PiCapture › Video rolling on some inputs
September 24, 2016 at 8:11 pm #718
I’m back again with another problem.
On certain video inputs the signal “rolls” vertically. In my case I can reproduce it with older Nintendo systems such as an SNES or N64 using composite. It does not occur with a more modern system such as an Xbox 360 through composite.
I’ve attached a video of the behavior on an N64. https://youtu.be/Y63e_jCuiSY
In this case the N64 is connected via a composite input on Video1. I’ve heard of similar issues with the N64 rolling on certain monitors before so I don’t think it’s unique to the PiCapture.
In my case, the PiCapture successfully identities the signal as NTSC so I don’t think the most common PAL/NTSC conflict is the cause in this case.
The N64 outputs can output at various resolutions such as 240p (320×240), 288p (384×288), 480i (640×480).
I didn’t find anything in PiVideo that might allow me to tweak some settings to get around it.
Do you have any ideas on how I might be able to resolve this or identify where it’s going wrong?
JoeSeptember 24, 2016 at 8:44 pm #719
Thanks for the video, Joe. Is the N64 set for 480i video output?
We haven’t seen this before, but I’ll look into it and see if I can come up with a solution.
MarshalSeptember 24, 2016 at 8:51 pm #720
Unfortunately with an N64 or SNES there is no way to change the output resolution. I guessed that it may be a resolution problem but I’m not sure there is anything I can do on my side to work around it.
JoeSeptember 25, 2016 at 2:12 pm #721
Joe, I’ve done some research on the video output for the N64, and it appears that most games for that console generate 240p video. The console itself apparently has other capabilities, but for performance reasons (I read!) they aren’t generally used and it isn’t something that can be changed. Unfortunately, the SD1 can’t handle 240p video without some changes.September 25, 2016 at 2:24 pm #723
Thanks for checking!
Are you planning on supporting other resolutions?
A lot of older consoles (NES, SNES, N64, Master System, Genesis etc) output at odd resolutions and having support for those would open up a lot of possibilities for the SD1 (such as gameplay capture, upscalers etc).
Would hardware changes be required or is it a firmware issue?
September 25, 2016 at 2:44 pm #727
- This reply was modified 4 years ago by Joe.
From the video that you posted, it appears that 240p is “close” to being handled. It is getting through the video decoder (which is surprising to me, because it isn’t a supported format according to the documentation), but is confusing the deinterlacer. My guess is that it could be supported with an FPGA change if there is enough demand – I appreciate the suggestion!September 25, 2016 at 2:58 pm #728
That makes sense. Let me know if you decide to add support for 240p in future!
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