2560 x 1080 on Pi?

Hi

Should this work on a Pi (yet)?

I have got as far as the Pi putting out the resolution correctly,

by this in the config.txt

hdmi_pixel_freq_limit=300000000
hdmi_cvt=2560 1080 50 7 0 0 1
hdmi_group=2
hdmi_mode=87
hvs_priority=0×32ff

RISC OS displays in the centre of the screen.

I am using 4th June ROM.

When I try other modes it doesn’t scale correctly eg:

1. 2560 × 1080 (50.00Hz) 32bit (CVT)
   startmode
   mode_name: 2560 × 1080
   x_res:2560
   y_res:1080
   pixel_rate:188750
   h_timings:264,416,0,2560,0,152
   v_timings:10,21,0,1080,0,3
   sync_pol:3
   endmode

It is pillarboxed, and consequently fuzzy. The mouse however seems to think the screen is scaled differently (presumably correctly) because the location of the click doesn’t match the pointer.

The error isn’t limited to modes greater than 2K, some smaller modes overlap and are unusable

Thanks

I’m not sure if Raspberry Pi does support anything over 1920×1080.

It definitely does! Even the original Pi can do ultra-HD 3840×2160×24Hz.

The required settings have been posted on this forum, but I can’t find them at the moment :-(

My Pi. (Original – i.e. no mounting holes and 256MB) is outputting 2560×1080@50.

However, RISC OS is only putting out 1920×1080, and I have vertical borders.

The hardware is capable. It seems the version of RISC OS I am using is not. (It also loses settings on each reboot)

Even the original Pi can do ultra-HD 3840×2160×24Hz.

When you find them, do let me know! Complete with an idiot’s guide to installing everything necessary if you can… (I’ve currently got RISC OS 5.21 dated 08-Jul-13)

If I download the RC14 SD image from here: https://www.riscosopen.org/content/downloads/raspberry-pi do I have to do something with zero pain, or is that (a) already in there, or (b) not relevant to that image? And is that image up to doing 3840×2160@24Hz given a suitable MDF? I’ll put it on a different card and keep the one I’ve got that works (with the 1600×1200 monitor)… :)

The monitor (TV, but only used as a monitor) is a Philips 4900 series. The Mac’s driving it at 3840×216030Hz, but the documentation says it'll do 3840x216024Hz. It’s got two HDMI inputs, switchable from the remote, so not even any need to fiddle with the cables.

The RC14 image predates zero page relocation, so you don’t need to worry about ZeroPain.

Is that the one likely to work in full screen without a disappearing mouse?

I tried the very latest.

Support for mouse pointer in modes >2048 was added 9th? July 2015. RC14 I think pre-dates that. The overnight builds should have it.

:( yes, it does predate that: 23rd Feb 2015. I think I’ll stick with my 1600×1200 for a while.

I have now got 21 sept 2016 (5.23H) RISC OS and 24 Sept 2016 firmware.

Modes other than 1080p do not scale correctly, and the mouse doesn’t align.

1080p works correctly (with borders) except in 16M colours where Red and Blue are swapped. (except on the mouse pointer, when it is anywhere but the far right of the screen, presumably 2048 pixels on the GPU output).

Do I have the correct firmware versions and RISC OS versions?

Do I have the correct firmware versions and RISC OS versions?

Yes, but you need to edit the config.txt file – see https://www.riscosopen.org/forum/forums/11/topics/6440?page=2

If your monitor doesn’t do 3840×2160 then the corresponding lines in config.txt need editing to suit your monitor.

disable_overscan=1
hdmi_group=2
hdmi_drive=2
fake_vsync_isr=1
gpu_mem=64
init_emmc_clock=100000000
kernel=RISCOS.IMG
hdmi_mode=87
hdmi_cvt=2560 1080 50 7 0 0 1
max_framebuffer_width=2560
max_framebuffer_height=1080
hdmi_pixel_freq_limit=400000000

I wonder if there is an issue with 21:9 aspect ratio.

2560:1080 isn’t exactly 21:9, but I don’t think it matters: the GPU scales the image. I don’t know whether the GPU can run 50Hz on 2560×1080 – can your monitor not accept a slower frame rate? Also, is gpu_mem=64 enough? I’d have thought it was, but I don’t know.

But I think it probably indeed is your 64:27 aspect ratio that’s the problem: see https://www.raspberrypi.org/documentation/configuration/config-txt.md – where aspect ratio 7 isn’t listed, and there’s nothing wider than 16:9 listed. If you change these three lines to:

hdmi_cvt=2560 1440 50 3 0 0 1
max_framebuffer_width=2560
max_framebuffer_height=1440

it might work by scaling, but I suspect it’ll just shear the image all over the place. RISC OS and the GPU will do their bit to scale to that frame, but your monitor may well not be able to accept it.

where aspect ratio 7 isn’t listed

I found this on some forum, but 3 doesn’t work anyway.

A scaled image would be awful, worse than what I have now.