Sequence Grabber - Determining the capture resolution of an IIDC device

Q: I'm trying to find a way to determine the capture resolution of an IIDC device. I'm currently using two functions; SGGetSrcVideoBounds and VDGetDigitizerRect. Both however return a size of 1600x1200 instead of 640x480 when using the Apple iSight camera. What's the best way to do this?

A: While the relationship between the Source, Video and Channel bounds is described in Technical Q&A 1250, these bounds do not necessarily reflect what a particular device will generate.

In the case of the QuickTime IIDC Video Digitizer (used by the Apple iSight ), the actual image size isn't determined until the Sequence Grabber Video Channel is fully configured. Once this is done you can call SGGetChannelSampleDescription or the lower level VDGetImageDescription to determine the captured image size.

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Document Revision History

DateNotes
2005-01-06Discusses how to determine the resolution of a captured image from an IIDC device

Posted: 2005-01-06

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