I've never heard of a top-quality linux video renderer
Understanding the entire playback chain of video will take a lot of time to fully understand. It then takes even more time to understand how it applies directly to your specific display, and what practical differences you'll see by toggling certain settings.
Example, one of the differences always discussed in blu ray playback on an HD display (FHD source on FHD display) is chroma upscaling. Yet long into a discussion thread of some not seeing any difference and those noticing a difference, it was revealed that most plasma sets and displays that process chroma 4:2:0 wouldn't notice the benefit from chroma upscaling.
From the theoretical point of view madvr is a superior video renderer
- high quality chroma upsampling
- high quality scaling (bicubic, mitchell, lanczos, spline etc)
- high quality YCbCr -> RGB conversion
- gamut & gamma correction for display calibration
- full 16bit processing queue
- final 16bit processing result is dithered down to RGB output bitdepth
- bypasses graphics card's video (damage) algorithms
Also a good quote from the developer, madshi, regarding his intent with madvr
madVR performs slower because it does things differently. EVR (and probably XBMC, but I don't know that for sure) are making use of GPU hardware circuits where they can, e.g. color conversion etc. And they often default to low bitdepth buffers. On the other hand, madVR does everything itself, in high bitdepth, with dithering as the last step, in order to be able to guarantee that quality is impeccable. GPU circuits might also be able to produce good quality, but that depends on the GPU manufacturer, model, OS, driver version, driver settings and the constellation of the planets. Try switching MPC-HC's EVR renderer to "Full floating point processing" and you'll see that EVR suddenly isn't so fast, anymore. By default many EVR implementations work in 8bit, dropping BTB/WTW, introducing banding etc etc. But it's fast that way, of course. I could program madVR that way, too. But we don't need another low quality renderer alternative. I've always said that madVR's primary focus is quality and that I'm not taking shortcuts on the way. But that doesn't mean that madVR would be "terribly unoptimized". It isn't. Just my priority is different. Quality over speed. Still at the same time my algorithms are reasonably well optimized. For example, I've even written separate shader routines for upscaling with an exact scaling factor of 2x or 3x to improve performance on slower GPUs. I don't think any other renderer has invested that much optimization work.
A newer feature of madvr is FRC, which is kind of similar to SVP (smooth motion video project). SVP set out to perform frame interpolation via CPU and output 60fps to a 60Hz display.
A lot of 60Hz displays (and most 120Hz displays which are really 60Hz sets with inverted frames injected between source frames - marketing schpeel) will not directly handle blu ray source 1080p/23.976. Instead they take use a frame duplication algorithm (3:2 pull down) to output 60Hz. In fast action scenes and panning scenes these can appear to contain judder. If you are watching a blu ray from source then you should be pretty convinced that this is a result of your display algorithm as opposed to some video file conversion quality loss (which you may see if watching downloaded or handbraked videos). SVP creates frames for 60fps output, but AFAIK madvr makes use of existing frames. Madvr's target was frame-blending rather than frame interpolation. Some people truly prefer frame interpolation (like you'll find on new flat panel displays with terms like motionflow, etc). SVP gives you a way to apply your own frame interpolation and keep your old 60Hz display. I don't think it's really been compared to applying OEM frame interpolation to blu ray source (we were just talking about this in the above forum). MadVRs FRC is aimed at eliminating the judder you'd see rather than providing a frame interpolation effect. Shouldn't notice it much if your display already outputs 24p without the 3:2 duplication algorithm (might not even notice it then)Here is a good link
to hardware requirements for various madvr levels
Also, here are some screenshots showing madvr's superior chroma upscaling First Second
If you look at those two and can't really see much difference you aren't alone, but here is a more concrete example (to me) of the practical image superiority when viewing gradation. without madvr with madvr
The gradation looks pretty obvious to me for a static image. If I load both those images as fullscreen windows and rapidly switch between them then I lose site of which is which.
Finally, what most seem to say is the largest benefit of madvrs quality-focused processing can be seen in upscaling