HDMI vs USB-C video

Greetings!

Has anyone done a picture quality comparison between PPM’s usb-c (video) and hdmi ports? Is there a difference between the two? There’s been multiple official mentions about the HDR10 working over the usb-c port, so there should be a better quality that way. Could somebody post experiences about this?

I think the best way to do the comparison is to use a source like a laptop which has both hdmi and usb-c video ports. I would do this my self but my PPM is still somewhere on the way.

Thanks!

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Hi @Lovehardo
Welcome to this forum.

As said by @wernerj in this thread (HDR via USB C and what type of USB C) :

  • there’s no difference between HDMI and USB-C picture because the video signal from USB-C is routed through HDMI inside the PPM.
  • apparently, no HDR handled by the PPM (@wernerj, have you more explanations about this ?).
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Hi @Lovehardo the USB-C input accepts 10-bit colour, the HDMI only 8 bit. But practically speaking it won’t make much difference in viewing experience, specially if you have white walls.

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That’s interesting, is it still 10-bit after being converted back from DP to HDMI internally? I was under the impression that the V92 chip might only advertise 8-bit capability - but that may of course be different on the different inputs.

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There is no such conversion if I interpret this post correctly:

There is indeed one of those chips inside after all:

I have a few posts to amend. I thought I’d wait until I received my PPM and could verify myself this time around :slight_smile: (still waiting for German customs in the “April 10” shipment so it’s going to be a few more days)

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I’m confused now too. Hopefully you’ll get yours next week or so and can verify all this.

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Hopefully HDMI will be gradually replaced by USB-C video, while it served it’s purpose and was a much simple way to connect compared to component videos and separate audio, I’ve never been a fan of the HDMI plug it’s just too loose and easy to lose contact and connection

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I agree. The same issue that the unfortunate European “SCART” connector suffered, the cables are typically too heavy for the connectors to fully support, leading to failures.

USB-C video will hopefully see an increase when USB4 takes off. It requires some more logic than a standard “dumb” HDMI port, but silicon to handle the difference is getting cheaper and cheaper. There’s a lot of focus on DisplayPort in concert with USB4 though, so not sure how HDMI as such (despite the HDMI alt-mode) will fare.

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Ha It’s funny that you brought up SCART, now it’s come full circle, I had a Phillips tv in the early 90’s with a SCART connection on the back which was not common in Australia, and I had to look around for a SCART to RCA adapter so I can hook up my SuperNintendo at the time, none of the major retailers had it, did end up finding it in a proper electronics store so I was able to get clearer video as well as actual stereo sound on my games instead of using the regular RF connection most settled for, for which I was super happy about.

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Wow, never imagined SCART to ever appear anywhere outside Europe, very interesting!

Yeah SCART had some really nice stuff going, like real RGB and fast blanking (when available) that initially was designed for external Teletext decoders (also ancient :)). Then somebody agreed to abuse the red RGB signal turning it into Chroma for S-video and making way to many combinations possible. Kind of like USB-C today!

As the US equipment mostly used BNC for composite video as the only alternative to RF until S-video and component video came around the European SCART was the best connector available, but the number of those connectors I have had to re-solder back into the mainboard of TV:s and VCRs during the years - brrrrr, don’t want to think about it! :wink:

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Hi folks and thank you for the answers and an interesting conversation!

I’m trying to do two things, maximize the picture quality of PPM (10 bits are more than 8 bits, aren’t they) and minimize the excessive need of plastic stuff in this burning world. And this time I can get both!?

My laptop, phone, bluetooth earbuds and bluetooth speakers all use usb-c, so I was (and still am) very excited when I saw that PPM would too. I was even more excited when I noticed the official updates stating that HDR would work through usb-c (and on internal apps).

In an utopia, I would only have one multiport charger and three usb-c cables in my pack and would still be able to produce HDR video and a quality sound wherever I travel. I’m getting pretty damn close to that utopia. :slight_smile:

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Hi all and @PhilipsEngineering,
Thank you for the discussion on this topic.
I’m still waiting for my PPM so I wonder: do we have any ideas about the input lag for USB-C and how it compares to HDMI ?

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It was a surprisingly difficult to find an usb-c to usb-c cable that is at the same time 3.1 Gen2 (for the video support) and two metres long. This Sandberg cable should do the trick and it actually might be able to charge the PPM too? Manufacturers website states that it supports power up to 65w (although the package says 61w). This PPM cable thing is cryptic…

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Hi @Arnaud the lag via USB-C should be similar to HDMI (around 36 ms).

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Thanks !

You can’t be wrong if you go for a Thunderbolt 3 cable from Apple, but it is 8 - 10 times more expensive than a basic HDMI cable. Other brands may be 25% - 50% of Apple price, but if you want to make sure the cable you buy could be used for anything you want, it might be more secure to go for the pricey one.

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