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 Post subject: Is GIF image support present?
PostPosted: Fri Sep 27, 2013 8:07 pm 
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Joined: Thu Mar 17, 2011 7:07 pm
Posts: 6
Last time I tested and read VisOpSys features I didn't find GIF support, and I remember to have seen that it wasn't implemented.

If so, why isn't GIF support implemented? The LZW patent is supposed to be expired also.

I have been able to implement basic GIF decompression in HTML5 (for the latest Firefox, Chrome and maybe Opera), and I know how to handle global and local palettes, and I know how to handle the different dispose methods for "animated" GIFs. Admittedly it is much easier than implementing it in C and in a kernel, but it is also easier to understand.

Here is the JavaScript code and the application. It contains errors that prevent a few GIFs to be shown, and probably it would be necessary to explain better how it works.

If GIF support isn't present for VisOpSys, maybe this could be useful. The whole source code and application are in the Public Domain, or Creative Commons 0 (CC0), which is equivalent:

Image GIF_Explainer_v2013-07-25-22-24.zip
Image


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 Post subject: Re: Is GIF image support present?
PostPosted: Sat Sep 28, 2013 9:10 am 
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Joined: Tue Nov 16, 2010 7:20 pm
Posts: 463
Hi ~, nice to see you again 8-)

Visopsys doesn't have GIF support yet, but only for the reason that nobody's gotten around to it, yet. There's BMP and JPG.

I don't know Javascript, personally, but it looks like something that wouldn't be too difficult to translate into C.

This is very helpful, thank you. I'm certainly interested in learning about this, but I do have quite a few important things that I'm trying to tackle, in addition to general maintenance, bug fixing, etc. For example I'm just finishing up a driver for AHCI disk controllers, and there's an XHCI USB3 controller driver that needs some testing and polishing before I can release it. Mostly, modernizing the hardware support. Also: networking.

All of which is to say that GIF support might need to wait a little while, unless someone else here would like to tackle this! This hypothetical person could port your GIF code into C, placing it into the image-processing framework in the same way that BMP (kernelImageBmp.*) and JPG (kernelImageJpg.*) are done.

Challenge extended! :lol:


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