Introducing DSWebcamCap

Introducing DSWebcamCap

The DirectShow application DSWebcamCap captures separate video and audio inputs from a Logitech webcam to a file. Although a specific brand of webcam is explicitly specified in the code of DSWebcamCap, it is very easy to modify a few string constants and have the program work with any version of webcam. The application takes the combined streams and puts them into a filter known as the WM ASF Writer. This filter compresses audio and video streams using the powerful Windows Media Video codecs. The encoded content is put into an ASF file, which, according to the Microsoft guidelines, should have either a .WMA or .WMV file extension. (In this case, we re creating a file with the .ASF extension, which stands for Advanced Systems Format. This file will be functionally identical to a file with a .WMV extension. ASF is a container format, a file type that can contain any of a number of stream formats, including both WMV and WMA, so it s well suited to this task.) The WM ASF Writer allows you to select a variety of compression levels for the output file, so you can create very small files from a rich video source.