All Questions
Tagged with framebuffer linux
154
questions
1
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1
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views
can we display same framebuffer side by side on screen simultaneously using DRM(direct rendering manager) APIs in linux?
can we display same framebuffer side by side on screen simultaneously using DRM(direct rendering manager) APIs in linux?
constraints:
need to use single plane and single framebuffer
what I already ...
0
votes
0
answers
58
views
Program using framebuffer killed on Ubuntu 18.04 but works on Ubuntu 22.04
I'm currently developing a program that interacts with the framebuffer. The program works perfectly on Ubuntu 22.04, but it gets killed with the message "killed" on Ubuntu 18.04.
Here is the ...
- 19
0
votes
1
answer
77
views
My embedded application doesn't receive keyboard events (Linux framebuffer/Qt+QML application/systemd service/VNC server)
I need to remotely control a Qt / QML application on an embedded ARM instrument. I intended to do that using VNC. This doesn't work. An USB keyboard plugged in the instrument doesn't work either.
NB: ...
0
votes
2
answers
69
views
Error hit when show a cropped JPEG on LCD (ARGB) display
I am trying to crop a big JPEG photo and show it into LCD display in my Linux.
I am using libjpeg to decode the photo, and convert the RGB to ARGB to show the cropped part onto the LCD.
But the ...
- 1,069
0
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0
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251
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Linux tcgetattr followed by tcsetattr not working
I need to save the terminal attributes (tcgetattr), set them to something that will block terminal echoing etc. (calling tcsetattr), and then later, after doing things with the framebuffer device /dev/...
- 33
2
votes
1
answer
64
views
Failed to show JPEG on LCD (black) with RGB888 using libjpeg in Embedded Linux
I am working on an embedded Linux system (kernel-5.10.24), there is a LCD display in it.
Now I am trying to show a JPEG picture on the LCD by using libjpeg.
I found an example code on the internet and ...
- 1,069
1
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0
answers
218
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Can't read frame buffer colormap information using ioctl on raspberry pi
I am working on Raspberry Pi 4, with raspios bullseye-arm-64-lite (version 11).
I want to configure the frame buffer to 8-bits per pixel and use a custom colormap.
I configured the frame buffer to 8-...
- 11
4
votes
0
answers
687
views
Continously capturing/reading all frames from Xvfb virtual framebuffer as a stream?
I have a Linux system (Raspberry Pi 4 with DietPi) which controls some RGB LED Matrix panels, by transmitting buffers of RGB pixels.
I want to display the content of a virtual frame buffer on the LED ...
- 2,939
0
votes
0
answers
104
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How can I process pixels on screen if they don't mirror in /dev/fb0
I am currently working on a Raspberry Pi 4 with retropie and want to process the colours on the screen to do some cool stuff with LEDs. My Idea was to check the Linux framebuffer (/dev/fb0). It works ...
- 1
1
vote
0
answers
434
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Linux framebuffer not updating when using KD_GRAPHICS
I've been trying to do some old-school drawing on the Linux framebuffer. I'm aware this is not the "modern" way to do things but exploring it out of curiosity. I am confused that my screen ...
- 56
0
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0
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977
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Why doesn't writing to /dev/fb0 work on some video cards
I have a simple embedded Linux build that boots from a USB and has a framebuffer. There are simple bash scripts that write to the /dev/fb0 device to give user feedback and clear the screen, along ...
- 248
-1
votes
1
answer
239
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`fbcon/cursor_blink` permissions reset at reboot [closed]
Context
I need to stop the cursor from blinking on an external screen of my raspberry-pi in order to display a home-made interface on /dev/fb0.
For this purpose I created a group cursor_blink in which ...
- 1,144
1
vote
0
answers
203
views
Which frame ? - Linux framebuffer alternate
I read the Linux framebuffer dev/fb0 with mmap().
But it is an alternative framebuffer, so I get two images.
In one hand : char * map0 = (char *) mmap(nullptr, width*height*4, PROT_READ, MAP_SHARED, ...
- 11
1
vote
0
answers
87
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DRM mode_set not called for second DSI panel
I have two DSI bridges connected to my android module that has 2 DSI ports. Each panel works well if I do not set two panels in the device tree. But, when both displays are declared, only the primary ...
0
votes
2
answers
607
views
FBGrab gives a black .png image
I am using fbgrab to take a screenshot of my framebuffer. When I run fbdev as sudo fbdev capture.png it saves the file but when I open the image it is just a fully black image. I have also tried ...
- 185