QTW 48 - Transparency Effect with ReelMagic MPEG Card

Technical Q&As


QTW 48 - Transparency Effect with ReelMagic MPEG Card (1-July-95)


Q When using QuickTime for Windows and the Apple Multimedia Kit, we sometimes get a slight see-through effect [[arrowhorizex]] parts of our graphics screens become transparent and we can see the MPEG movie waiting underneath.

Sigma Designs says it is the KEY COLOR, which can be set by an MCI command. Since QuickTime bypasses MCI commands, we cannot set the KEY COLOR, but it must be set somewhere. Is this controlled by QuickTime for Windows itself, by REELMGC.QTW, or somewhere else?

A This could be caused by an MPEG track that is not enabled. If so, you can use SetTrackEnabled to make the MPEG track active. This problem has definitely been identified for the type of MPEG files that can be imported on the Mac and then exported as movie files with MPEG tracks.

If you have QuickTime for Windows 2.0.2, you can issue a SET KEY COLOR MCI command. This does not cause problems with 2.0.2, because we now allow both MCI and the QuickTime for Windows C APIs to co-exist.

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