Hi,
Sorry for the repeat post. All other similar topic gives me headache!
IMO, there is INPUT level (DVD, software MPEG2 decoders) and OUTPUT level (Overlay. VMR, display card output).
For normal PC operation (Word, PhotoShop, Web) I guess both INPUT and OUPUT are at 0-255 level.
DVD is suppose encoded in video level which is in the range of 16-235. PC desktop has all the value in 0-255.
First question, how's software MPEG2 decoders (WinDVD, PowerDVD, Cine, NVDVD) treats DVD content? As 16-235 or 0-255 level?
If the MPEG2 decoder process DVD as 16-235, then where is 235 data? Throw away?
Does video renderer (Overlay, VMR) remap/expand 16-235 to 0-255? I guess not because not all video content are DVD MPEG2. If video renderer does level conversion then other non DVD content will have problem.
Then how's the 16-235 fit to the display card OUTPUT level? All PC display card output in 0-255 level, right? I don't see there is a option for 16-235 level output in display property. And if so then normal desktop will be affected.
So how all these add up? Personal I think in HTPC world everything is treated as 0-255. I have no problem with these as we get everything from DVD.
I always get the 2 moving black bars and 2 moving white bars in AVIA.
In the 2 moving black bars pattern, I guess the brighter (right) bars is at 7.5 IRE (higher than 16), the darker (left) bar is at between 0-16 and the background is at IRE 0 (for 16-235 player, it means 16, for 0-255 player, it means 0, I guess). If the player (software MPEG2 decoder) works in 16-235, then the darker bar will be invisible.
All in all, it's not a issue for me. And I don't want to think it anymore as it still cause me headache!
regards,
Li On
Sorry for the repeat post. All other similar topic gives me headache!
IMO, there is INPUT level (DVD, software MPEG2 decoders) and OUTPUT level (Overlay. VMR, display card output).
For normal PC operation (Word, PhotoShop, Web) I guess both INPUT and OUPUT are at 0-255 level.
DVD is suppose encoded in video level which is in the range of 16-235. PC desktop has all the value in 0-255.
First question, how's software MPEG2 decoders (WinDVD, PowerDVD, Cine, NVDVD) treats DVD content? As 16-235 or 0-255 level?
If the MPEG2 decoder process DVD as 16-235, then where is 235 data? Throw away?
Does video renderer (Overlay, VMR) remap/expand 16-235 to 0-255? I guess not because not all video content are DVD MPEG2. If video renderer does level conversion then other non DVD content will have problem.
Then how's the 16-235 fit to the display card OUTPUT level? All PC display card output in 0-255 level, right? I don't see there is a option for 16-235 level output in display property. And if so then normal desktop will be affected.
So how all these add up? Personal I think in HTPC world everything is treated as 0-255. I have no problem with these as we get everything from DVD.
I always get the 2 moving black bars and 2 moving white bars in AVIA.
In the 2 moving black bars pattern, I guess the brighter (right) bars is at 7.5 IRE (higher than 16), the darker (left) bar is at between 0-16 and the background is at IRE 0 (for 16-235 player, it means 16, for 0-255 player, it means 0, I guess). If the player (software MPEG2 decoder) works in 16-235, then the darker bar will be invisible.
All in all, it's not a issue for me. And I don't want to think it anymore as it still cause me headache!
regards,
Li On