Unseen wrote:meneerbeer wrote:I am trying out the p2x code. I get a red screen. Most likely something is wired up incorrectly, because I have the idea to yuv to rgb is always active?
Yes, since the p2x outputs a DVI signal it has to convert the output to RGB.
Currently looking what is going wrong, but perhaps you have an idea, Unseen?
My first guess would be something wrong on the input side because as you mentioned the colors do look more like YUV problems than RGB problems. Since there is a stable picture, at least Clock, VData 4 and VData 5 are connected correctly (HSync/VSync, muxed within the pixel data). CSel might be involved in the problem, but it would be connected to a wrong signal and not just open or shorted to ground/supply. Another possibility could be a mis-wiring of the highest VData lines (6/7) so that it is seen as constant/mostly-constant 1 during the picture area, although it can't be miswired to the adjacent 3.3V pin because then you wouldn't get a picture at all (all-zero Y component is used to mark that the cube is transmitting Sync+Flags instead of picture).
If you want to check that it's not a problem of the board, you could try to flash KNJNs Pong demo from the StartupKit zip, subfolder "FPGA project - HDMI". It doesn't matter if the board is connected to the cube or not to run that demo, choose the method that is more convenient for you.
(which reminds me that this might be a good test for andre104623's board too...)
Ouch, quite a long post, when it was just me flashing the wrong file.. Sorry about that.
I have made a custom PCB, which is why I had to modify the code. I uploaded an album with some images
here. I still need to get screws with ring nuts to secure it better. Right now I just took two screws from the DVD drive and stuck them through to at least keep it a bit in place. Also, I kind of screwed up the opening for the HDMI connector..
Everything seems to work fine. Some games look really good (Smash Bros and Mario Kart for instance). Other games do not really look that great. In Wind Waker I notice a pattern with stripes. My guess is that this is normal (dithering?). With analog cables I suppose you do not really notice this. It looks kind of bad though. I added a zoomed in image of Wind Waker to the album, so you can see what I mean.
My GC is PAL and not modded, so I can only try interlaced video modes. Interlaced video over HDMI works great for my TV luckily. I am eager to try out true 480p and 576p. If you go as far as doing this mod, it is a bit stupid to only use interlaced video.
I tried out the line doubler. It seems to give a "jumpy" image. As if every other frame the image jumps down by one line. It definitely happens at the top and bottom line, but I have the idea that the whole image is jumping up and down. I think this can be fixed, but then we first need to be certain about what causes it.
Scanlines are working great for me for linedoubled 576i. For linedoubled 480i they are barely noticeable. They only seem to be noticeable when there is movement on the screen. I think this also has to do with the above issue with the jumpy image.
I do not really care too much about the linedoubling issues, since I do not really plan on using it.
Oh, one other thing. It seems you do not set the active video you send over HDMI as 720x480/720x576. Perhaps some TVs get confused by this because they expect a line to have 720 active pixels (that will give black bars). Although it is definitely not the problem that is causing the p2x to not work with so many TVs.
Other than that, it is really nice. I would have never put this much effort into it. I probably would have only decoded the video signal to HDMI and been too lazy to add all these features.