getting Jailbars on stream

[Jackafur]

Hi ive been lurking around here recently. I got a PVM 20L5 recently and just started capturing and streaming RGB via twitch.tv. Sorry if this isnt the best place for this but you guys seem to be pretty knowledgeable in this field. I guess ill explain my setup first. my snes connects to my PVM through scart to bnc. My PVM has a splitter so it breaks out from bnc back to scart into a sync strike. I then capture the video with a vga cable out from the sync strike into my pexhdcap. I was having some sync issues with white flashes but I think I got that figured out. My problem now is I'm getting some really bad jailbars.

Heres an example: http://i.imgur.com/MlWTPl0.jpg

I think ive narrowed it down to my snes scart cable, the sync strike itself, or the vga cable im using. I connected my SNES directly to the sync strike into my cap card and I still get the jailbars. So its not my PVM or its cables. I'm waiting for a new vga cable and snes scart cable to come in the mail. Is there any way the sync strike could be causing this? Sorry im not very knowledgeable about this stuff. I really dont think its the snes scart cable because the Jailbars DO NOT appear on the PVM as far as I can tell. Someone did tell me that the PVMs arent as sensitive to jailbars though so who knows.

any one know whats going on? any help is very appreciated.

[RGB32E]

It's probably the particular HW revision of your SNES. What's the serial number of your SNES (UNxxxxxxxxxxxx)? Noisy RGB cables with the SNES don't cause that type of interference. Those types of artifacts can get masked on a CRT if they're not extremely pronounced.

[Jackafur]

It's probably the particular HW revision of your SNES. What's the serial number of your SNES (UNxxxxxxxxxxxx)? Noisy RGB cables with the SNES don't cause that type of interference. Those types of artifacts can get masked on a CRT if they're not extremely pronounced.

I have 2 SNES and they both do it. My fat model is UN 14400038. My snes mini has been modified to output RGB and its UC 206171436. The mini is a 1chip.

[Jackafur]

They actually inexplicably went away and then came back for no apparent reason

http://i.imgur.com/WsaU1Qc.jpg

i tried it on a 3rd snes as well. I dunno what the hell.

[Jackafur]

bumping this ancient thread hoping someone can help me with it. im debating on buying another one entirely. any one know of any fix for this?

[Skips]

Are you using a PEXHDCAP? If so turn the sharpness all the way down (to the right). If you set the sharpness too high stuff like this shows on the PEXHDCAP. Also, make sure you are using composite sync and not composite video as sync. Composite video as sync can cause this on some capture devices.

[Xaranar]

Resurrecting this ancient thread again, as I am experiencing the same issue on my RGB modded SNES Mini. I'm using the latest revision of borti4938's RGB amp, as detailed on his OSH Park page, with it wired for TTL sync levels as for some reason, the Framemeister doesn't like 75 ohm termination from my Mini. I never really noticed the pattern before a few weeks ago, as I bypassed the low pass filter on the THS7373 to see what it would look like, and the jailbars became very obvious. I don't know whether it has always been there, or it is a problem that has developed recently, as I did get a new monitor not long ago, much higher quality than the one I was using previously, and that may have helped to highlight the flaw. I don't know. Any ideas, anyone?

[RGB0b]

@Xaranar - This is something we're actually discussing in another topic. Try turning the LPF on the 7374 back on and see if it fixes the problem. Also, check your RGB SCART cable to see what components are on the sync line. It might be best to remove all components from the sync line (so it's a direct passthrough on that one pin) and set the board to 75 Ohm csync.

[Xaranar]

@retrorgb First of all, love your site buddy, I have gotten so much useful information from there, so thanks so much for that.

My SCART cable for my SNES doesn't have anything on the sync wire, but it does not deal well with 75 ohm termination. 75 ohm termination causes weird artifacting, like intermittent red banding across the screen, as well as the blue line sometimes dropping out randomly as well. I told borti4938 about this some time ago, and he suggested jumping the pads together where the 75 ohm resistor should be for the sync line, and it's worked perfectly since then, so with his latest revision of the PCB, his Github page actually gives you a choice of components to select whether you are wanting TTL sync or 75 ohm termination. Considering the trouble I had with 75 ohm previously, I opted for TTL and it worked brilliantly from the off.

EDIT:
I've just swapped out the TTL resistors on the board, and replaced them with the 75 ohm termination ones. I can confirm now that with this board revision, 75 ohm termination works just fine with the Framemeister. I think I will leave it that way for the sake of compatibility, so that if I ever get a CRT, I know 75 ohm will play nicely with it.

I also tried swapping the 7373 for a 7374 because the LPF on the 7373 is actually an HD one, as opposed to the SD one on the 7374, and yes, having the LPF on does indeed completely fix the jailbar problem.
Out of interest, where else is this being discussed?

[RGB0b]

Good call on switching the output to 75 Ohm csync. TTL into a framemeister may actually damage it over time.

Here's the link to the other thread. At the moment, I believe the only problem left to solve is how the filter on the FM works; Basically, with some firmwares, it's on and others it's off. The end goal is to only have one filter in-line, so for yours, it must be off on the FM: http://shmups.system11.org/viewtopic.ph ... &start=120

[Xaranar]

I don't think TTL does damage the Framemeister, even over time, it's pretty robust and not picky when it comes to sync types. Still, I'm sticking with 75 ohm termination csync now as it works perfectly fine as of borti4938's latest board revision, and it seems to eliminate the noise artifacts that Nintendo consoles seem to be very sensitive to.

I never have the LPF on the Framemeister switched on, I only ever use picture mode which completely disables it. The LPF on the 7374 is much better than the one on the 7373, however, so I would definitely recommend the former chip for a SNES mini amp.