RAD-2X Upscales Composite to 720p but RGB to 480/576p?

[NewSchoolBoxer]

I was in a Reddit thread trying to help someone whose Samsung QE49Q60R (4k Smart TV) accepts N64 Composite -> RAD-2X -> HDMI but not from their Tim W RGB modded system. Could say mod was done wrong but modder tested and showed picture proof of it working.

Well, p. 164 from the television's manual shows it accepts HDMI at 720p at or higher. Not surprised at lack of 4:3 above 1080p. Component at 1080i as well: https://downloadcenter.samsung.com/cont ... 1026.0.pdf

RAD-2X: Output: miniHDMI at 480p/576p (line-doubled mode)
https://www.retrogamingcables.co.uk/RAD ... HDMI-CABLE

My interpretation is Smart TV fails to accepts 480/576p exactly as its manual states but RAD-2X upscales Composite to 720p or better and fails to disclose this.

Do you own a RAD-2X or similar 4K Smart TV?
a) With RAD-2X, can you use Composite to RAD-2X on a 240p system to verify what the output resolution is?
b) On Smart TV, can you use a PS3 or Xbox 360 to switch between 480/576p and 720p to prove 480/576p is rejected?

For a plug & play product promoted for this very reason, seems to be a big failure not mention to check that your TV actually supports 480/576p. If Composite->HDMI is at 720p, I can understand failure to disclose from a marketing gimmick. If an HDMI TV accepts 480/576p, it would accept 720p too and don't want to give the illusion that Composite is better.

Interesting to see the use case explained for RAD-2X for another similar 4K Smart TV with HDMI only inputs, the Samsung UE49MU7000. From the Retro Gaming Cables website that sells the RAD-2X: https://retrogamingcables.co.uk/How-to- ... s-via-HDMI
I'll save you the manual link but it's the same formats as the first Samsung so no 480/576p. Too bad article doesn't disclose if Composite and/or RGB was used.

[Guspaz]

TVs that won't accept 480p over HDMI are exceptionally rare (I've never even heard of one existing), and the Samsung QE49Q60R is no exception, it does support 480p over HDMI. The RTINGS review shows 480p input (among other resolutions). I've never even heard of a TV that does not accept 480p over HDMI, and it seems far more likely that that TV doesn't like the exact timing than it not liking the resolution.

The RAD-2X and RetroTINK-2X products do not support line tripling, and cannot output 720p for any 240p/480i input.

[NewSchoolBoxer]

Thank you for your input and specialized knowledge! I read the RTINGS review and indeed it shows 480p working. However, that was likely from a 100% in-spec DVD player outputting 480p at a constant NTSC 29.97 fps. Here we like retro consoles and nearly all of them have out of spec video output with variable lag that reduces the framerate. The poster was using an N64, which runs at ~10-60 fps with 20 fps cap being typical, and I could see a modern television maker not testing such an edge case.

I dumped "480p not work on 4k" into Google and found 2 results. First result is a 4K Sony KD-55XE7096 not accepting 480p via Xbox to HDMI with generic converter, even though the manual shows 480p support.

Second link is about a 2018 Samsung 4K TV not accepting 480p from Xbox + Microsoft-licensed Hyperkin Panorama HDMI converter, even though the signal works on "old junky 720p TV".
Comment from another user says PS2 to HDMI works for 480i but not 480p but PS3 480p and a SCART converter with HDMI passthrough work. (no TV details given)

So I think as time goes on, 480p support on modern televisions will get shakier and shakier, with DVD output safe for now but not from retro consoles. I don't think leaving 480/576p out of the manual was an oversight.

Beyond what I was asking but I'm curious how the RAD-2X handles Pokemon Stadium 2 that runs at 480i except 240p during battles. Or PS1 Chrono Cross that is 240p except (infamously) 480i during menus.

[Guspaz]

Consoles always send out frames at a fixed interval, regardless of the rendered framerate. Variable refresh rates only became a thing with the Xbox One generation of consoles.

[GrimShins]

TVs that won't accept 480p over HDMI are exceptionally rare (I've never even heard of one existing), and the Samsung QE49Q60R is no exception, it does support 480p over HDMI.

480p support is mandatory per CEA-861, so the TV wouldn't even be able to advertise itself as HDMI if it didn't.

[mikechi2]

Man, there is so much misinformation here

1. RetroTINK-2X devices can only line double to 480p, or else I'd be marketing the crap out of the 720p capability.
2. As others have mentioned, 480p is the mandatory baseline resolution per the HDMI standard and won't be disappearing. Newer 4K TVs thankfully appear to be far more tolerant than before of weird retro stuff and non-spec timing, so I'm hopeful for the future.
3. N64 games may render at lower frame rates. Output, however, is a constant ~60 fps, or else even your CRT couldn't sync to it.
4. If the RAD2X worked over composite on a given TV, then that TV is perfectly happy accepting the video timing of the line doubled N64 video. Problem is either with the mod or the RGB input on the RAD2X is broken. There's no conspiracy.

[fernan1234]

3. N64 games may render at lower frame rates. Output, however, is a constant ~60 fps, or else even your CRT couldn't sync to it.

Or, to be a bit more precise, 60Hz refresh rate.

And on the TC's issue, I'd sooner suspect some setting on the TV side making the R2X's input be processed and displayed as if it were 720p.

[NewSchoolBoxer]

We got the legendary Mike Chi in here, nice.

Newer 4K TVs thankfully appear to be far more tolerant than before of weird retro stuff and non-spec timing, so I'm hopeful for the future.

That's good news, I was suggesting the reverse to be true but then I've never used a 4K/8K device myself. So N64 lagging wouldn't throw off ~60 Hz output, also good to know.

Standards change over time. 1080p Component died out with the rise of HDCP. That an "HDMI" branded television has to accept 480p, thank you for the heads up! Issue is the codified official television video formats are all locked behind pay walls and DMCA threats. I did find the Consumer Technology Association's CEA-861-E from 2017 that I have a right to review and quote from. 480p (and 576p) is supported at very specific sync and EDID timings. Page 27 lists Video ID codes and resolutions. Sorry I have no table making skills in BBS:

VIC | Formats | Field Rate | Picture Aspect Ratio (H:V) | Pixel Aspect Ratio (H:V)
1 .... 640x480p ... 59.94Hz/60Hz .................... 4:3 ........................... 1:1
2 .... 720x480p ... 59.94Hz/60Hz .................... 4:3 ........................... 8:9
3 .... 720x480p ... 59.94Hz/60Hz .................. 16:9 .......................... 32:27
14 ... 1440x480p . 59.94Hz/60Hz ................... 4:3 ........................... 4:9 or 8:9
15 ... 1440x480p . 59.94Hz/60Hz ................... 16:9 ........................ 16:27 or 32:27
35 ... 2880x480p . 59.94Hz/60Hz ................... 4:3 ........................... 2:9, 4:9, or 8:9
36 ... 2880x480p . 59.94Hz/60Hz .................. 16:9 .......................... 8:27, 16:27, or 32:27
(rest of 480p entries have field rates > 100 Hz)

So video output from console not at 320x240p, 360x240p, 720x240p or (lol) 1440x240p before line doubling can be rejected outright. N64 has plenty of wonky resolutions. Maybe the built-in Composite video encoder stretches to 320x240 but RGB mod uses a THS amplifier that does not. Best test would be unmodded SNES with its wonky resolutions + its 60.10 Hz "field rate" on a comparable Samsung Smart TV. I'm sorry to Mike and others than I have to speculate on all this, lacking the device and Smart TV. I want the answer and 4K/8K TVs rejecting formats that older ones accept is a new frontier.

I see another potential issue being (Component) YCbCr compatibility. RAD-2X transcodes (analog) RGB to (analog) YPbPr then to (digital) YCbCr over HDMI yes? Not sure of the sampling rate. The document covers YCbCr 4:4:4 and YCbCr 4:2:2 in great detail but no mention of YCbCr 4:2:0. The 4:2:0 sampling is prolific for streaming, if not also Blu-ray, so not sure how to interpret the lack of but 4:4:4 and 4:2:0 have to:

set both bits 4 and 5 of byte 3.
NOTE—The HDMI specification requires this behavior.
A sink that does not support YCBCR pixel data shall have both bits 4 and 5 clear.

I'd think easy to verify from the HDMI encoder chip datasheet what it's doing with YPbPr input.

And on the TC's issue, I'd sooner suspect some setting on the TV side making the R2X's input be processed and displayed as if it were 720p.

That's a good point. We hate on EDTVs and LCDs for interlacing 240p to 480i and losing scanlines. I can imagine modern TVs upscaling 480p in ways not friendly to retro gaming consoles.

[Guspaz]

1080p component never died out, it never existed in the first place. The standard maxes out at 1080i, regardless of what is technically possible. Analog video signals do not have a horizontal resolution, it's just about how fast you modulate the signal on each line, and that doesn't have any impact on the analog video timing. This is why pixel-perfect sampling is so incredibly difficult.

[Extrems]

1080p component never died out, it never existed in the first place.

You sell cables that advertise this as a supported resolution, which is indeed output by the relevant consoles.

[GrimShins]

Somewhat of a non-sequitur, but man it stews me that CEA claims that the pixel aspect ratio of 720x480 is 8:9. If you do the math, the true PAR is 10:11, which would result in a square pixel resolution of 656x480*, not the 640x480 that 8:9 would imply. As a result, every device that complies with CEA spec is displaying square pixel 480i/p too narrow. 8:9 would be the proper PAR for 704x480, but that's not a standard resolution in the spec. Brilliant work, authoring a standard that ensures anyone following it will produce distorted images!

*Well, 654.545454... but let's go with a mod16 number to make things easier.

[fernan1234]

Somewhat of a non-sequitur, but man it stews me that CEA claims that the pixel aspect ratio of 720x480 is 8:9. If you do the math, the true PAR is 10:11, which would result in a square pixel resolution of 656x480*, not the 640x480 that 8:9 would imply. As a result, every device that complies with CEA spec is displaying square pixel 480i/p too narrow. 8:9 would be the proper PAR for 704x480, but that's not a standard resolution in the spec. Brilliant work, authoring a standard that ensures anyone following it will produce distorted images!

*Well, 654.545454... but let's go with a mod16 number to make things easier.

Something definitely went wrong when they tried to standardize SD and ED TV content for fixed pixel displays when transitioning to the digital era. I've found that feeding 480i/p via HDMI into most monitors will make them display it at the reported 720x480, which is actually wider than what it would look like on a 4:3 CRT with little to no overscan. When some kind of "aspect correction" option is available for SD/ED signals, it ends up being too narrow as you mention. The sweet spot is somewhere in between.

[Guspaz]

1080p component never died out, it never existed in the first place.

You sell cables that advertise this as a supported resolution, which is indeed output by the relevant consoles.

You're right, I had only been looking at the CEA standards and ignoring the SMPTE standards.

[Extrems]

It's not just SMPTE either.
https://www.itu.int/dms_pubrec/itu-r/re ... !PDF-E.pdf