout	(	const QString &	id,
		float	fromX,
		float	fromY,
		float	atCenterX,
		float	atCenterY,
		float	finalSizeX,
		float	finalSizeY,
		float	popupDuration,
		bool	frozenInTransition
	)

slot

Play a video which has previously been loaded with loadVideo() with a complex effect.

The video appears to pop out from fromX/ fromY, grows within popupDuration to size finalSizeX/ finalSizeY, and shrinks back towards fromX/ fromY at the end during popdownDuration.

Parameters

id	the identifier used when loadVideo was called
fromX	X position of starting point, counted from left of window. May be absolute (if >1) or relative (0<X<1)
fromY	Y position of starting point, counted from top of window. May be absolute (if >1) or relative (0<Y<1)
atCenterX	X position of center of final video frame, counted from left of window. May be absolute (if >1) or relative (0<X<1)
atCenterY	Y position of center of final video frame, counted from top of window. May be absolute (if >1) or relative (0<Y<1)
finalSizeX	X size of final video frame. May be absolute (if >1) or relative to window size (0<X<1). If -1, scale proportional from finalSizeY.
finalSizeY	Y size of final video frame. May be absolute (if >1) or relative to window size (0<Y<1). If -1, scale proportional from finalSizeX.
popupDuration	duration of growing (start) / shrinking (end) transitions (seconds)
frozenInTransition	true if video should be paused during growing/shrinking transition.

◆ resizeVideo

void StelVideoMgr::resizeVideo	(	const QString &	id,
		float	w = `-1.0f`,
		float	h = `-1.0f`
	)

slot

set video size to width w and height h.

Use w=-1 or h=-1 for autoscale from the other dimension, or use w=h=-1 for native size of video. if w or h are <=1, the size is relative to screen dimensions. This should be the preferred use, because it allows the development of device-independent scripts. When native resolution is unknown at the time you call this, it will be evaluated at the next update() after resolution becomes known. Autoscaling uses viewport dimensions at the time of calling, so resizing the Stellarium window will not resize the video frame during replay.

◆ seekVideo

void StelVideoMgr::seekVideo	(	const QString &	id,
		const qint64	ms,
		bool	pause = `false`
	)

slot

Seek a position in video id.

Pause the video playing if pause=true.

Note: This may not work if video has not been fully loaded. Better wait a second before proceeding after loadVideo(), and call seekVideo(., ., false); pauseVideo(.);

◆ setVideoAlpha

void StelVideoMgr::setVideoAlpha	(	const QString &	id,
		const float	alpha
	)

slot

sets opacity

Parameters

alpha opacity for the video (0=transparent, ... 1=fully opaque).

Note: if alpha is 0, also showVideo(id, true) cannot show the video.

◆ setVideoXY

void StelVideoMgr::setVideoXY	(	const QString &	id,
		const float	x,
		const float	y,
		const bool	relative = `false`
	)

slot

move upper left corner of video id to x, y.

If x or y are <1, this is relative to screen size!

◆ showVideo

void StelVideoMgr::showVideo	(	const QString &	id,
		const bool	show
	)

slot

show or hide video player

Parameters

id	name given during loadVideo()
show	true to show, false to hide

◆ update

void StelVideoMgr::update ( double deltaTime )

overrideslot

Update the module with respect to the time.

This allows the special effects in playVideoPopout(), and may evaluate things like video resolution when they become available.

Parameters

deltaTime the time increment in second since last call.

Public Slots

Public Member Functions

Additional Inherited Members

Detailed Description

Linux notes

Windows notes

Qt5

Qt6

Mac OS X Notes

Constructor & Destructor Documentation

◆ StelVideoMgr()

Member Function Documentation

◆ getVideoDuration

◆ getVideoPosition

◆ isVideoPlaying

◆ loadVideo

◆ muteVideo

◆ pauseVideo

◆ playVideoPopout

◆ resizeVideo

◆ seekVideo

◆ setVideoAlpha

◆ setVideoXY

◆ showVideo

◆ update