Should I Rotate my Movies

[Esquilaxer]

Im using KinomaEX3 for watching long movies. I have the option to rotate my video to landscape. This is cool, since my Zire 72 can only display in portrait mode.

I've heard rumours that rotating movies requires more CPU power, consequently making the movie experience bad.

Since a Zire72 has a 320x320 res. i think it's not nescessary to have landscape, however, i prefer it that way.

If i make my video mode landscape (rotated), will I get a slower performance?

[Tam Hanna]

Well, the pixels will get moved around the screen, possibly leading to severe slowdown as the movement needs to get calculated(at least one MOV between x and y coordinate, but I don't know the XScale assembler language). That is, if the video is rotated on the handheld. If you encode it already rotated, the desktop has to do all the decoding..
I don't really see any advantage in having landscape on a Zire72 though....

[Cyker]

Do the XScale CPUs have any MMX/Altivec-style instructions?

If so, rotation stuff like that will take very little CPU power - MMX instructions eat matrix math for breakfast ;)
Assuming Kinoma uses those codes that is... mmm... I wonder if PalmOS5 even supports such things...!!

[Esquilaxer]

The CPUs for Intel Xscale's line have this "MMX Mobile Edition" sometinhg like that. Well, not so much has been slowed down, but ill stick to landscape, rellay no point