api/include/evcode.h

//------------------------------------------------------------------------------
// File: EvCode.h
//
// Desc: List of standard Quartz event codes and the expected params.
//
// Copyright (c) 1992 - 2000, Microsoft Corporation.  All rights reserved.
//------------------------------------------------------------------------------


// Event codes are broken into two groups
//   -- system event codes
//   -- extension event codes
// All system event codes are below EC_USER

#define EC_SYSTEMBASE                       0x00
#define EC_USER                             0x8000

// System-defined event codes
// ==========================
//
// There are three types of system-defined event codes:
//
// 1.  Those which are always passed through to the application
//     (To be collected by calls to GetEvent or within WaitForCompletion.)
//     (e.g. EC_ERRORABORT, EC_USERABORT.)
//
// 2.  Those which are pure internal and will never be passed to
//     the application.  (e.g. EC_SHUTDOWN)
//
// 3.  Those which have default handling.  Default handing implies that
//     the event is not passed to the application.  However, default
//     handling may be canceled by calling
//     IMediaEvent::CancelDefaultHandling.  If the default handling is
//     cancelled in this way, then the message will be delivered to the
//     application and the application must action it appropriately.
//     Default handling can be restored by calling RestoreDefaultHandling.
//
// We will refer to these events as application, internal and defaulted
// events respectively.
//
// System-defined events may have interface pointers, BSTR's, etc passed
// as parameters.  It is therefore essential that, for any message
// retrieved using GetEvent, a matching call to FreeEventParams is made
// to ensure that relevant interfaces are released and storage freed.
// Failure to call FreeEventParams will result in memory leaks, if not
// worse.
//
// Filters sending these messages to the filter graph should not AddRef()
// any interfaces that they may pass as parameters.  The filter graph
// manager will AddRef them if required.  E.g. if the event is to be queued
// for the application or queued to a worker thread.

// Each event listed below is immediately followed by a parameter list
// detailing the types of the parameters associated with the message,
// and an indication of whether the message is an application, internal
// or defaulted message.  This is then followed by a short description.
// The use of "void" in the parameter list implies that the parameter is not
// used.  Such parameters should be zero.

// Other defined EC_ regions:
// DVD event codes           0x0100 - 0x0150 (dvdevcod.h)
// audio device event codes  0x0200 - 0x0250 (audevcod.h)
// WindowsMedia SDK-originated events 0x0251 - 0x0300 (see below)

#define EC_COMPLETE                         0x01
// ( HRESULT, void ) : defaulted (special)
// Signals the completed playback of a stream within the graph.  This message
// is sent by renderers when they receive end-of-stream.  The default handling
// of this message results in a _SINGLE_ EC_COMPLETE being sent to the
// application when ALL of the individual renderers have signaled EC_COMPLETE
// to the filter graph.  If the default handing is canceled, the application
// will see all of the individual EC_COMPLETEs.


#define EC_USERABORT                        0x02
// ( void, void ) : application
// In some sense, the user has requested that playback be terminated.
// This message is typically sent by renderers that render into a
// window if the user closes the window into which it was rendering.
// It is up to the application to decide if playback should actually
// be stopped.


#define EC_ERRORABORT                       0x03
// ( HRESULT, void ) : application
// Operation aborted because of error


#define EC_TIME                             0x04
// ( DWORD, DWORD ) : application
// The requested reference time occurred.  (This event is currently not used).
// lParam1 is low dword of ref time, lParam2 is high dword of reftime.


#define EC_REPAINT                          0x05
// ( IPin * (could be NULL), void ) : defaulted
// A repaint is required - lParam1 contains the (IPin *) that needs the data
// to be sent again. Default handling is: if the output pin which the IPin is
// attached  to supports the IMediaEventSink interface then it will be called
// with the EC_REPAINT first.  If that fails then normal repaint processing is
// done by the filter graph.


// Stream error notifications
#define EC_STREAM_ERROR_STOPPED             0x06
#define EC_STREAM_ERROR_STILLPLAYING        0x07
// ( HRESULT, DWORD ) : application
// lParam 1 is major code, lParam2 is minor code, either may be zero.


#define EC_ERROR_STILLPLAYING               0x08
// ( HRESULT, void ) : application
// The filter graph manager may issue Run's to the graph asynchronously.
// If such a Run fails, EC_ERROR_STILLPLAYING is issued to notify the
// application of the failure.  The state of the underlying filters
// at such a time will be indeterminate - they will all have been asked
// to run, but some are almost certainly not.


#define EC_PALETTE_CHANGED                  0x09
// ( void, void ) : application
// notify application that the video palette has changed


#define EC_VIDEO_SIZE_CHANGED               0x0A
// ( DWORD, void ) : application
// Sent by video renderers.
// Notifies the application that the native video size has changed.
// LOWORD of the DWORD is the new width, HIWORD is the new height.


#define EC_QUALITY_CHANGE                   0x0B
// ( void, void ) : application
// Notify application that playback degradation has occurred


#define EC_SHUTTING_DOWN                    0x0C
// ( void, void ) : internal
// This message is sent by the filter graph manager to any plug-in
// distributors which support IMediaEventSink to notify them that
// the filter graph is starting to shutdown.


#define EC_CLOCK_CHANGED                    0x0D
// ( void, void ) : application
// Notify application that the clock has changed.
// (i.e. SetSyncSource has been called on the filter graph and has been
// distributed successfully to the filters in the graph.)


#define EC_PAUSED                           0x0E
// ( HRESULT, void ) : application
// Notify application the previous pause request has completed


#define EC_OPENING_FILE                     0x10
#define EC_BUFFERING_DATA                   0x11
// ( BOOL, void ) : application
// lParam1 == 1   --> starting to open file or buffer data
// lParam1 == 0   --> not opening or buffering any more
// (This event does not appear to be used by ActiveMovie.)


#define EC_FULLSCREEN_LOST                  0x12
// ( void, IBaseFilter * ) : application
// Sent by full screen renderers when switched away from full screen.
// IBaseFilter may be NULL.


#define EC_ACTIVATE                         0x13
// ( BOOL, IBaseFilter * ) : internal
// Sent by video renderers when they lose or gain activation.
// lParam1 is set to 1 if gained or 0 if lost
// lParam2 is the IBaseFilter* for the filter that is sending the message
// Used for sound follows focus and full-screen switching


#define EC_NEED_RESTART                     0x14
// ( void, void ) : defaulted
// Sent by renderers when they regain a resource (e.g. audio renderer).
// Causes a restart by Pause/put_Current/Run (if running).


#define EC_WINDOW_DESTROYED                 0x15
// ( IBaseFilter *, void ) : internal
// Sent by video renderers when the window has been destroyed. Handled
// by the filter graph / distributor telling the resource manager.
// lParam1 is the IBaseFilter* of the filter whose window is being destroyed


#define EC_DISPLAY_CHANGED                  0x16
// ( IPin *, void ) : internal
// Sent by renderers when they detect a display change. the filter graph
// will arrange for the graph to be stopped and the pin send in lParam1
// to be reconnected. by being reconnected it allows a renderer to reset
// and connect with a more appropriate format for the new display mode
// lParam1 contains an (IPin *) that should be reconnected by the graph


#define EC_STARVATION                       0x17
// ( void, void ) : defaulted
// Sent by a filter when it detects starvation. Default handling (only when
// running) is for the graph to be paused until all filters enter the
// paused state and then run. Normally this would be sent by a parser or source
// filter when too little data is arriving.


#define EC_OLE_EVENT                        0x18
// ( BSTR, BSTR ) : application
// Sent by a filter to pass a text string to the application.
// Conventionally, the first string is a type, and the second a parameter.


#define EC_NOTIFY_WINDOW                    0x19
// ( HWND, void ) : internal
// Pass the window handle around during pin connection.

#define EC_STREAM_CONTROL_STOPPED           0x1A
// ( IPin * pSender, DWORD dwCookie )
// Notification that an earlier call to IAMStreamControl::StopAt
// has now take effect.  Calls to the method can be marked
// with a cookie which is passed back in the second parameter,
// allowing applications to easily tie together request
// and completion notifications.
//
// NB: IPin will point to the pin that actioned the Stop.  This
// may not be the pin that the StopAt was sent to.

#define EC_STREAM_CONTROL_STARTED           0x1B
// ( IPin * pSender, DWORD dwCookie )
// Notification that an earlier call to IAMStreamControl::StartAt
// has now take effect.  Calls to the method can be marked
// with a cookie which is passed back in the second parameter,
// allowing applications to easily tie together request
// and completion notifications.
//
// NB: IPin will point to the pin that actioned the Start.  This
// may not be the pin that the StartAt was sent to.

#define EC_END_OF_SEGMENT                   0x1C
//
// ( const REFERENCE_TIME *pStreamTimeAtEndOfSegment, DWORD dwSegmentNumber )
//
// pStreamTimeAtEndOfSegment
//     pointer to the accumulated stream clock
//     time since the start of the segment - this is directly computable
//     as the sum of the previous and current segment durations (Stop - Start)
//     and the rate applied to each segment
//     The source add this time to the time within each segment to get
//     a total elapsed time
//
// dwSegmentNumber
//     Segment number - starts at 0
//
// Notifies that a segment end has been reached when the
// AM_SEEKING_Segment flags was set for IMediaSeeking::SetPositions
// Passes in an IMediaSeeking interface to allow the next segment
// to be defined by the application

#define EC_SEGMENT_STARTED                  0x1D
//
// ( const REFERENCE_TIME *pStreamTimeAtStartOfSegment, DWORD dwSegmentNumber)
//
// pStreamTimeAtStartOfSegment
//     pointer to the accumulated stream clock
//     time since the start of the segment - this is directly computable
//     as the sum of the previous segment durations (Stop - Start)
//     and the rate applied to each segment
//
// dwSegmentNumber
//     Segment number - starts at 0
//
// Notifies that a new segment has been started.
// This is sent synchronously by any entity that will issue
// EC_END_OF_SEGMENT when a new segment is started
// (See IMediaSeeking::SetPositions - AM_SEEKING_Segment flag)
// It is used to compute how many EC_END_OF_SEGMENT notifications
// to expect at the end of a segment and as a consitency check

#define EC_LENGTH_CHANGED                  0x1E
// (void, void)
// sent to indicate that the length of the "file" has changed

#define EC_DEVICE_LOST                     0x1f
// (IUnknown, 0)
//
// request window notification when the device is available again
// (through WM_DEVICECHANGED messages registered with
// RegisterDeviceNotification; see IAMDeviceRemoval interface)

#define EC_STEP_COMPLETE                      0x24
// (BOOL bCacelled, void)
// Step request complete
// if bCancelled is TRUE the step was cancelled.  This can happen
// if the application issued some control request or because there
// was a mode change etc etc


#define EC_SKIP_FRAMES                      0x25
// ( nFramesToSkip, void ) : internal
// Get the filter graph to seek accuratley.

#define EC_TIMECODE_AVAILABLE                   0x30
// Sent by filter supporting timecode
// Param1 has a pointer to the sending object
// Param2 has the device ID of the sending object

#define EC_EXTDEVICE_MODE_CHANGE                0x31
// Sent by filter supporting IAMExtDevice
// Param1 has the new mode
// Param2 has the device ID of the sending object

#define EC_GRAPH_CHANGED                        0x50
// Sent by filter to notify interesting graph changes

#define EC_CLOCK_UNSET                      0x51
// ( void, void ) : application
// Used to notify the filter graph to unset the current graph clock.
// Has the affect of forcing the filter graph to reestablish the graph clock
// on the next Pause/Run (note that this is only used by ksproxy, when the pin 
// of a clock providing filter is disconnected)


//------------------------------------------
//
// WindowsMedia SDK filter-specific events:
// 
#define EC_WMT_EVENT_BASE                   0x0251
//
#define EC_WMT_INDEX_EVENT                  EC_WMT_EVENT_BASE
// WindowsMedia SDK-originated file indexing status, sent by WMSDK-based filters
//
// lParam1 is one of the enum WMT_STATUS messages listed below, sent by the WindowsMedia SDK 
// lParam2 is specific to the lParam event 
//
//     the following WMT_STATUS messages are sent for this event:
//         WMT_STARTED        - lParam2 is 0
//         WMT_CLOSED         - lParam2 is 0
//         WMT_INDEX_PROGRESS - lParam2 is a DWORD containing the progress percent complete
//
// end WMSDK-originated events
//-----------------------------------------
1	bearsoft	1.1	//------------------------------------------------------------------------------
2			// File: EvCode.h
3			//
4			// Desc: List of standard Quartz event codes and the expected params.
5			//
6			// Copyright (c) 1992 - 2000, Microsoft Corporation. All rights reserved.
7			//------------------------------------------------------------------------------
8
9
10			// Event codes are broken into two groups
11			// -- system event codes
12			// -- extension event codes
13			// All system event codes are below EC_USER
14
15			#define EC_SYSTEMBASE 0x00
16			#define EC_USER 0x8000
17
18			// System-defined event codes
19			// ==========================
20			//
21			// There are three types of system-defined event codes:
22			//
23			// 1. Those which are always passed through to the application
24			// (To be collected by calls to GetEvent or within WaitForCompletion.)
25			// (e.g. EC_ERRORABORT, EC_USERABORT.)
26			//
27			// 2. Those which are pure internal and will never be passed to
28			// the application. (e.g. EC_SHUTDOWN)
29			//
30			// 3. Those which have default handling. Default handing implies that
31			// the event is not passed to the application. However, default
32			// handling may be canceled by calling
33			// IMediaEvent::CancelDefaultHandling. If the default handling is
34			// cancelled in this way, then the message will be delivered to the
35			// application and the application must action it appropriately.
36			// Default handling can be restored by calling RestoreDefaultHandling.
37			//
38			// We will refer to these events as application, internal and defaulted
39			// events respectively.
40			//
41			// System-defined events may have interface pointers, BSTR's, etc passed
42			// as parameters. It is therefore essential that, for any message
43			// retrieved using GetEvent, a matching call to FreeEventParams is made
44			// to ensure that relevant interfaces are released and storage freed.
45			// Failure to call FreeEventParams will result in memory leaks, if not
46			// worse.
47			//
48			// Filters sending these messages to the filter graph should not AddRef()
49			// any interfaces that they may pass as parameters. The filter graph
50			// manager will AddRef them if required. E.g. if the event is to be queued
51			// for the application or queued to a worker thread.
52
53			// Each event listed below is immediately followed by a parameter list
54			// detailing the types of the parameters associated with the message,
55			// and an indication of whether the message is an application, internal
56			// or defaulted message. This is then followed by a short description.
57			// The use of "void" in the parameter list implies that the parameter is not
58			// used. Such parameters should be zero.
59
60			// Other defined EC_ regions:
61			// DVD event codes 0x0100 - 0x0150 (dvdevcod.h)
62			// audio device event codes 0x0200 - 0x0250 (audevcod.h)
63			// WindowsMedia SDK-originated events 0x0251 - 0x0300 (see below)
64
65			#define EC_COMPLETE 0x01
66			// ( HRESULT, void ) : defaulted (special)
67			// Signals the completed playback of a stream within the graph. This message
68			// is sent by renderers when they receive end-of-stream. The default handling
69			// of this message results in a _SINGLE_ EC_COMPLETE being sent to the
70			// application when ALL of the individual renderers have signaled EC_COMPLETE
71			// to the filter graph. If the default handing is canceled, the application
72			// will see all of the individual EC_COMPLETEs.
73
74
75			#define EC_USERABORT 0x02
76			// ( void, void ) : application
77			// In some sense, the user has requested that playback be terminated.
78			// This message is typically sent by renderers that render into a
79			// window if the user closes the window into which it was rendering.
80			// It is up to the application to decide if playback should actually
81			// be stopped.
82
83
84			#define EC_ERRORABORT 0x03
85			// ( HRESULT, void ) : application
86			// Operation aborted because of error
87
88
89			#define EC_TIME 0x04
90			// ( DWORD, DWORD ) : application
91			// The requested reference time occurred. (This event is currently not used).
92			// lParam1 is low dword of ref time, lParam2 is high dword of reftime.
93
94
95			#define EC_REPAINT 0x05
96			// ( IPin * (could be NULL), void ) : defaulted
97			// A repaint is required - lParam1 contains the (IPin *) that needs the data
98			// to be sent again. Default handling is: if the output pin which the IPin is
99			// attached to supports the IMediaEventSink interface then it will be called
100			// with the EC_REPAINT first. If that fails then normal repaint processing is
101			// done by the filter graph.
102
103
104			// Stream error notifications
105			#define EC_STREAM_ERROR_STOPPED 0x06
106			#define EC_STREAM_ERROR_STILLPLAYING 0x07
107			// ( HRESULT, DWORD ) : application
108			// lParam 1 is major code, lParam2 is minor code, either may be zero.
109
110
111			#define EC_ERROR_STILLPLAYING 0x08
112			// ( HRESULT, void ) : application
113			// The filter graph manager may issue Run's to the graph asynchronously.
114			// If such a Run fails, EC_ERROR_STILLPLAYING is issued to notify the
115			// application of the failure. The state of the underlying filters
116			// at such a time will be indeterminate - they will all have been asked
117			// to run, but some are almost certainly not.
118
119
120			#define EC_PALETTE_CHANGED 0x09
121			// ( void, void ) : application
122			// notify application that the video palette has changed
123
124
125			#define EC_VIDEO_SIZE_CHANGED 0x0A
126			// ( DWORD, void ) : application
127			// Sent by video renderers.
128			// Notifies the application that the native video size has changed.
129			// LOWORD of the DWORD is the new width, HIWORD is the new height.
130
131
132			#define EC_QUALITY_CHANGE 0x0B
133			// ( void, void ) : application
134			// Notify application that playback degradation has occurred
135
136
137			#define EC_SHUTTING_DOWN 0x0C
138			// ( void, void ) : internal
139			// This message is sent by the filter graph manager to any plug-in
140			// distributors which support IMediaEventSink to notify them that
141			// the filter graph is starting to shutdown.
142
143
144			#define EC_CLOCK_CHANGED 0x0D
145			// ( void, void ) : application
146			// Notify application that the clock has changed.
147			// (i.e. SetSyncSource has been called on the filter graph and has been
148			// distributed successfully to the filters in the graph.)
149
150
151			#define EC_PAUSED 0x0E
152			// ( HRESULT, void ) : application
153			// Notify application the previous pause request has completed
154
155
156			#define EC_OPENING_FILE 0x10
157			#define EC_BUFFERING_DATA 0x11
158			// ( BOOL, void ) : application
159			// lParam1 == 1 --> starting to open file or buffer data
160			// lParam1 == 0 --> not opening or buffering any more
161			// (This event does not appear to be used by ActiveMovie.)
162
163
164			#define EC_FULLSCREEN_LOST 0x12
165			// ( void, IBaseFilter * ) : application
166			// Sent by full screen renderers when switched away from full screen.
167			// IBaseFilter may be NULL.
168
169
170			#define EC_ACTIVATE 0x13
171			// ( BOOL, IBaseFilter * ) : internal
172			// Sent by video renderers when they lose or gain activation.
173			// lParam1 is set to 1 if gained or 0 if lost
174			// lParam2 is the IBaseFilter* for the filter that is sending the message
175			// Used for sound follows focus and full-screen switching
176
177
178			#define EC_NEED_RESTART 0x14
179			// ( void, void ) : defaulted
180			// Sent by renderers when they regain a resource (e.g. audio renderer).
181			// Causes a restart by Pause/put_Current/Run (if running).
182
183
184			#define EC_WINDOW_DESTROYED 0x15
185			// ( IBaseFilter *, void ) : internal
186			// Sent by video renderers when the window has been destroyed. Handled
187			// by the filter graph / distributor telling the resource manager.
188			// lParam1 is the IBaseFilter* of the filter whose window is being destroyed
189
190
191			#define EC_DISPLAY_CHANGED 0x16
192			// ( IPin *, void ) : internal
193			// Sent by renderers when they detect a display change. the filter graph
194			// will arrange for the graph to be stopped and the pin send in lParam1
195			// to be reconnected. by being reconnected it allows a renderer to reset
196			// and connect with a more appropriate format for the new display mode
197			// lParam1 contains an (IPin *) that should be reconnected by the graph
198
199
200			#define EC_STARVATION 0x17
201			// ( void, void ) : defaulted
202			// Sent by a filter when it detects starvation. Default handling (only when
203			// running) is for the graph to be paused until all filters enter the
204			// paused state and then run. Normally this would be sent by a parser or source
205			// filter when too little data is arriving.
206
207
208			#define EC_OLE_EVENT 0x18
209			// ( BSTR, BSTR ) : application
210			// Sent by a filter to pass a text string to the application.
211			// Conventionally, the first string is a type, and the second a parameter.
212
213
214			#define EC_NOTIFY_WINDOW 0x19
215			// ( HWND, void ) : internal
216			// Pass the window handle around during pin connection.
217
218			#define EC_STREAM_CONTROL_STOPPED 0x1A
219			// ( IPin * pSender, DWORD dwCookie )
220			// Notification that an earlier call to IAMStreamControl::StopAt
221			// has now take effect. Calls to the method can be marked
222			// with a cookie which is passed back in the second parameter,
223			// allowing applications to easily tie together request
224			// and completion notifications.
225			//
226			// NB: IPin will point to the pin that actioned the Stop. This
227			// may not be the pin that the StopAt was sent to.
228
229			#define EC_STREAM_CONTROL_STARTED 0x1B
230			// ( IPin * pSender, DWORD dwCookie )
231			// Notification that an earlier call to IAMStreamControl::StartAt
232			// has now take effect. Calls to the method can be marked
233			// with a cookie which is passed back in the second parameter,
234			// allowing applications to easily tie together request
235			// and completion notifications.
236			//
237			// NB: IPin will point to the pin that actioned the Start. This
238			// may not be the pin that the StartAt was sent to.
239
240			#define EC_END_OF_SEGMENT 0x1C
241			//
242			// ( const REFERENCE_TIME *pStreamTimeAtEndOfSegment, DWORD dwSegmentNumber )
243			//
244			// pStreamTimeAtEndOfSegment
245			// pointer to the accumulated stream clock
246			// time since the start of the segment - this is directly computable
247			// as the sum of the previous and current segment durations (Stop - Start)
248			// and the rate applied to each segment
249			// The source add this time to the time within each segment to get
250			// a total elapsed time
251			//
252			// dwSegmentNumber
253			// Segment number - starts at 0
254			//
255			// Notifies that a segment end has been reached when the
256			// AM_SEEKING_Segment flags was set for IMediaSeeking::SetPositions
257			// Passes in an IMediaSeeking interface to allow the next segment
258			// to be defined by the application
259
260			#define EC_SEGMENT_STARTED 0x1D
261			//
262			// ( const REFERENCE_TIME *pStreamTimeAtStartOfSegment, DWORD dwSegmentNumber)
263			//
264			// pStreamTimeAtStartOfSegment
265			// pointer to the accumulated stream clock
266			// time since the start of the segment - this is directly computable
267			// as the sum of the previous segment durations (Stop - Start)
268			// and the rate applied to each segment
269			//
270			// dwSegmentNumber
271			// Segment number - starts at 0
272			//
273			// Notifies that a new segment has been started.
274			// This is sent synchronously by any entity that will issue
275			// EC_END_OF_SEGMENT when a new segment is started
276			// (See IMediaSeeking::SetPositions - AM_SEEKING_Segment flag)
277			// It is used to compute how many EC_END_OF_SEGMENT notifications
278			// to expect at the end of a segment and as a consitency check
279
280			#define EC_LENGTH_CHANGED 0x1E
281			// (void, void)
282			// sent to indicate that the length of the "file" has changed
283
284			#define EC_DEVICE_LOST 0x1f
285			// (IUnknown, 0)
286			//
287			// request window notification when the device is available again
288			// (through WM_DEVICECHANGED messages registered with
289			// RegisterDeviceNotification; see IAMDeviceRemoval interface)
290
291			#define EC_STEP_COMPLETE 0x24
292			// (BOOL bCacelled, void)
293			// Step request complete
294			// if bCancelled is TRUE the step was cancelled. This can happen
295			// if the application issued some control request or because there
296			// was a mode change etc etc
297
298
299			#define EC_SKIP_FRAMES 0x25
300			// ( nFramesToSkip, void ) : internal
301			// Get the filter graph to seek accuratley.
302
303			#define EC_TIMECODE_AVAILABLE 0x30
304			// Sent by filter supporting timecode
305			// Param1 has a pointer to the sending object
306			// Param2 has the device ID of the sending object
307
308			#define EC_EXTDEVICE_MODE_CHANGE 0x31
309			// Sent by filter supporting IAMExtDevice
310			// Param1 has the new mode
311			// Param2 has the device ID of the sending object
312
313			#define EC_GRAPH_CHANGED 0x50
314			// Sent by filter to notify interesting graph changes
315
316			#define EC_CLOCK_UNSET 0x51
317			// ( void, void ) : application
318			// Used to notify the filter graph to unset the current graph clock.
319			// Has the affect of forcing the filter graph to reestablish the graph clock
320			// on the next Pause/Run (note that this is only used by ksproxy, when the pin
321			// of a clock providing filter is disconnected)
322
323
324			//------------------------------------------
325			//
326			// WindowsMedia SDK filter-specific events:
327			//
328			#define EC_WMT_EVENT_BASE 0x0251
329			//
330			#define EC_WMT_INDEX_EVENT EC_WMT_EVENT_BASE
331			// WindowsMedia SDK-originated file indexing status, sent by WMSDK-based filters
332			//
333			// lParam1 is one of the enum WMT_STATUS messages listed below, sent by the WindowsMedia SDK
334			// lParam2 is specific to the lParam event
335			//
336			// the following WMT_STATUS messages are sent for this event:
337			// WMT_STARTED - lParam2 is 0
338			// WMT_CLOSED - lParam2 is 0
339			// WMT_INDEX_PROGRESS - lParam2 is a DWORD containing the progress percent complete
340			//
341			// end WMSDK-originated events
342			//-----------------------------------------