mmhais/videohai/devvideo/inc/devvideoplayratecustominterface.h
changeset 0 40261b775718
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/mmhais/videohai/devvideo/inc/devvideoplayratecustominterface.h	Tue Feb 02 01:56:55 2010 +0200
@@ -0,0 +1,190 @@
+// Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).
+// All rights reserved.
+// This component and the accompanying materials are made available
+// under the terms of "Eclipse Public License v1.0"
+// which accompanies this distribution, and is available
+// at the URL "http://www.eclipse.org/legal/epl-v10.html".
+//
+// Initial Contributors:
+// Nokia Corporation - initial contribution.
+//
+// Contributors:
+//
+// Description:
+//
+
+#ifndef DEVVIDEOPLAYRATECUSTOMINTERFACE_H
+#define DEVVIDEOPLAYRATECUSTOMINTERFACE_H
+
+#include <mmf/common/mmfvideo.h>
+#ifdef SYMBIAN_ENABLE_SPLIT_HEADERS
+#include <mmf/common/mmfvideoenums.h>
+#endif
+
+/**
+MMmfVideoPlayRateControl interface UID.
+
+@publishedPartner
+@released
+*/
+const TUid KUidMmfVideoPlayRateControl = { 0x10285D3C };
+
+/**
+Video play rate observer that is used with the MMmfVideoPlayRateControl 
+custom interface. Controllers or other DevVideo clients using that custom
+interface must implement this observer interface.
+
+@publishedPartner
+@released
+*/
+class MMmfVideoPlayRateObserver
+	{
+public:
+	/**
+	Indicates that a step frame request has been completed. This callback is a 
+	response to an MmvprcStepFrameL() call.
+
+	@param aTimestamp The timestamp for the frame that was actually rendered as
+			a result of the frame step operation
+	*/
+	virtual void MmvproStepFrameComplete(TTimeIntervalMicroSeconds aTimestamp) = 0;
+
+	/**
+	Requests that the controller should only pass key frames to DevVideo.
+	The key frame mode will be in operation until normal playback is resumed.
+	*/
+	virtual void MmvproKeyFrameModeRequest() = 0;
+};
+
+/**
+Video play rate control custom interface. Controllers or other DevVideo clients
+can use this interface for trick play control.
+
+Note that both decoders and post-processors can implement this interface. Clients 
+must query both the decoder and the post-processor (if in use) for the custom 
+interface, and call methods on both if they implement the interface. At least 
+the rendering media device (typically the post-processor) must implement this 
+interface for playback rate control to be available.
+
+Additionally, the timestamp returned from the clock source must reflect the 
+playback speed. For example, for 200% fast forward, the timestamps returned must 
+increase at two times the normal speed.
+
+@publishedPartner
+@released
+*/
+class MMmfVideoPlayRateControl
+	{
+public:
+	/**
+	Queries the current video playback rate capabilities. The capabilities
+	describe whether fast forward, reverse playback, slow motion, or
+	step backward or forward is possible. The capabilities may depend on
+	the video decoder / post processor implementation and the video stream. 
+
+	If an error occurs, this function leaves with any of the system wide error codes.
+
+	@param aCapabilities Playback rate capabilities
+	*/
+	virtual void MmvprcGetPlayRateCapabilitiesL(TVideoPlayRateCapabilities& aCapabilities) = 0;
+
+	/**
+	Set video playback rate relative to the normal video stream speed.
+	This method can be used for fast forward, rewind, and slow-motion
+	playback, depending on the capabilities of the underlying video 
+	decoder / post processor implementation and the characteristics of 
+	the video stream. Rate set in this call will take effect immediately. 
+	Use	MmvprcGetPlayRateCapabilitiesL() to determine what playback modes 
+	are	available.
+
+	Note that due to performance reasons, it may not be possible to perform
+	fast forward or rewind at the requested speed. If that happens, the
+	video decoder / post processor will use the nearest available rate. This is not
+	considered an error and the method will not leave. DevVideo clients can query
+	rate in effect by calling MmvprcPlayRateL().
+
+	The default playback rate is 100.
+	Play rate is persistent across stop start calls on DevVideo. 
+
+	If an error occurs, this function leaves with any of the system wide error codes.
+	Common error codes are listed below.
+
+	@param aRate Playback rate as a percentage relative to the
+                 normal video stream speed. Use 100 for normal-speed
+                 forward playback and negative value for reverse. Values above
+                 100 and below 0 correspond to fast forward and
+                 rewind respectively, while values 1 to 100 represent
+                 slow-motioned playback.
+
+	@pre Playback has been started, but may be paused.
+
+	@see MMmfVideoPlayRateControl::MmvprcGetPlayRateCapabilitiesL()
+
+	@leave KErrNotSupported The requested playback rate is not supported.
+	@leave KErrNotReady Playback has not yet been started
+	*/
+	virtual void MmvprcSetPlayRateL(const TInt aRate) = 0;
+
+	/**
+	Returns the current playback rate. If setting play rate is
+	not supported or rate is not set this will return default play rate
+	100 corresponding to normal playback.
+
+	If implementation is not supporting the rate set with MmvprcSetPlayRateL
+	it will default to the nearest rate. In this case this API will return
+	the value it has defaulted to.
+
+	If an error occurs, this function leaves with any of the system
+	wide error codes. Common error codes are listed below.
+
+	@return The current playback rate as a percentage relative to the
+        	normal video stream speed.
+
+	@pre Playback has been started, but may be paused.
+
+	@see MMmfVideoPlayRateControl::MmvprcGetPlayRateCapabilitiesL()
+	@see MMmfVideoPlayRateControl::MmvprcSetPlayRateL()
+
+	@leave KErrNotReady Playback has not yet been started
+	*/
+	virtual TInt MmvprcPlayRateL() = 0;
+
+	/**
+	Steps the current video playback position forward or backward by a
+	number of frames. Frame step is only available when playback is paused.
+
+	Support for frame stepping may depend on the underlying video decoder / 
+	post processor implementation and the video stream open. Use 
+	MmvprcGetPlayRateCapabilitiesL() to query if frame step is currently possible. 
+
+	Implementations may not be able to step exactly the number of frames
+	requested, especially when stepping backwards. If this happens, the
+	video decoder / post processor will step to a frame close to the one requested. 
+	This is	not considered an error.
+
+	If an error occurs, this function leaves with any of the system wide error codes.
+	Common error codes are listed below.
+
+	@param aStep The number of frames to step. Use positive values for
+             stepping forward and negative values for stepping back.
+
+	@pre Playback has been started and is currently paused. That means this API 
+			can be called only in paused state.
+
+	@see MMmfVideoPlayRateControl::MmvprcGetPlayRateCapabilitiesL()
+
+	@leave KErrNotSupported Frame step is not supported. Note that some
+         	implementations may support step forward but not step backward.
+	@leave KErrNotReady Playback has not yet been started or is not in paused state.
+	*/
+	virtual void MmvprcStepFrameL(const TInt aStep) = 0;
+
+	/**
+	Sets a play rate observer
+
+	@param aObserver Play rate observer
+	*/
+	virtual void MmvprcSetObserver(MMmfVideoPlayRateObserver& aObserver) = 0;
+	};
+
+#endif // DEVVIDEOPLAYRATECUSTOMINTERFACE_H