Due to the different versions that exist of the HDMI standard, this is prone to cause confusion, and for people to purchase a switcher that won't work properly with their PS4 Pro. So here is a guide that describes in detail what to look for.
Terminology and HDMI versions
An HDMI switcher is a device that has two or more HDMI inputs and one HDMI output, and is capable of redirecting one of those inputs to the output. This allows several HDMI sources (such as game consoles, a digital TV box, and a PC) to be connected to one single display.
An HDMI splitter is a device that has one HDMI input and two or more HDMI outputs. It allows for the image of a single HDMI source device to be redirected to several displays (possibly simultaneously).
Some devices are both, having multiple inputs and outputs. This is often denoted as (although the notation is not standardized) for example "3x1" for switchers (3 inputs, one output), "1x3" for splitters (one input, three outputs), and eg. "6x2" for devices supporting both (6 inputs, 2 outputs). Usually the latter allows for any two of the inputs to be redirected to the two outputs simultaneously. (Note that in some cases the "3x1" form may also be used for splitters. The notation is not always consistent.) Other devices are bi-directional, which means that they can be used as a switcher or a splitter (but not both at the same time, since they have only one port that functions as an input or an output, the others functioning as the opposite).
HDMI 1.3 and older only supports Full-HD resolutions, in other words, 1920x1080 pixels. It's completely unusable for 4k material.
HDMI 1.4 supports Full-HD video at 120 Hz, as well as 4k video (3840x2160) at 30 Hz. It has a bandwidth of 10.2 Gbps.
HDMI 2.0 supports 4k video at 60 Hz. It has a bandwidth of 18 Gbps.
Note that the PS4 Pro supports displaying 4k video at 60 Hz over an HDMI 1.4 connection, but only in YUV420 mode rather than RGB mode (if the display supports this). However, as far as I understand, this is a non-standard extension. YUV420 compromises image quality by reducing color information (in order to be able for the image to be transmitted at 10.2 Gbps.) RGB mode has no such compromise.
What to look for when purchasing an HDMI switcher/splitter
As of writing this post, switchers and splitters having full HDMI 2.0 support are still a rarity, and a user may be fooled into buying a device with no such support, only to find out that the PS4 Pro has switched to YUV420 mode or, in the worst case scenario, can't display an image at all (which is sadly common). Thus a potential buyer needs to be very careful when purchasing such a device.
Important note: Even if a switcher/splitter mentions "HDMI 2.0" support, this is not a guarantee that it will work properly with the PS4 Pro!
There are some such devices out there that mention such support, but still internally have a bandwidth of 10.2 Gbps (ie. the one from HDMI 1.4). If you try to use this kind of switcher/splitter with the PS4 Pro, you'll probably find out that the console will be limited to YUV420 mode (or, possibly, not being able to display anything at all)! I do not know how these manufacturers can make the claim of HDMI 2.0 support for these devices, but I'm assuming they support everything else in the standard except for the 18 Gbps bandwidth.
It's more important to look in the specifications of the device for a mention of support for 4k resolutions at 60 Hz. This may be expressed for example as "3840x2160@60Hz", or sometimes as "4Kx2K@60Hz".
If the specs for the device say "3820x2160@30Hz", or "4Kx2K@30Hz", or explicitly "HDMI 1.4" (often "HDMI 1.4b"), then it does not have HDMI 2.0 support. Avoid these.
Be wary of switchers/splitters that do not mention at all a refresh rate for the 4k resolution, nor a HDMI version. A mention of "4k" alone is not enough, and lacking the refresh rate is an almost sure sign that it's an HDMI 1.4 device.
Also, as mentioned, be careful with devices that do mention "HDMI 2.0" but not a refresh rate for the 4k resolution. These might or might not support the necessary bandwidth of 18 Gbps.
"How do I know if the PS4 Pro is using RGB or YUV420 mode?"
The PS4 system might not always make it completely clear which mode is being currently used, and whether 2160p RGB is supported. However, if you go to the system settings, choose "display and sound", and from there "video output settings" and "resolution", the "2160p - RGB (Unsupported)" line will be grayed out if using HDMI 1.4.
No comments:
Post a Comment