Access to text-mode screen captures... as text

Discussion about using the VirtualBox API, Tutorials, Samples.
Post Reply
bifferos
Posts: 19
Joined: 16. May 2008, 16:29

Access to text-mode screen captures... as text

Post by bifferos »

Using VBoxManage I can get a capture of the screen, but I want to do some OS install automation without the benefit of the guest additions (wait for a screen, press a key, etc...). I wondered if there's a trick to getting the text-mode text from the screen before VirtualBox renders it into the frame buffer so I don't have to do OCR on the captured images.

I'm prepared to recompile VB to get this information out, I wondered if anyone knows how difficult it would be?

Thanks!
mpack
Site Moderator
Posts: 39156
Joined: 4. Sep 2008, 17:09
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Mostly XP

Re: Access to text-mode screen captures... as text

Post by mpack »

The only place text is available is inside the app which generates it. VirtualBox has no knowledge of what pixels on a graphics display mean in the collective. And even if you're correct that you are using an actual text mode, and not graphics mode displaying a text font, it certainly isn't a stream: there is no requirement for the display to be updated in linear order.

So, no. I'm afraid not.
smailloux67
Posts: 1
Joined: 13. Oct 2021, 18:40

Re: Access to text-mode screen captures... as text

Post by smailloux67 »

Hi,

Also want to do OS install automation!

It would have been nice to have that feature. It would solve my issue of selecting the correct boot in a EFI GRUB.

Right now, it is a shot in the dark and if the boot order changes for any reason my program wont work.

May be I could compare picture or go through OCR process... A lengthier process for sure.
Or use real HW with a KVM
scottgus1
Site Moderator
Posts: 20965
Joined: 30. Dec 2009, 20:14
Primary OS: MS Windows 10
VBox Version: PUEL
Guest OSses: Windows, Linux

Re: Access to text-mode screen captures... as text

Post by scottgus1 »

Post Reply