Aspect Correction for 480i and 480p

NewHome Forums OSSC & OSSC Pro OSSC – Feature Requests Aspect Correction for 480i and 480p

Viewing 3 posts - 1 through 3 (of 3 total)
  • Author
    Posts
  • #25069
    Cae
    Participant

    I’m not sure whether or not this is possible, but I figured it must be worth asking. So, I have my OSSC hooked up to a computer monitor, a setup that I imagine is somewhat common due to compatibility, but one issue with this setup is that most monitors, mine included, will only display the image in either a natural square-pixel aspect ratio or the aspect ratio of the display. In particular, this means I haven’t found any satisfying way to display 4:3 480i/p sources in the correct aspect ratio. I’ve basically tried three ideas without much success: (1) using the advanced timing tweaker to downsample 720×480 to 640×480, which leads to lost detail and extra blur, (2) using “allow upsample2x” along with other settings to achieve 1280×960 output, which looks oversharp and unnatural to my eyes, and (3) increasing the horizontal active area without upsampling to achieve 960×480 output, which simply doesn’t work.

    That third idea was actually the first thing I tested, but I mention it last because it’s the one I want to ask about: is there any way that could be made to work through a special mode in a future firmware update? To reiterate since I didn’t explain it fully the first time, the idea is that the OSSC outputs 960×480 signal containing a 720×480 active area with black bars on either side. Whatever the exact numbers, as long as the active area fills 75% of the output signal on the horizontal axis, a display could then scale the output from the OSSC to 16:9, resulting in the inner active area being scaled to 4:3. I think I understand why this doesn’t work via advanced sampling tweaks, but there are already a few particular OSSC modes that effectively add black bars outside the active image area for 240p (240px3 in Generic 4:3, 256×240 optimized mode with 8:7 aspect, certain configurations of 240px5), and I have sort of a vague notion that these all work through some sort of unconventional trick. That’s why I’m unsure of whether or not what I’m suggesting is possible, as implementing it would likely require some sort of creative workaround, which I wouldn’t know enough to come up with. But if it is, in fact, possible, then hopefully I’m not the only person who would benefit from such a mode.

    #25070
    nmalinoski
    Participant

    Does the aspect ratio actually need to be adjusted, or would windowboxing to a given resolution produce the same effect?

    If not, you might need to invest in a new display that has proper aspect ratio controls. Normally, SD and ED modes, as well as anamorphic widescreen, are supposed to be stretched by the display (non-square pixels and all that).

    #25072
    Cae
    Participant

    I don’t understand your question. My idea is to have the OSSC add pillarboxing, not windowboxing. As is, when the OSSC is outputs 720×480, my monitor can display that in either 3:2 or 16:9. The image needs a bit more pillarboxing than the display can add to get to 4:3. I’ve already tried buying a new monitor with proper aspect control built in three times now, and every time there’s been something wrong with it and I ended up having to return it. It’s very frustrating. Only a handful of brands offer that functionality in monitors, so there’s not a lot of options there anyways.

Viewing 3 posts - 1 through 3 (of 3 total)
  • You must be logged in to reply to this topic.