1 // Copyright (c) 2008-2009 Nokia Corporation and/or its subsidiary(-ies).
2 // All rights reserved.
3 // This component and the accompanying materials are made available
4 // under the terms of "Eclipse Public License v1.0"
5 // which accompanies this distribution, and is available
6 // at the URL "http://www.eclipse.org/legal/epl-v10.html".
8 // Initial Contributors:
9 // Nokia Corporation - initial contribution.
16 #ifndef DEVVIDEOPLAYRATECUSTOMINTERFACE_H
17 #define DEVVIDEOPLAYRATECUSTOMINTERFACE_H
19 #include <mmf/common/mmfvideo.h>
20 #ifdef SYMBIAN_ENABLE_SPLIT_HEADERS
21 #include <mmf/common/mmfvideoenums.h>
25 MMmfVideoPlayRateControl interface UID.
30 const TUid KUidMmfVideoPlayRateControl = { 0x10285D3C };
33 Video play rate observer that is used with the MMmfVideoPlayRateControl
34 custom interface. Controllers or other DevVideo clients using that custom
35 interface must implement this observer interface.
40 class MMmfVideoPlayRateObserver
44 Indicates that a step frame request has been completed. This callback is a
45 response to an MmvprcStepFrameL() call.
47 @param aTimestamp The timestamp for the frame that was actually rendered as
48 a result of the frame step operation
50 virtual void MmvproStepFrameComplete(TTimeIntervalMicroSeconds aTimestamp) = 0;
53 Requests that the controller should only pass key frames to DevVideo.
54 The key frame mode will be in operation until normal playback is resumed.
56 virtual void MmvproKeyFrameModeRequest() = 0;
60 Video play rate control custom interface. Controllers or other DevVideo clients
61 can use this interface for trick play control.
63 Note that both decoders and post-processors can implement this interface. Clients
64 must query both the decoder and the post-processor (if in use) for the custom
65 interface, and call methods on both if they implement the interface. At least
66 the rendering media device (typically the post-processor) must implement this
67 interface for playback rate control to be available.
69 Additionally, the timestamp returned from the clock source must reflect the
70 playback speed. For example, for 200% fast forward, the timestamps returned must
71 increase at two times the normal speed.
76 class MMmfVideoPlayRateControl
80 Queries the current video playback rate capabilities. The capabilities
81 describe whether fast forward, reverse playback, slow motion, or
82 step backward or forward is possible. The capabilities may depend on
83 the video decoder / post processor implementation and the video stream.
85 If an error occurs, this function leaves with any of the system wide error codes.
87 @param aCapabilities Playback rate capabilities
89 virtual void MmvprcGetPlayRateCapabilitiesL(TVideoPlayRateCapabilities& aCapabilities) = 0;
92 Set video playback rate relative to the normal video stream speed.
93 This method can be used for fast forward, rewind, and slow-motion
94 playback, depending on the capabilities of the underlying video
95 decoder / post processor implementation and the characteristics of
96 the video stream. Rate set in this call will take effect immediately.
97 Use MmvprcGetPlayRateCapabilitiesL() to determine what playback modes
100 Note that due to performance reasons, it may not be possible to perform
101 fast forward or rewind at the requested speed. If that happens, the
102 video decoder / post processor will use the nearest available rate. This is not
103 considered an error and the method will not leave. DevVideo clients can query
104 rate in effect by calling MmvprcPlayRateL().
106 The default playback rate is 100.
107 Play rate is persistent across stop start calls on DevVideo.
109 If an error occurs, this function leaves with any of the system wide error codes.
110 Common error codes are listed below.
112 @param aRate Playback rate as a percentage relative to the
113 normal video stream speed. Use 100 for normal-speed
114 forward playback and negative value for reverse. Values above
115 100 and below 0 correspond to fast forward and
116 rewind respectively, while values 1 to 100 represent
117 slow-motioned playback.
119 @pre Playback has been started, but may be paused.
121 @see MMmfVideoPlayRateControl::MmvprcGetPlayRateCapabilitiesL()
123 @leave KErrNotSupported The requested playback rate is not supported.
124 @leave KErrNotReady Playback has not yet been started
126 virtual void MmvprcSetPlayRateL(const TInt aRate) = 0;
129 Returns the current playback rate. If setting play rate is
130 not supported or rate is not set this will return default play rate
131 100 corresponding to normal playback.
133 If implementation is not supporting the rate set with MmvprcSetPlayRateL
134 it will default to the nearest rate. In this case this API will return
135 the value it has defaulted to.
137 If an error occurs, this function leaves with any of the system
138 wide error codes. Common error codes are listed below.
140 @return The current playback rate as a percentage relative to the
141 normal video stream speed.
143 @pre Playback has been started, but may be paused.
145 @see MMmfVideoPlayRateControl::MmvprcGetPlayRateCapabilitiesL()
146 @see MMmfVideoPlayRateControl::MmvprcSetPlayRateL()
148 @leave KErrNotReady Playback has not yet been started
150 virtual TInt MmvprcPlayRateL() = 0;
153 Steps the current video playback position forward or backward by a
154 number of frames. Frame step is only available when playback is paused.
156 Support for frame stepping may depend on the underlying video decoder /
157 post processor implementation and the video stream open. Use
158 MmvprcGetPlayRateCapabilitiesL() to query if frame step is currently possible.
160 Implementations may not be able to step exactly the number of frames
161 requested, especially when stepping backwards. If this happens, the
162 video decoder / post processor will step to a frame close to the one requested.
163 This is not considered an error.
165 If an error occurs, this function leaves with any of the system wide error codes.
166 Common error codes are listed below.
168 @param aStep The number of frames to step. Use positive values for
169 stepping forward and negative values for stepping back.
171 @pre Playback has been started and is currently paused. That means this API
172 can be called only in paused state.
174 @see MMmfVideoPlayRateControl::MmvprcGetPlayRateCapabilitiesL()
176 @leave KErrNotSupported Frame step is not supported. Note that some
177 implementations may support step forward but not step backward.
178 @leave KErrNotReady Playback has not yet been started or is not in paused state.
180 virtual void MmvprcStepFrameL(const TInt aStep) = 0;
183 Sets a play rate observer
185 @param aObserver Play rate observer
187 virtual void MmvprcSetObserver(MMmfVideoPlayRateObserver& aObserver) = 0;
190 #endif // DEVVIDEOPLAYRATECUSTOMINTERFACE_H