Does the Sequence Grabber add clean aperture and aspect ratio information on behalf of a Video Digitizer?
The Sequence Grabber will always automatically generate Clean, Production and Encoded dimensions for a captured video track based on the Clean Aperture (kICMImageDescriptionPropertyID_CleanAperture, ‘clap’) and Pixel Aspect Ratio (kICMImageDescriptionPropertyID_PixelAspectRatio, ‘pasp’) Image Description extensions returned by the Video Digitizer selector GetImageDescription. In some versions of QuickTime since 7.1, when a Video Digitizer does not return Clean Aperture and Pixel Aspect Ratio information the Sequence Grabber will automatically generated Clean, Production and Encoded dimensions based on the codec type (this is fine when compressing to DV or DVCPRO50 for example). However, specifically in the case of uncompressed video (where this information cannot be determined based only on codec type) the generated Clean, Production and Encoded dimensions assume the Pixel Aspect Ratio is 1:1. This assumption may not be correct and can lead to unexpected capture results. In future vers
