Video Playing

CVideoPlayerUtility provides a simple interface to open, play and obtain information from sampled video data. The video data can supplied either in a file, a descriptor or a URL.

For the purposes of this description, the playing process has been broken down into the following sections.

• Opening - describes the options available for opening video clips after the CVideoPlayerUtility object has been instantiated.

• Configuration - describes the various configuration settings such as volume and balance settings that can be queried or set.

• Plug-in Control - describes the information and commands that can be sent to or retrieved from plug-in controllers.

• Meta data control - describes the controls available for meta data manipulation.

• Playing - describes the controls available for playing video clips.

In the same way that CMdaAudioPlayerUtility provides methods for playing more than one audio file within a single instance, CVideoPlayerUtility provides methods to play multiple video clips within a single instance. A noticeable difference however, is that video clips cannot be opened during instantiation of the CVideoPlayerUtility object. Instead, all video clips must be opened using one of the open methods listed below after the player object has been created.

The following open methods are provided:

• Open statements for opening video clips after the player object has been created.

  OpenFileL(const TDesC& aFileName, TUid aControllerUid=KNullUid);

OpenDesL(const TDesC8& aDescriptor, TUid aControllerUid=KNullUid);

OpenUrlL(const TDesC& aUrl, TInt aIapId = KUseDefaultIap, const TDesC8& aMimeType=KNullDesC8, TUid aControllerUid=KNullUid);

• Open statements for opening and automatically playing video clips after the player object has been created.

  OpenAndPlayFileL(const TDesC& aFileName, TUid aControllerUid=KNullUid);

OpenAndPlayDesL(const TDesC8& aDescriptor, TUid aControllerUid=KNullUid);

OpenAndPlayUrlL(const TDesC& aUrl, TInt aIapId = KUseDefaultIap,  const TDesC8& aMimeType=KNullDesC8, TUid aControllerUid=KNullUid);

As soon as the open method has completed, successfully or otherwise, the callback function MVideoPlayerUtilityObserver::MvpuoOpenComplete() is called.

If a video clip is already open and playing, use Stop() followed by Close() to unload the video clip before specifying new video data to open.

Following the opening of the video clip, configuration adjustments can be made using the methods described below.

The configuration related methods are:

• General - covers the setting and reporting of playback priorities in relation to other applications that may be running, the detection of audio tracks within video clips, the detection of frame sizes and the setting of the display window. The specific methods are:

  • SetPriorityL() - sets the priority of the video/audio device which is used to arbitrate between multiple objects trying to access a controller.

  • PriorityL() - get the priority setting of the video/audio device.

  • AudioEnabledL() - determines whether an audio track is present within the video clip.

  • VideoFrameSizeL() - get the current frame size of the video clip.

  • SetDisplayWindowL() - set the display window to use when playing back the video clip.

• MIME type and codecs - covers the reporting of MIME type and codecs for video and audio data that is already open.

  • The MIME type of the video clip currently open can be retrieved using VideoFormatMimeType().

  • The codecs used by the video clip and possible audio track can be retrieved using VideoTypeL() and AudioTypeL() respectively.

  Note: the presence of an audio track within a video clip can be determined using AudioEnabledL().

• Bit and frame rates - covers the reporting of the bit and frame rate settings for video clips and possible audio tracks.

  • The bit rate of the video data can be retrieved using VideoBitRateL().

  • The bit rate of a possible audio track can be retrieved using AudioBitRateL().

  • The video frame rate in frames per second can be retrieved using VideoFrameRateL().

  Note: the presence of an audio track within a video clip can be determined using AudioEnabledL().

• Volume and gain - covers the reporting and setting of the volume levels for audio tracks belonging to video clips. The methods for controlling volume settings for playback are Volume(), SetVolumeL() and MaxVolume().

• Balance - covers the reporting and setting of the audio playback balance settings (if an audio track exists within the video clip).

  • The balance of a possible audio track can be set using SetBalanceL().

  • The balance setting of a possible audio track can be retrieved using Balance().

You can govern the relationship with a video plug-n in various ways:

• ControllerImplementationInformationL() - allows applications to query implementation information about the controller plugin in use.

• CustomCommandSync() - allows applications to send custom commands to controller plugins.

• RegisterForVideoLoadingNotification() - registers to receive notifications of video clip loading/rebuffering.

• GetVideoLoadingProgressL() - gets the progress of video clip loading/rebuffering.

Some video formats enable the use of meta data, enabling the player of a clip to retrieve information that is held within the clip itself. This meta data is usually used to store information such as copyright information, creator, creation date and so on.

CVideoPlayerUtility provides two meta data methods that enable you to:

• Get the number of meta data entries in a clip withNumberOfMetaDataEntriesL().

• Retrieve a specific meta data entry within a clip with MetaDataEntryL().

Note: it is not possible to set meta data using this class. If you need to set meta data, use CVideoRecorderUtility instead.

This class is intended for playing video clips only. As with CMdaAudioPlayerUtility, the CVideoPlayerUtility is capable of playing more than one clip within the same instance of the object.

The play related methods are:

• Play() - start playback of video data from the current position. When playing of the video sample is complete, successfully or otherwise, the callback function MVideoPlayerUtilityObserver::MvpuoPlayComplete() is called.

  You can also specify a start and endpoint in the videofile to be played using Play(const TTimeIntervalMicroSeconds& aStartPoint, const TTimeIntervalMicroSeconds& aEndPoint).

• PauseL() enables you to pause playback; the position within the video clip is maintained in case a subsequent Play() is issued.

• Stop() stops playback of the video sample as soon as is possible and calls the callback function MVideoPlayerUtilityObserver::MvpuoPlayComplete(). If playback is already complete, this function has no effect.

• Close() closes all related controllers.

• DurationL() - determine the duration of the video clip in microseconds.

• PositionL() and SetPositionL() retrieves or sets the current playing position within the video clip.

• RegisterForVideoLoadingNotification() - activate callbacks that report on video rebuffering. The callback used for this mechanism are, MVideoLoadingObserver::MvloLoadingStarted() and MVideoLoadingObserver::MvloLoadingComplete().

• GetFrame() - uses the MVideoPlayerUtilityObserver::MvpuoFrameReady() callback to return a bitmap of the frame currently being played.

• RefreshFrameL(); - re-draw the current frame.

• Multi Media Framework Client Overview - general overview of the various components of the MMF Client API and the functionality they provide.

• Audio Recording, Conversion and Playing - advanced audio file manipulation features; specifically, the ability to record, convert and playback sound clips as well as to manipulate meta data.

  • Audio Recording - introduction to the audio recording class.

  • Audio Conversion - introduction to the audio conversion class.

  • Audio Playing - introduction to the audio playing class.

• Audio Streaming - the interface to streaming sampled audio.

• Audio Tone Player - a simple interface for tone generation (synthesized sounds) that is supported on all audio-capable devices.

• Video Recording and Playing - video manipulation features; specifically, the ability to record and playback video clips as well as to manipulate meta data.

  • Video Recording - introduction to the video recording class.

  • Video Playing - introduction to the video playing class.