What is raspivid preview coordinate system?

[HermannSW]

I used below bash scripts to place unicode Full Block character U+2588 into bottom right of HDMI monitor console:
https://www.fileformat.info/info/unicod ... /index.htm

Then I tried to place raspivid 640x480 preview window into bottom right corner of the console (from ssh session).

For 1024x768 console this command is needed:

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raspivid -md 7 -w 640 -h 480 -p 976,552,640,480 -t 0

976+640=1616
552+480=1032

Fore 1366x768 console this command is needed:

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raspivid -md 7 -w 640 -h 480 -p 1196,552,640,480 -t 0

1196+640=1836
552+480=1032

Is there an explanation for 1616x1032 / 1836x1032 corrdinate system for raspivid preview on 1024x768 / 1366x768 console?

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[email protected]:~ $ cat 1024
#!/bin/bash
echo -n "0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456█"
while (true)
do
sleep 1
done
[email protected]:~ $ cat 1366
#!/bin/bash
echo -n "01234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789█"
while (true)
do
sleep 1
done
[email protected]:~ $ 

[6by9]

I'm very confused as to what you're trying to do/saying is wrong.

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tvservice -e "DMT 16 DVI"

to force 1024x768

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raspivid -md 7 -w 640 -h 480 -p 976,552,640,480 -t 0

gives me a preview image that is mainly off the screen, as shown with "vcgencmd dispmanx_list"

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[email protected]:~ $ vcgencmd dispmanx_list
display:2 format:YUV420 transform:0 layer:2 src:0,0,48,216 dst:976,552,48,216 cost:206 lbm:1024

visible region is 48x216 with the rest being cropped off.

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raspivid -md 1 -w 640 -h 480 -p 384,288,640,480 -t 0

gives me the complete preview window in the bottom right, as confirmed by vcgencmd again:

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[email protected]:~ $ vcgencmd dispmanx_list
display:2 format:YUV420 transform:0 layer:2 src:0,0,640,480 dst:384,288,640,480 cost:535 lbm:10240

Repeating with

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tvservice -e "DMT 81 DVI"

to force 1366x768.

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raspivid -md 7 -w 640 -h 480 -p 1196,552,640,480 -t 0

gives

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display:2 format:YUV420 transform:0 layer:2 src:0,0,170,216 dst:1196,552,170,216 cost:274 lbm:3072

for 170x216 visible.

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raspivid -md 7 -w 640 -h 480 -p 726,288,640,480 -t 0

gives me the full preview window

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display:2 format:YUV420 transform:0 layer:2 src:0,0,640,480 dst:726,288,640,480 cost:535 lbm:10240

[HermannSW]

Hi,

> I'm very confused as to what you're trying to do
>
I was trying to make sense of the preview coordinate system.

> /saying is wrong.
>
I did use "fbset" to change framebuffer resolutions and got what I reported.
This is posting explaing how I got the 1366x768 mode:
viewtopic.php?f=66&t=214053#p1317956

I did again with fbset commands and took photos of the HDMI monitor, with raspivid command from you:

The first two photos show what I reported above:

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[email protected]:~ $ fbset -fb /dev/fb0 1368x768-60
[email protected]:~ $ raspivid -md 1 -w 640 -h 480 -p 384,288,640,480 -t 0

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[email protected]:~ $ fbset -fb /dev/fb0 1024x768-60
[email protected]:~ $ raspivid -md 1 -w 640 -h 480 -p 384,288,640,480 -t 0

Then I tried with "tvservice" command you used, 1st gives correct result (right bottom preview in 1024 central part of monitor), 2nd shows "Format nicht unterstützt" which is German for "format not supported":

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[email protected]:~ $ tvservice -e "DMT 16 DVI"
Powering on HDMI with explicit settings (DMT mode 16)
[email protected]:~ $ unblank
[email protected]:~ $ raspivid -md 1 -w 640 -h 480 -p 384,288,640,480 -t 0

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[email protected]:~ $ tvservice -e "DMT 81 DVI"
Powering on HDMI with explicit settings (DMT mode 81)
[email protected]:~ $ 

So current summary is that 'tvservice -e "DMT 16 DVI"' works for 1024x768 console mode, and my monitor does not support DMT mode 81. And that changing console mode via fbset makes raspivid preview coordinate system become strange.

[6by9]

I'm not overly familiar with fbset, but almost certainly it is not changing the hdmi mode. It's only changing the resolution of an image buffer into which linux is rendering, and then the hardware will resize that for the selected hdmi mode.
Raspivid will always use the hdmi mode resolution.
To change the hdmi mode you need to be using tvservice. tvservice -s will always tell you the current mode.

The only reliable command for seeing what is actually being rendered including overlays is vcgencmd dispmanx_list.

[HermannSW]

Thank you for pointing me to HDMI mode, I only had to undo all I did sofar in this thread
viewtopic.php?f=66&t=214053&p=1318439#p1318439
and just add two lines forcing DMT hdmi_mode 39 to get 1360x768.

With that setup your command correctly places the preview window into bottom right corner:

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raspivid -md 7 -w 640 -h 480 -p 720,288,640,480 -t 0

720+640=1360
288+480=768

In order to verify I executed below script "1360", and used 719/287 instead of 720/288:

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raspivid -md 7 -w 640 -h 480 -p 719,287,640,480 -t 0

And really exactly one pixel row at bottom and 1 pixel column at right of full block character becomes visible:



This is the script used to verify:

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[email protected]:~ $ cat 1360
#!/bin/bash
echo -n "0123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678901234567890123456789012345678█"
while (true)
do
sleep 1
done
[email protected]:~ $