CBaseVideoRenderer Class

Microsoft DirectShow 9.0

CBaseVideoRenderer Class

The CBaseVideoRenderer base class is used for building video renderer filters.

Protected Data Members

m_bDrawLateFrames	Flag to signal that no frames are to be dropped. Debug only. This destroys synchronization.
m_bSupplierHandlingQuality	TRUE indicates quality control messages are being handled. This lets the renderer know to wait until as late as possible to drop frames itself, and to display the next frame very early after the supplier has dropped a frame.
m_cFramesDrawn	Total number of frames that have been drawn since streaming started.
m_cFramesDropped	Cumulative frames that have been dropped in the renderer since streaming started. Frames can also be dropped upstream without the renderer recognizing them.
m_idDecision	MSR_id for the decision code of ShouldDrawSampleNow.
m_idDuration	MSR_id for the duration of a frame.
m_idFrameAccuracy	Performance log identifier for the time in milliseconds that the frame was late.
m_idFrameAvg	Performance log identifier for the average frame time that is used for synchronization and quality control.
m_idQualityRate	MSR_id for the quality rate requested.
m_idQualityTime	MSR_id for the quality time requested.
m_idRenderAvg	Performance log identifier for the average renderer time recorded.
m_idSchLateTime	MSR_id for how late the frame was when scheduled.
m_idSendQuality	MSR_id for timing the notifications (unused).
m_idTimeStamp	MSR_id for a frame time stamp .
m_idWait	Performance log identifier for the recorded wait time (unused).
m_idWaitReal	Performance log identifier for the true wait time.
m_iSumFrameTime	Sum of the interframe times; needed for the property page.
m_iSumSqAcc	Sum of the squares of the accuracies (in milliseconds) needed for the property page.
m_iSumSqFrameTime	Sum of the squares of interframe times; needed for the property page.
m_iTotAcc	Sum of the accuracies (in milliseconds) needed for the property page.
m_nNormal	Number of consecutive frames drawn at their scheduled time. A negative number indicates that a frame has just been dropped by the renderer.
m_trDuration	Duration of the last frame (difference between the start and end times).
m_trEarliness	How early a frame is allowed to be played when a frame has just been dropped.
m_trFrame	Most recently recorded time between frames. Used in statistical measurements.
m_trFrameAvg	Average interframe time in reference time units.
m_trLastDraw	Time of previous frame. Used for interframe time references.
m_trLate	Amount of time that the current frame was late. Used in statistical measurements.
m_trRenderAvg	Time that frames are taking to perform the bit-block transfer.
m_trRenderLast	Time for the last frame bit-block transfer.
m_trRenderStart	Time the bit-block transfer started. Used to get m_trRenderLast.
m_trThrottle	Period to insert after rendering each frame, typically used when audio quality has been increased and video performance must be decreased to allow this.
m_trWaitAvg	Average wait time in reference time units.
m_tStreamingStart	Used for property page statistics. Represents the start time of the current streaming process or the previous streaming process if not currently streaming.

Member Functions

CBaseVideoRenderer	Constructs a CBaseVideoRenderer object.
GetStdDev	Estimates the standard deviation in milliseconds between when each frame is due and when it is actually rendered, for per-frame statistics.
PreparePerformanceData	Sets the m_trLate and m_trFrame values of the current frame.
ThrottleWait	Inserts a wait period after each frame.

Overridable Member Functions

JoinFilterGraph	Sends an EC_WINDOW_DESTROYED event when filter is removed from the filter graph.
OnDirectRender	Collects timing information that controls synchronization and quality control.
OnRenderEnd	Records information for quality control and synchronization.
OnRenderStart	Records information for quality control and synchronization.
OnStartStreaming	Resets all times that control streaming.
OnStopStreaming	Called at the end of streaming to fix times for the property page report.
OnWaitEnd	Called when a wait time ends. Performance logging only.
OnWaitStart	Updates times spent waiting and not waiting. Performance logging only.
RecordFrameLateness	Records how timely the rendering occurred and gathers statistics for the property page.
ResetStreamingTimes	Resets all times that control the streaming.
ScheduleSample	Sets up an advise link with the clock.
SendQuality	Sends a quality message to indicate what the supplier should do about quality.
ShouldDrawSampleNow	Determines if the video should be drawn when it is due, without setting a timer advise link with the clock.

Implemented IQualProp Methods

get_AvgFrameRate	Retrieves the average frame rate since streaming started in frames per 100 seconds.
get_AvgSyncOffset	Retrieves the average of the time in milliseconds between when each frame was due and when it was actually rendered. This applies to all frames since streaming started.
get_DevSyncOffset	Retrieves the standard deviation of the time in milliseconds between when each frame was due and when it was actually rendered for all frames since streaming started.
get_FramesDrawn	Retrieves the number of frames drawn since streaming started.
get_FramesDroppedInRenderer	Retrieves the number of frames dropped by the renderer. Frames can also be dropped upstream.
get_Jitter	Retrieves the standard deviation of the time in milliseconds between each frame and the next. This applies to all frames since streaming started.

Implemented IQualityControl Methods

Notify	Notifies the recipient that a quality change is requested.
SetSink	Sets the IQualityControl object that will receive quality messages.