Doom9's Forum - View Single Post - madVR - high quality video renderer (GPU assisted)

AJ73 · 15th May 2009, 11:30

I invested a lot of time to undderstand pros and contras of all the colorapaces (in the PC area not in the TV area).
I do not understand why YV12 (as a 4:2:0 color subsampling) is better in quality than YUY2 (or UYVY) that has twice as much color information from the original source than YV12 (or NV12).
Is generally more information from the source not better than less?

MPEG-4 and H.264 (not the studio and high quality profiles) use 4:2:0 internally so the information in the source (file, RTP stream) is already lost. But there are also formats like MJPEG that use higher quality color subsampling internally (4:2:2) and some formats also use 4:4:4 color subsampling. My attemt was alwas to avoid any color conversion if possible. That is the reason why YUY2 would have been nice.

You are right that FFDSHOW raw filter can be used for conversion (that is in most cases lossy). But in a multiinstance application the use of an additional filter is bad for the performance.

15th May 2009, 11:30	#1023 \| Link
AJ73 Registered User Join Date: Jun 2008 Posts: 8	I invested a lot of time to undderstand pros and contras of all the colorapaces (in the PC area not in the TV area). I do not understand why YV12 (as a 4:2:0 color subsampling) is better in quality than YUY2 (or UYVY) that has twice as much color information from the original source than YV12 (or NV12). Is generally more information from the source not better than less? MPEG-4 and H.264 (not the studio and high quality profiles) use 4:2:0 internally so the information in the source (file, RTP stream) is already lost. But there are also formats like MJPEG that use higher quality color subsampling internally (4:2:2) and some formats also use 4:4:4 color subsampling. My attemt was alwas to avoid any color conversion if possible. That is the reason why YUY2 would have been nice. You are right that FFDSHOW raw filter can be used for conversion (that is in most cases lossy). But in a multiinstance application the use of an additional filter is bad for the performance.