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The DDC5V line is supposed to power circuitry in receiver which provides EDID so that transmitter can read it even if receiver is otherwise powered off. Neither OSSC or OSSC Pro relies on this as they don’t generally use the EDID. However, hot-plug assertion mechanism may also be reliant on the DDC5V in some receivers, so removing the fuse altogether is likely to result in total incompatibilty with some other displays. If modifying the receiver is not an option, then next best thing is to replace the SMD fuse with same-sized SMD diode, or preferably putting it in series with it. Leaving it as-is should be also relatively safe if 5V on receiver is well regulated.
On Scaler mode with 1x framelock, the latency should be a bit over 1 frame. With 2x framelock, average latency should drop to 0.75 input frames since top of the initial output frame still has 1 frame latency while bottom has 0.5.
With framelock off, there is an adder of 0-1 input frames and it fluctuates between that as there is no lock.
There shouldn’t be conflict of using HDR and VRR together, but keep in mind that VRR only sets the flag in metadata and does not vary vertical blanking, thus it’s currently more of a compatibility option.
Sure, you could add a diode to work around the issue if you’re familiar with SMD soldering. My point mainly was that it’d always better to fix the root cause, but it’s understandable if you want to avoid opening a plastic dongle that doesn’t have screws.
August 5, 2026 at 11:17 PM in reply to: No Picture on AV1 on Optoma Beamer with Denon Reciver #703740 ohms into selected line and infinite resistance to inactive inputs? The frontend chip is a graphics digitizer that is not designed for sources with bad sync quality which could explain difference to CRT or generic video converters. That said, it has been tested with various powered and unpowered switches without issues.
The Sobel edge deinterlacer needs more logic resources than what is available in current FW, but making an alternative image which cuts some other functionality to enable fitting could be an option. A second downside of it is reported deinterlacing latency (1 field versus couple lines) which however doesn’t make sense as it shouldn’t really need it. Perhaps it’s just a typo in datasheet so it’s something which would need to be measured.
It’s hard to count out the possibility of that OSSC being defective, but if it works with direct connection but not through a dumb mechanical switch, then at least I’d open and check the switch if it was my setup. Have seen enough bad scart switchers in my lifetime that only switch subset of lines.
Which output resolution and aspect ratio do you use? Under output opt. you also find “Adv. disp timing” where you can adjust output parameters. Typically it’s recommended to do the adjustments using the built-in test-pattern using the output preset you use in Scaler mode.
LM1881 typically just adds more issues than it solves unless connected exactly right. It’s futile to blame the switch without knowing its internals, but if you’ve tested various consoles through it without success then the issue can really be on the switch/connection or then the OSSC input is faulty.
Sometimes these kind of switches switch only a subset of lines and just connect others together. Maybe it’s a good idea to open it and check that all 9 lines are truly switched.
The polyfuse should trip easily if powered only via HDMI. You could add a diode but a better solution would be to just disconnect the pin on the capture device side as it clearly doesn’t need it
July 28, 2026 at 9:39 PM in reply to: 240p / 480i Modes in Pure-Line-Multiplier (P-LM) for OSSC Pro ?! #70290You need to use A-LM for 720p downscaling and it already has as low latency as such conversion can have. P-LM does integer-based multiplication/decimation for total amount of lines and standard 720p does not have exactly 3x total lines of 240p.
I also had a chance to probe the PSOne I mentioned, and in that case video & sync issues were caused by a bad 220uF cap on the PCB behind AV connector. Not sure if this is a widespread issue amon PSOnes, but if you have multimeter with cap tester function, it’s very easy to test it.
Is the linked switch perhaps using logic switches instead of analog multiplexers? Or maybe it’s mechanical if there is no power supply. If you have original AV cables for some of the consoles and RCA-scart adapter, you can try connecting that to AV1 and see if stable sync is at detected (picture is then blank).
It’s a known issue that has been fixed and will be part of 0.83 which is released soon.
July 23, 2026 at 8:14 PM in reply to: Request: Better support for MiSTer ao486 core in Direct Video mode #70240It looks like the core may not properly support direct video. Connected directly to my monitor or via HDMI->VGA converter to Pro produces no stable sync.
The garbage issue is now fixed and will be effective from fw v0.83. The issue with GB core seems to be that it indicates incorrect pixel repetition factor (2x instead of 5x) when menu is open.
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