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Multiple Graphs in DirectShow

Applications sometimes need to start and stop some filters independently of others, and to switch connections dynamically. In this article, Geraint Davies shows how to solve these problems using multiple, related graphs of filters. The accompanying source code includes GMFBridge, a complete multiple-graph toolkit, and two example applications. GMFPlay shows how to view multiple clips as a single movie, and GMFPreview demonstrates how to keep showing the preview stream from a video capture device while starting and stopping capture into different files.

For more details on GMFBridge, see the GMFBridge page.

Published: November 2004. Latest update March 2007

Download here:

• Multiple Graphs in DirectShow article (requires Acrobat Reader 5.0 or greater)
• Source code to GMFBridge tool and example applications

DirectShow Parsers

First in the series: an introduction to DirectShow parser filters, together with a fully-working, seekable, MPEG-1 parser sample.

If there is a playback engine at the heart of DirectShow, it is the parser filter. The requirements and behaviour of the parser are not widely understood, although there are a number of cases where developers may need to create their own. This article, and the accompanying sample parser, sets out to show the how and why of DirectShow parser development.

Published: March 2004.

Download here:

• Introduction to Parsers Article (requires Acrobat Reader 5.0 or greater)
• Sample MPEG-1 parser code