I'm also seeing this problem on my Mac Mini. First my hardware and OS specs:
Model Name: Mac mini
Model Identifier: Macmini2,1
Processor Name: Intel Core 2 Duo
Processor Speed: 1.83 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 2 MB
Memory: 1 GB
Bus Speed: 667 MHz
Boot ROM Version: MM21.009A.B00
SMC Version (system): 1.19f2
Intel GMA 950:
Chipset Model: GMA 950
VRAM (Total): 64 MB of Shared System Memory
Vendor: Intel (0x8086)
Device ID: 0x27a2
Revision ID: 0x0003
Resolution: 1680 x 1050 @ 60 Hz
Pixel Depth: 32-Bit Color (ARGB8888)
Display Serial Number: WM49774L03CL
Main Display: Yes
OS is Snow Leopard 10.6.8, the screen is connected by VGA and as above is in 1680x1050. Audio out is analog.
The symptoms are every video I play gives the error "Video rendering failed to init video filters/scalers falling back to bilinear scaling", but then proceeds to play. I was seeing this on Memphiz's airplay test build 10 and now on official Beta 2. I'm also seeing a couple of additional possibly related problems though.
On Memphiz's airplay build if I set rendering to software only attempting to play video would always result in a crash back to the OS X desktop and a crash reporter message, on Beta 2 it seems to play without the renderer error message appearing.
I am seeing an additional problem on Beta 2 which I was not seeing on Memphiz's airplay test build - sometimes when first launching XBMC the graphics start glitching in a crazy way. Impossible to describe so I recorded some video and uploaded to youtube:
If I command tab to the finder with the XBMC window still animating in the background (in default full screen mode, so it appears to be wall paper) then the glitching stops, when I command tab to bring XBMC back to the foreground I have a 50/50 chance of the glitching returning or not returning.
Edit: here is a second video showing command tabbing and how sometimes when XBMC returns to the foreground the glitching stops but usually it does not:
To test Beta 2 I moved my (userdata containing) XBMC folder out of the way so this is a completely fresh install of Beta 2 to which I have only added a video source. Here is the debug log taken when launching a video which brings up the video rendering error message:
Here is a debug log of Frodo 12.2 playing the same video without any rendering error message: (also no graphical glitches)
Manually setting shaders to ARB as suggested above doesn't help for me - I still get the same error.
Any other information needed or testing needed please let me know, as although the rendering error is only annoying the video glitching is a bit of a show stopper for me.