For starters, most information will be on the OSSC’s wiki page here: http://junkerhq.net/xrgb/index.php?title=OSSC. If you want to know what a setting does, you can read about it there; and, if it doesn’t make sense or is too technical, you can just leave it at its default value.
I pressed the linemult mode button and chose number 5 and it worked so that means it’s outputting 1080p right?
The default for this is 1920×1080 progressive, so yes (unless you’ve mucked with this setting). The Line5x format setting can also be set to 1600×1200 or 1920×1200 for 4:3 and 16:10 displays respectively.
I’ve found the menu settings slightly confusing – just left the LPF on Auto and it seems to do the best job as far as noise is concerned but there appears to be some noise coming through on backgrounds with a fixed colours – almost like diagonal lines that are faint in the background and I feel like they shouldn’t be there. I turned my HDMI input on my TV to game mode (no noticeable lag for me!) and turned off every other useless setting and overall I am really happy but I feel it could be tweaked a little – my confusion comes in the form of the other options which just seem to mess with the colour so I’ve left them as they were really. Are these the settings that can help eliminate the lines I’m seeing? If it because it’s a 4k TV outputting 1080p?
Are these diagonal lines static, or do they move?
Someone more knowledgeable can chime in, but video noise like that is typically from poorly-shielded cables or noisy/crap power supplies. If I remember correctly, SCART cables for the SNES and GameCube use composite video for sync, and a poorly-shielded CVBS line can interfere with the RGB lines. Poorly-shielded audio lines can also cause and receive interference (audio buzz).
While it’s possible your TV’s upscaler is causing the diagonal interference, I think you can either confirm or eliminate the TV as a problem if you can try your SNES+OSSC on a different TV.
Now I expected the overscan when playing games, I did read about that but I wondered if the image could stretched or manipulated in some way to get rid of the boarders on the sides that obviously weren’t meant to be seen?
The OSSC is incapable of stretching or any real manipulation of the image; however, the OSSC can add a horizontal and/or vertical mask of up to 63 pixels. This mask basically just blacks out the configured number of pixels from the left/right sides and/or the top/bottom. Do note that this will effectively letterbox the image on your display, and, if that’s a problem for you, you would need to use either your TV’s zoom function or another video processor.
My other question is on the display is says 312p – shouldn’t it be 240p? The resolution thing also confuses me. Basically I am rubbish and I don’t know anything!
This still throws off people now and again, and I periodically forget about it myself. The OSSC displays the total number of lines in the frame, but not all of these are visible (some are used to encode metadata). Interlaced NTSC frames have 525 lines, of which 480 are visible; and interlaced PAL frames have 625 lines, of which 576 are visible. Halve that for non-interlaced, and the OSSC will display 262p for NTSC (240p) and 312p for PAL (288p?).
Hard to see the lines I talked about but look at the top right of the image, the yellow bit and you may see some darker diagonal streaks instead of just the one colour throughout – if you can see them, can they be smoothed out so to speak?
You can try playing with the Video LPF setting in ‘Video in proc’, but Auto should be correct.