3D TV has "Cross Chatter" in Left and right eye using Anaglyph-to-sbs Shader.

[SixSpeedDeath]

The brief: I'm trying to modify an anaglyph-to-sbs shader to work on a 1080 TV for lr-beetle-vb, and the 2 images are ghosting over one another, I THINK it may have something to due with the HDMI output from the Pi.

Detailed version:
I'm using the base shader found at https://github.com/mrgriscom/emu/blob/master/configs/retroarch/shaders/shaders_glsl/anaglyph-to-sbs.glsl

I found a way to get the shader to work with my 3D TV and after some tweaking, it works!

However, the 2 images (which are white and blue until I figure out how to make them both red) can be seen in both eyes of my active 3D Glasses. Dimmer in the unintended eye.

I was sure that my old PS3 3D glasses were to blame, so I threw on Mad Max in 3D, forgot what I was doing for an hour, and verified that the 3d effect works.

Tried Crysis on 360 in side by side 3D mode, again, it works SUPER well.

The only question I can think to ask here is if HDMI output is different from the Pi (which is largely set up for the UK) and the US? if there is a 60hz/50hz setting, maybe the timing for the side by side is off, so my TV can't perfectly separate the 2 images from the Pi without a little overlap?

Any ideas on this?

[mediamogul]

@sixspeeddeath

This might be related to a similar issue that prevents me from watching 3D movies through Kodi on RetroPie. Do you happen to have any overscan settings configured? If so, it would prevent the two side-by-side images from folding over each other in the way they need to.

[SixSpeedDeath]

I can never remember which way overscan goes (it's binary, so I swap it on/off based on if it works the way I want to) But I have my TV set to "Just scan", and the image fills the screen. I think that means overscan is off?

[SixSpeedDeath]

@mediamogul

[SixSpeedDeath]

So, I forced 1080p 60Hz in the Config.txt, (hdmi_mode=16) , and the ghosting is still present.

Unless anyone has information on how Side-by-side 3d works, it looks like I'll have to understand the process better to get any further on this particular issue.

[mediamogul]

@sixspeeddeath said in HDMI output and region settings question.:

Unless anyone has information on how Side-by-side 3d works

If you've ever seen SBS video outside of a 3D TV, it's really just two horizontally squashed 720p images side-by-side (SBS) from each other. Both images need to be perfectly folded on top of each other and then expanded to 1080p for the effect to work. Anything that prevents that process is likely to be the problem. As I mentioned earlier, for me it was an overscan border that prevented the two images from properly overlaying, so you might look for similar possibilities.

[SixSpeedDeath]

@mediamogul both images fold over one another properly, but when I close my left eye, there is a light grey image from the right image, and vice versa. (I tried uploading an image from dropbox, but apparently I'm as much a novice in forums as I am with the Pi)

The active 3D shutters are supposed to time the opening and closing to keep left and right separated, and sjnce both images are side by side, teeeeechnically, the TV is supposed to cut the image in half, stretch it and time the shutters on the glasses to sync the refresh of TV and glasses.

I can only think it was a TV thing, or the difference between native 3D signals from my Xbox One X. And the side by side 3D effect, but the 360 with Crysis plays side by side 3d perfectly, leading me to believe it's pi side.

It looked so simple in concept, LOL.

[mediamogul]

@sixspeeddeath said in HDMI output and region settings question.:

I can only think it was a TV thing

It might just be an issue with the shader reacting with certain games. I've experimented with VirtualBoy 3D effects on a couple of different hardware/software 3D processes in the past and cross-chatter (image ghosting) was consistently a problem. 'Virtual Boy Wario Land' was always my test game, as it had some of the least amount of cross-chatter. How does it look on your setup?

[mediamogul]

I would recommend changing the thread title here to something more befitting a 3DTV question. You'll have a better chance of catching someone's eye who deals with this type of thing more frequently.

[SixSpeedDeath]

I'll give it a look when I get home. I was testing with Jack Bros.

"Cross Chatter" i think is a more adequate description than ghosting, now that i've googled ghosting more.

The only other thing I can think of is that on 3D Blu-Rays, the worst ghosting is always around White on black, which is presently what the Shader displays.

I Will Check with Wario, and I'll see if I can figure out how to change the sbs shader to keep the red hue, in case the contrast is what's causing the problem.

[cdelaorden]

Hi @sixspeeddeath

Im trying the same thing on my tv. The crosstalk you are talking about is caused by the distance between eyes, you need to move the warning message so if you see it without 3d lenses it overlaps with each other.

I edited the first lines of the glsl to this

#define eye_sep 0.605
#define y_loc 0.32
#define ana_zoom 1.3
#define WIDTH 2.4
#define BOTH 0.52
#define HEIGHT 2.4
#define palette 1.0
#define warpX 0.00
#define warpY 0.00

and now its almost perfect on my tv anyway (and LG 3d with passive lenses).
The only problem I have now its that the result image only uses 50% of the tv realstate