The sync problem exists at the OSSC. Putting the OSSC first in the chain defeats the purpose. The GBS handles the sync better, and "smooths" the signal before going to a the OSSC, which is ultimately only the chain as an expensive Component-to-HDMI converter. But I already own it, and I'm not going to spend more money on a purpose-built converter.Shiver_169 wrote:The option you present is very interesting, but tell me what would be gained by chaining these 2 devices? I would think that the correct order would be OSSC and then GBS Control, especially for cases like SNES where framerate is a problem for many TVs and I think that with GBS Control this could be improved. And I have not wanted to buy an OSSC given its compatibility problems in resolution and framerate with many TVs on the market. And changed a little the subject you can pass us photos and model of your transcoder from VGA to YPbPr, I am looking for one for Dreamcast since VGA is quite problematic in my Setup it is the only console with this output and it is a problem for me.NoAffinity wrote:So, I wanted to revisit chaining the GBS w/ rama firmware to OSSC, for a specific use case.
Playing Neo Geo MVS on a Retrotek supegun (yes its cheap, but it works...pretty well)->SCART->OSSC, I optimized the OSSC, got it looking great, but would get infrequent momentary audio drop-outs. The MVS is known to need a bit of extra tuning w/ OSSC via 'H-PLL Post Coast' and 'HSync tolerance' tweaks. I'm attributing it to either a related tolerance mis-match, or something else unknown that isn't quite aligned with the MVS' output.
So, I tested the chain of:
MVS 1-slot -> Retrotek Supergun SCART output -> GBS-8200 w/ rama firmware, VGA output -> VGA-to-YPbPr transcoder -> OSSC YPbPr input
The GBS is set to 1280x1024 output, so OSSC is treating it as pass-thru.
I tested:
1) OSSC @ default settings, with minor tweaks to H. Backporch and V. Backporch to center the image
2) OSSC w/ attempted optimization
In the capture, the image ratio appears to be about comparable between both settings. On my flat panel, the optimized image is more compressed, much closer to what I assume is native 1280x1024.
Either way, it looks pretty darn good, and most importantly, no audio drop out.
And there was some recent questions about chaining GBS w/ rama firmware -> OSSC, so hear you go:
https://youtu.be/XAmvp0XqhoE
And here's a direct download link of the original video file: https://we.tl/t-4H5blxp2HD
I tested GBS @ pass thru this morning, sending 240p to the OSSC. Using my stock "MVS direct" optimizations, with a few minor tweaks, I got it looking every bit as good as if the GBS isn't in the chain, but again, with the benefit of eliminating the drop-outs.
The VGA-to-YPbPr transcoder I have is the Retrotek model: https://www.retrotekshop.com/products?pn=VGACTV2