[DBMandrake]

• NC3: Only need a confirmation dialogue when resolution has actually changed

Fantastic. This "feature" of Gotham was driving me crazy, when I swap between different monitors/screens of different resolutions...

• Fix for video stutter after seek on streams without b frames

As I reported this problem I can confirm that the new firmware fixes the issue.

Some words from popcornmix:

The Pi has some quite advanced scaling hardware which is able to do higher quality scaling than other ARM (and probably most PC) boxes.

I've added an API to the firmware where the scaling kernel (a 32 tap filter) can be controlled.
I've hooked that into the sharpness control on the video OSD.
I've used the sharpness control for now as that gives an unobtrusive slider at the top of screen, rather than the scaling method drop down which obscures most of the screen.

Basically sharpness=0 uses the default scaling kernel (Sinc over the range +-3*PI with Hamming window applied).
Each click to the right of that uses a different kernel. I've implemented 9 kernels. Try them and report what you prefer.

Some suggestions:
It's probably best to pause the video when there is some detail visible (like text) to see the effect.
Don't try it when video is 1080p and display is 1080p or you won't see anything. It's more interesting when playing SD content on a HD display
It's not magic. The kernels are a compromise between sharpening (producing more detail, but increasing noise) and blurring (hides the noise and the detail).
The best option for SD video may be different to the best option for 720p.

Can I confirm that these options are also intended for downscaling as well as upscaling ? For example if I play back 1080p content on a 1680x1050 screen.

I can definitely see a difference between them in that situation although I'm not sure which one I prefer yet...

BTW, only 7 of the 9 "kernels" seems to be working, if I adjust sharpness 8 clicks to the right from zero (or any number greater than 8) it seems to switch to scaling with no anti-aliasing. (All options from 8 onwards look the same and very pixellated)