Custom Resolution LED-Wall

Help
1

Hello,

I need a little help to get two, three things right together.

Information:

Custom Led Wall:
2688 x 384
----------+ ----------±---------±---------±---------±---------±---------±---------±---------±---------+
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
----------±---------±---------±---------±---------±---------±---------±---------±---------±---------+

Controller:
Novastar (capable of main + 2 PIP´s and three Imputs, each input (HDMI/DVI) max 1920x1080)

I need to separate the wall to play native on it, possible solutions:

Opt #1
---------------1344x384 ----------------------------- | ------------------- 1344x384
----------+ ----------±---------±---------±---------±---------±---------±---------±---------±---------+
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx|
----------±---------±---------±---------±---------±---------±---------±---------±---------±---------+

Opt #2
----------------- 864 x 384 ---------- 864 x 384 ---------------- 864 x 384
----------+ ----------±---------±---------±---------±---------±---------±---------±---------±---------+
|xxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxxxxx|
|xxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxxxxx|
|xxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxx|xxxxxxxxxxxxxxxxxxxxxxxxxxx|
----------±---------±---------±---------±---------±---------±---------±---------±---------±---------+

So i need to configure the PI under

„Configuration“
x – Set fixed video mode / dual screen configuration
|
→ Advanced/Development
|
→ Custom Pi boot

Opt #1

#hdmi_drive=2
#disable_overscan=1
hdmi_group:0=2
hdmi_aspect= ??
hdmi_cvt:0=1344 384 60 ? 0 0
hdmi_mode:0=87
hdmi_group:1=2
hdmi_cvt:1=1344 384 60 ? 0 0
hdmi_mode:1=87

Opt #2 ( two Pi 4)

FIRST PI dual Monitor Setting

#hdmi_drive=2
#disable_overscan=1
hdmi_group:0=2
hdmi_aspect=??
hdmi_cvt:0=864 384 60 ? 0 0
hdmi_mode:0=87
hdmi_group:1=2
hdmi_cvt:1=864 384 60 ? 0 0
hdmi_mode:1=87

Second PI (or 3 seperate Pi 4)

#hdmi_drive=2
#disable_overscan=1
hdmi_group:0=2
hdmi_aspect=?
hdmi_cvt:0=864 384 60 ? 0 0
hdmi_mode:0=87

my problem of understanding is the ascpect Ratio, nativ:

2688x384 = 7 : 1 ?
1344x384 = 7 : 2 ?
864x384 = 9 : 4 ?

should i leave hdmi_aspect empty in the config and which is the best possible Playback source, Nativ or upscaling from XXX x YYY resolution ?

Thanks

2

Thanks for the detailed problem description. :+1:

I don’t think you would need to specify the aspect ratio. In fact I’m not sure why the hdmi_aspect option even exists. The documentation doesn’t mention it and I cannot find any reference in the Pi firmware files either. For the hdmi_cvt option, only the first three values are required, so I would suggest you only keep width/height/framerate and omit the rest.

I’ve wondered about this in the past: I’m not even sure why the aspect ratio value exists. Maybe it’s a way for a screen to inform the OS in case it doesn’t have square pixels? Even then, there isn’t really anything info-beamer would do with that information as it just plays the content you assign the the available screen space. So it seems a pretty useless option.

Option 2 seems most promising, but a small caveat: The Pi4 (to my knowledge), has no way to force frame locked output across its two HDMI outputs. So there will likely be a small delay between sending output to its HDMI0 and HDMI1 connectors. I’m not sure how your controller handles this, but you might notice a tear across the middle of the output if that happens.

I’m not sure I understand. Is that an option for the controller? If the LED has a resolution of 2688x384 and you feed in two 1344x384 sources, I guess native seems appropriate as there is no need to scale the input to the available output as they perfectly match already?

3

thanks for the quick reply
I think i will give the solution with 3 pi´s a try

with the config:

#hdmi_drive=2
#disable_overscan=1
hdmi_group:0=2
hdmi_cvt:0=864 384 60
hdmi_mode:0=87

Which is the best solution to sync the 3 pi´s to get the Content like it is one big screen ?

Magic Video Wall - Video Wall Image/Video Player

Cut the Video in 3 pieces and merge it together to one video or is it possible to get the video played @ 2688x384 nativ on the 3 pi´s ?

4

Try using the default HD Image/Video Player first and activate its sync playback option. Create three setups, each with the playlist for one of the three cuts of each video. Make sure all playlists have the exact same duration. Then assign each to one device.

In theory H265 could do that, but it isn’t 100% reliable, so if you have the option to pre-process your videos, I suggest you do that and use three H264 videos instead.

5

Or use this Row Player thats somehow not visible in the solutions store