There are too many bugs in your script

Try following:

1. Somebody created a groop and wrote posts there.

2. Join the groop and you won't be able to see its content, images etc

   I think, I help you to find bugs and even do not wish to tell me how exclude only .gif image from regenerating to jpeg

   I can tell you how to make URL in post as link to click if you need it

@Am, Zet is right, we are working on 2.0 version we can only tell you how to do that, but we can not help you to program that.

How you can upload gif?

Pictures are uploaded using OssnFile class take a look in /classes/OssnFile.php (OssnFile::addFile())

We will not provide you any fix if you loss your ossn settings while editing core files.

nobody asked you to 'teach' anyhting

Am,
my (of course private) position is: This forum is meant to exchange and discuss feature requests, good ideas and yes: to talk about problems. What this forum cannot provide is teaching HOW to program these ideas or how to fix those problems. There might be seldom cases when fixing means to change just one line or parameter, but most of the time it needs a lot more.
What are you expecting Arsalan to do? To tell us: Grab file X and change line 125, 238, 299 to ..., then grab file Y and remove line 33 and replace it with new code that reads ...
Doing it like that would cost Arsalan hours of valuable programming time. And as a result delay the release date of 2.0 to late summer. And I think, nobody of us really wants that. :)

I think, in this file /libraries/ossn.lib.image.php what should be change so that not conver to jpeg, to leave all the image types what they are ?

.gif is uploading but animation lost

Can you show me a way to enable animation ?

Can you point the files in github ?

I do not need the animated gif community ..

No need to. Uploading gifs is already working with Ossn 2.0-dev.

But there's still a drawback: Resizing. Resizing destroys animated gifs.

In other words: With the current implementation you'll never get the chance to build up a community of animated gif lovers :)

e.g. in google plus you can upload .gif

tell me the responsible for image file names I will make a try to change

That's an aspect you should think about twice. Many communities are based on sharing high quality pictures and they wouldn't want a program to change or shrink their work. Talking about disk space, it's much better to have flexible upload limit.