Retired Document
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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.
References:
Sequence Grabber Source, Video and Channel Bounds - Technical Q&A 1250
Video Capture with multiple IIDC cameras - Technical Q&A 1365
Document Revision History
Date | Notes |
---|---|
2005-01-06 | New document that discusses how to determine the resolution of a captured image from an IIDC device |
Copyright © 2005 Apple Computer, Inc. All Rights Reserved. Terms of Use | Privacy Policy | Updated: 2005-01-06