Mailing Lists: Apple Mailing Lists
Image of Mac OS face in stamp
 
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Compressing 2vuy pixels?

I'm attempting to modify a codec to support compressing '2vuy' pixmaps directly (in the interest of avoiding unnecessary trips to RGB in a few cases.)

I've coded decompressors that can render *into* '2vuy' space, and had expected that the code would be symmetric for compressors (i.e. have a 'cpix' resource indicating that '2vuy' is a supported format, and in my ImageCodecPreCompress implementation, adjust the CodecCapabilities struct and the wantedSourcePixelType fields appropriately.)

I immediately notice 2 things:

- the wantedSourcePixelType field is not a Handle as the wantedDestinationPixelTypes field is in the corresponding decompressor struct

- it is listed as "undocumented" in the online docs

Since I only have the one Y'CbCr space to support, I tried the obvious: setting the capabilties struct's wantedPixelSize to 0 and the wantedSourcePixelType field to '2vuy', but that causes exports from QuickTime Player (even exports from movies that I know to be able to render into '2vuy') to fail immediately after calling my codec's ImageCodecPreCompress function.

I can't seem to find any information about how to do this online or in the list archives, but have noted that some Apple codecs seem to support this -- I can create a compression sequence whose source pixmap is 2vuy for several codec types, and they do seem to compress properly.

Some up-to-date codec sample code in that spiffy new library wouldn't be a bad start, but lacking that, has anyone done this successfully, and if so, what am I missing?

--

Dennis

I am responsible only for the spaces in the above message. All
other characters are arranged randomly.
_______________________________________________
quicktime-api mailing list | email@hidden
Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/quicktime-api
Do not post admin requests to the list. They will be ignored.



Visit the Apple Store online or at retail locations.
1-800-MY-APPLE

Contact Apple | Terms of Use | Privacy Policy

Copyright © 2007 Apple Inc. All rights reserved.