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

Re: Compressing 2vuy pixels?

At 10:56 AM +1200 3/25/2004, Glenn Anderson wrote:
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.

That is the correct thing to do, but you should only do that if the pixelFormat of the source PixMap is '2vuy'. If the pixelType is not '2vuy', you can't force QuickTime or anything else to give you '2vuy', so you should just ask for 32bit ARGB by setting the wantedPixelSize to 32.

You should also have a cpix resource so any application that can render to '2vuy' knows that your codec can handle it.

Thanks!

Already had the 'cpix', just forgot to mention it.

I suppose all of that makes sense, but it's surprising that the decompress and compress processes aren't symmetric (in that there's at least *some* negotiation over the best pixel format on the decompress side.)

It's still enough support to solve the problem I'm working on, though, since I'll also be controlling the compression sequence and can enforce passing a '2vuy' world when I need to.

--

Dennis

________________________________________________________________________
Dennis J. Wilkinson, II | Any insertions of my foot into my
Principal Software Engineer | mouth are strictly my fault...
Media 100, Inc. |
<mailto:email@hidden> | ...not Media 100's.
_______________________________________________
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.

References: 
 >Compressing 2vuy pixels? (From: "Dennis J. Wilkinson, II" <email@hidden>)
 >Re: Compressing 2vuy pixels? (From: Glenn Anderson <email@hidden>)



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.