Quote:
Originally Posted by
Smackrabbit 
Quick Sony BDP-S590 Notes:
- Perfect at 4:2:2 and 4:4:4
- RGB is broken. Green hits 254 at 218, not 254, or 86%.
So, if you are seeing 90% but not 92% in RGB, something else in that testing method is broken, as from 86% on up they would be identical in RGB mode.
Thank you for posting this S590 info, Chris.
Quote:
- Perfect at 4:2:2 and 4:4:4
By "perfect", I take it you mean that there's no clipping apparent in the S590's HDMI YCbCr color modes, in the standard video color range, which is exactly what my tests show above for the S185, S380 and S390.
In spite of our different approaches, so far your HD video test results on the S590 are looking pretty much identical to my PNG and DVD test results on the S185, S380, and S390.
We both agree that there's no visible clipping of green (or other colors) near white in the normal video color range in the YCbrCr HDMI color modes on these players. And we also agree that there
is some
visible clipping of the green values
within the standard 16-235 video color range in the RGB HDMI color mode. All we appear to disagree on at the moment is exactly where the clipping in the RGB mode begins. But I think I can explain that as well, if you'll bear with me...
To calculate % stimulus for something like a PNG file in 24-bit (8-bit per color component) 0-255 RGB format, all you need to do is divide the RGB clip value by 255.
Calculating % stimulus for something like a DVD or BD video file in 16-235 YCbCr video format is a bit more involved though, because the head and foot room (and video black step) need to be factored in. Here are two simple equations which can be used for that:
(RGB clip value - 16) / (235 - 16) = stimulus
or simply...
(RGB clip value - 16) / 219 = stimulus
If you're using Rec. 709 compliant high-definition YCbCr Blu-ray video files for the S590 tests, then you need to use an equation like this, rather than simply dividing by 255, or 254 as you've done above. (I figured you were already aware of this btw, or I probably would have mentioned it earlier.)
If your RGB "clip value" of ~218 is plugged into either of these video equations, the answer that comes out is
92.24% stimulus.
(218 - 16) / 219 = .9224
Since you can't measure above 254 on your equipment though, I'm guessin that the
actual clip point for green on the player is probably a step higher, which would be 219, or about
92.69% stimulus.
(219 - 16) / 219 = .9269
Either way, the result is consistent with my PNG and DVD-Video tests in the RGB HDMI color modes on the Sony S185, S380 and S390 BD players (
92-93% stimulus as shown on the
table above). So it appears my methods are workin pretty well despite our different approaches. I would not describe the YCbCr HDMI color modes on these players as "perfect" though, because my PNG and DVD tests also suggest they're pushing green in
both the RGB and YCbCr HDMI color modes. Perhaps you'll find something similar on the S590 as well, as you get a bit deeper into your color tests on that unit.
I also played around a bit with the different Picture Quality Modes in the Video Settings on the S390. And I can confirm that there are differences in the clipping of video content when switching between those settings in the HDMI RGB color mode. Here's the way my DVD-Video tests break-down...
| Video Settings / Picture Quality Mode: |
Green Clip Point in RGB HDMI Color Mode: |
| Standard |
92-93% Stimulus |
| Bright Room |
91-92% Stimulus |
| Theater Room |
100% Stimulus
(no clipping in standard color range) |
This feature seems quite buggy on the S390 btw. I had to cycle the power off and on to get each setting to "stick". My general recommendation would be to leave it set at "Standard".
Although there was no clipping apparent in the "Theater Room" mode (in the standard 16-235 video color range), the gamma on that setting also looked a bit funky to me. So I don't recommend using it. All three modes appear to push green as well. As far as I can tell, there is no way to eliminate the green push on the S185, S380 and S390 with just the players' settings alone, unless Sony can do fix for the issue. Some users
might be able to compensate for this issue on their HDTV's though, especially if they have advanced decoder controls like in the service mode of my Sony CRT.
However, the green
clipping can be avoided on these players by simply using the YCbCr HDMI color modes rather than the RGB mode. This is borne out by both Chris's and my tests. Unfortunately, using the YCbCr color modes is not an option for me, because the DVI input on my older Sony CRT only works with the RGB HDMI color mode.
Also, in case it's still unclear which tests I performed on which displays, here's a quick synopsis...
| HDMI Color Mode: |
Display(s) Used for Tests: |
| RGB |
Gateway FHD2400 LCD (HDMI) & Sony 34XBR800 CRT (DVI) |
| YCbCr 4:2:2 |
Gateway FHD2400 LCD (HDMI) |
| YCbCr 4:4:4 |
Gateway FHD2400 LCD (HDMI) |
I made a few tweaks to the graph and other posts above to hopefully make this somewhat clearer there as well.
One other thing I'll add is that the Picture Quality Modes in the Sony players' Video Settings appear to have no effect on PNG, JPEG or other still images. Those modes only seem to apply to video content (i.e. DVDs, BDs, and other video files).