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Possible image rotation to the analog output?

Posted: Wed Jan 12, 2022 12:55 pm
by FeelsDuckMan
Would it be possible to add the image rotation to the analog output? It'd be nice to play the vertical arcade SHMUPSwithout having to flip my crt to its side. Is this something that can be done feasibly?

Re: Possible image rotation to the analog output?

Posted: Wed Jan 12, 2022 3:09 pm
by FPGA64
No its not trivial. You would have to introduce a framebuffer and hence lag. Real arcades simply turned the monitor on the side. If the game dipswitches dont support rotation then you are out of luck.

Re: Possible image rotation to the analog output?

Posted: Wed Jan 12, 2022 3:19 pm
by FeelsDuckMan
FPGA64 wrote: Wed Jan 12, 2022 3:09 pm No its not trivial. You would have to introduce a framebuffer and hence lag. Real arcades simply turned the monitor on the side. Iif the game dipswitches dont support rotation then you are out of luck.
Alright, understandable. Thanks.

Re: Possible image rotation to the analog output?

Posted: Wed Jan 12, 2022 7:29 pm
by HappehLemons
It’s actually pretty easy, and in my experience there is no noticeable latency.

viewtopic.php?f=33&t=3527

The one thing preventing it is there seems to be a bug with MiSTer that cuts off a small portion of the right side. Not sure if its been fixed. Someone should file a github report so it will get the proper attention if this still exists.

Re: Possible image rotation to the analog output?

Posted: Wed Jan 12, 2022 8:08 pm
by FeelsDuckMan
HappehLemons wrote: Wed Jan 12, 2022 7:29 pm It’s actually pretty easy, and in my experience there is no noticeable latency.

viewtopic.php?f=33&t=3527

The one thing preventing it is there seems to be a bug with MiSTer that cuts off a small portion of the right side. Not sure if its been fixed. Someone should file a github report so it will get the proper attention if this still exists.
Oh wow, thanks for this tip! I hope the issue gets resolved.

Unfortunately I don't know the technical issues causing this and I don't want to file a report and give misinformation. I'm not really sure how those scaler numbers in the INI even work.

Re: Possible image rotation to the analog output?

Posted: Wed Jan 12, 2022 9:41 pm
by HappehLemons
FeelsDuckMan wrote: Wed Jan 12, 2022 8:08 pm
HappehLemons wrote: Wed Jan 12, 2022 7:29 pm It’s actually pretty easy, and in my experience there is no noticeable latency.

viewtopic.php?f=33&t=3527

The one thing preventing it is there seems to be a bug with MiSTer that cuts off a small portion of the right side. Not sure if its been fixed. Someone should file a github report so it will get the proper attention if this still exists.
Oh wow, thanks for this tip! I hope the issue gets resolved.

Unfortunately I don't know the technical issues causing this and I don't want to file a report and give misinformation. I'm not really sure how those scaler numbers in the INI even work.
I don’t think many people do (including myself) I just know that video mode “works” :)

If you don’t care about proper screen ratios, that above works without any cut-off if you play the games in full screen to fill the width of the TV.

Re: Possible image rotation to the analog output?

Posted: Wed Jan 12, 2022 11:08 pm
by Grabulosaure
This is a know limitation of the scaler.
When using the framebuffer mode, which is the case when rotating arcade cores, the scaler cannot downscale properly.

- Latest changes, not yet applied on all cores, can do some form of vertical downscaling. It's not perfect as some lines are skipped, but at least the image should be complete.
- Horizontal resolution can be raised for on the analog output so that the scaler never need to downscale horizontally.