My video review

[fanoush]

Yes, I know which framebuffer you mean. Just forgot what we are trying to solve here It is the rotation that is the problem here, not double buffering. Double buffering would solve only vertical tearing here, not diagonal one caused by updating display framebuffer in different direction. Not sure about clever DMA doing rotation on the fly but the chipset has some IPU unit which could at least scale (?) and do YUV<->RGB conversion, I wonder if it could rotate too? And if not maybe some optimized assembly code wouldn't hurt performance so much. There are even some SIMD instructions but maybe it could not help much here since it is just byte shuffling in memory.

 

[Exophase]

Yes, I know which framebuffer you mean. Just forgot what we are trying to solve here It is the rotation that is the problem here, not double buffering. Double buffering would solve only vertical tearing here, not diagonal one caused by updating display framebuffer in different direction. Not sure about clever DMA doing rotation on the fly but the chipset has some IPU unit which could at least scale (?) and do YUV<->RGB conversion, I wonder if it could rotate too? And if not maybe some optimized assembly code wouldn't hurt performance so much. There are even some SIMD instructions but maybe it could not help much here since it is just byte shuffling in memory.

I think anything you do will be dominated by memory bandwidth, unless you somehow do it totally wrong like GPH must have for their SDL fix. It's going to take a chunk, probably not a completely negligible one with the memory speed of the part. It wouldn't completely kill performance but it would at least be noticeable if something was on the edge.

It'd perform better with software that wrote out to that mode naturally. But before any of these things can be done the LCD controller has to be reconfigured to stop rotating the input. Hopefully the SPI interface on the SoC is well known and all that.

 

[sold]

Dammit, I didn't notice much screen tearing in the games I tried out, mainly nes games, but I tried guardian heroes and it was real bad. On the snes emulator, Front Mission Gun Hazard plays really well with no screen tearing. I have a black Dingoo. At least it seems to overclock ok.

What causes screen tearing? Is it something to do with the refresh rate of the screen? Or is it a software issue? And why is it only visible in some games and not others?

 

[WarmFluffyUK]

umm I think you forgot to mention the touchscreen on the wiz.

Yeah, funny that innit, considering it's one of it's major features

 

[Exophase]

umm I think you forgot to mention the touchscreen on the wiz.

Yeah, funny that innit, considering it's one of it's major features

Guess it's easy to forget about it when almost nothing uses it right now.

 

[rx_shorty]

Guess it's easy to forget about it when almost nothing uses it right now.

Heh true but it allows me to play my favo game at the moment: Animatch made by Ruckage