cbaserenderer-onrenderstart.md

description	ms.assetid	title	ms.topic	ms.date	topic_type	api_name	api_type	api_location	ms.custom
The OnRenderStart method is called when rendering is about to start.	46af24cf-9075-4ebc-a49b-85f8f0c3da6f	CBaseRenderer.OnRenderStart method (Renbase.h)	reference	4/26/2023	APIRef kbSyntax	CBaseRenderer.OnRenderStart	COM	Strmbase.lib Strmbase.dll Strmbasd.lib Strmbasd.dll	UpdateFrequency5

CBaseRenderer.OnRenderStart method

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The OnRenderStart method is called when rendering is about to start.

Syntax

virtual void OnRenderStart(
   IMediaSample *pMediaSample
);

Parameters

pMediaSample

Pointer to the sample's IMediaSample interface.

Return value

This method does not return a value.

Remarks

The CBaseRenderer::Render method calls this method. It does nothing in the base class, but the derived class can override it; for example, to collect quality-control data.

Requirements

Requirement	Value
Header	Renbase.h (include Streams.h)
Library	Strmbase.lib (retail builds); Strmbasd.lib (debug builds)

See also

CBaseRenderer Class