Denon x3400h OSSC 480i passthru problem

[DarkRoastChris]

Hello all. I have come here from the shmups forum in attempt to continue troubleshooting a strange problem that I’m having with the OSSC and a Denon avr x3400h receiver in 480i passthru mode. Basically after quite a bit of testing I have narrowed it down to something the OSSC is doing to the 480i signal in passthru mode which the receiver doesn’t like.

The short of it is that when running the OSSC into the receiver and setting it to 480i passthru mode I get a horribly zoomed in picture with large black alternating lines that is completely unplayable. This does not occur when I change it to 480i 2x and 4x, I get a much more normal picture except for lower picture quality because of the deinterlacing. Now when I try the exact same setup with the Retrotink 2x in place of the OSSC and set it for 480i passthrough I get a perfect picture with nothing strange happening to the 480i signal while going through the receiver.

I have detailed results of my testing here.
https://shmups.system11.org/viewtopic.php?f=6&t=64747&p=1369676#p1369676

This is actually the same Denon receiver that Try from My Life In Gaming purchased and when I reached out to him he responded saying he had the exact same problem but forgot to mention it in their 4k video.

In an effort to keep the OSSC in my chain running into receiver I’m trying my best to nail down exactly what the OSSC is doing to the 480i signal in passthru mode that makes the receiver freak out. If anyone can give me some specs on the signal, suggestions, or direct me to the appropriate topic/forum that would be greatly appreciated. I’m open to trying anything within my power as it has basically become my mission to figure this out.

Cheers.

[marqs]

Can you try display test suite firmware (without any source), especially tests T3 and T4. Documentation for that firmware is found on wiki.

[DarkRoastChris]

I have run the test suite firmware.
In test T3 while running into the receiver instead of the normal greyscale bars that can be seen in the other tests and when you turn on the OSSC I got the greyscale screen but everything was heavily pixalated with jagged edges and was moving from the top of the screen to the bottom in a waterfall like effect. This was with all the receiver video processing options turned off. While still running this test I tried every video processing option on the receiver and while all of them did different things to the picture it was still what I would call a broken picture that never resembled the normal greyscale screen.
T8 produced no picture.
All other tests performed normally except the T2 and T4 produced a large checkerboard pattern at the bottom of the screen and none at the top but maintained otherwise normal greyscale bars.

I then tried all the tests with the OSSC running directly into the TV. All the tests produced the exact same results except for T3 in which I got a perfectly normal greyscale screen. This makes sense as whenever I run the OSSC directly into the TV I have no problems whatsoever.

Still kind of boggled as to what the receiver could possibly be doing with the 480i signal from the OSSC. Any thoughts?

[marqs]

At least that helps narrowing down the root cause. It might be related to IT6613E configuration or unsuitable HDMI Infoframe metadata, but it’s a bit strange that 576i doesn’t then have the issue. I’ll check if I can replicate this with my AVR-X2300W.

[DarkRoastChris]

That would be much appreciated. I’ve found everything about this issue with the 480i passthru and this receiver to be very strange. Also I know that the X2300W does indeed include a bypass mode in the video output settings whereas my X3400H does not. I have been wondering since the X3400H doesn’t seem to have that bypass option (only Auto, Game, and Movie options) that maybe it might be doing something to the 480i signal. If you could test it with the all the options including bypass then that would help me further narrow down the problem. I also have gotten an offer from another user on the shmups forum who owns a X3300W to help me test on his receiver and OSSC as well. His receiver also does not have the bypass option in the video output settings so depending on the results he gets that could help a lot as well.
Many thanks for all the help marqs.

[DarkRoastChris]

I have now run alot of my same tests as well as the test suite firmware on a Marantz NR1403 and it DID NOT have the same 480i passthru problem. It is quite a different receiver compared to the Denon but I wanted to see if this problem was solely with this Denon or Denon receivers in general.
Just a quick update.

[Gara]

Scratch my previous post. I screwed up the test.

I can’t seem to get 480i from the OSSC or Time Sleuth to output through the Denon 3500h. 480i from my DVD player works fine. The receiver likes to re-enable video processing on 480i sources. Once I disabled it a second time it results in no signal for the Time Sleuth and the OSSC.

That weird effect I was getting on Crazy Taxi was a result of the receivers built in processing.

I took the Denon out of my chain and that solved the problem for my setup. I’d like to be able to use the Denon. I wonder if there is something we could adjust in the OSSC that would make the signal more tolerable like my DVD player.

I have this same problem with my Denon 3500h. This is what it looks like:
Dreamcast Crazy Taxi title screen 480i via the OSSC

Ossc 480i Denon 3500h

576i from DVD sources via a BD player display fine. So does the 480i time sleuth test pattern.

All video conversion settings are off. The Denon adds no lag on 480i according to the time sleuth, so there shouldn’t be any hidden processing going on. All video conversion settings on the Denon are off.

I’d be delighted to be able to add my ossc back to the Denon chain. I worked around the issue by using ARC, but it makes my setup a bit more convoluted.

[Gara]

I updated my post. I messed up the initial test. There is something about 480i that the Denon can’t pass thru. Maybe there is something in the OSSC settings that can be adjusted? It seems to like 480i from DVD sources just fine.

[marqs]

I tried my AVR-X2300W with the display suite firmware and the results were interesting. In AVR bypass mode, 480i resulted to no signal (576i was ok) but with Denon’s scaler enabled, 480i was displayed correctly. This needs some investigation. One different thing with DVD 480i sources is that they use YCbCr mode instead of RGB, perhaps you could try YCbCr444 TX mode in the most recent fw. I’ll see next if it makes any difference if some Infoframe parameters are tweaked.

[DarkRoastChris]

Now that is interesting. Any time I have tweaked with the Denon X3400H scaler while using the OSSC it does change the picture I’m getting but has not come close to what I would call a correct picture. I would have thought that using the bypass mode was the key but apparently not. Still bugs me that both mine and Gara’s Denon do not even contain that option but according to Gara the time sleuth seems to suggest that it still is not doing any extra processing.
I have tried the YCbCr444 TX mode as marqs suggested and it still creates the heavily pixalated, jagged edge image with the waterfall effect that I mentioned earlier. I also tried every option on the receiver while in this mode and while some of the scaling options got rid of the pixalated waterfall look, it still was massively zoomed in with the black alternating lines. Also whenever I turn on Game mode in the receiver it alters the colors in the picture to almost a negative look but not quite that degree. Alot of interesting things going on with this receiver.

[marqs]

I tried a few things with AVR-X2300W and it seems to require Video Information Code (VIC) explicitly set for interlaced sources to be displayed properly or at all. By default OSSC sets the code to 0 (“unknown”) since in most cases resulting video timings do not exactly match CEA spec. After setting VIC to 6 (480i60), 480i thru Denon displays OK and other modes cease to work.

[DarkRoastChris]

That seems like an oddly specific and cumbersome thing for the Denon to require. Is there a way to adjust something within the settings of the OSSC that would allow me to set the VIC to 6? I have been through the options a few a times and don’t see anything that looks like it would allow me to change that.

[Gara]

My apologies, DarkRoastChris. I screwed up that first test with the Time Sleuth. I wasn’t able to actually test the Time Sleuth through the Denon with video processing off. It reports no signal like the OSSC with 480i through the Denon. The TS works fine with 480i when directly connected to my TV.

Is VIC something user configurable and/or a setting that profiles would support? I’m not familiar with that setting.

[marqs]

It should be possible to automatically select a suitable VIC based on some conditions. I created a test firmware which assigns explicit VIC in passthru mode for well-known input modes.

[DarkRoastChris]

Ok so I’ve updated the firmware and first impressions are very good. I have the OSSC running into the Denon on 480i passthru and the picture is no longer a complete mess. It seems to be a normal 480i picture and when I switch the Denon to Game mode I no longer get the weird color distortion. I will continue playing some different games and consoles to see if there is any other abnormalities but as of right now I am very happy with what I am seeing.
Gara I recommend that you try out the firmware for yourself and see if it fixes your problems as well.

A huge thank you to marqs for the all the help and support. The OSSC is an amazing invention and I am super happy to be able to put it back into my setup.

[Author]

Posts