https://github.com/unixpickle/GifPro

My new and improved Gif encoder for Mac
https://github.com/unixpickle/GifPro

Last synced: 2 months ago
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My new and improved Gif encoder for Mac

• Host: GitHub
• URL: https://github.com/unixpickle/GifPro
• Owner: unixpickle
• Created: 2011-11-04T02:35:19.000Z (about 13 years ago)
• Default Branch: master
• Last Pushed: 2011-11-20T22:08:37.000Z (about 13 years ago)
• Last Synced: 2024-04-14T01:11:45.456Z (9 months ago)
• Language: Objective-C
• Homepage:
• Size: 262 KB
• Stars: 43
• Watchers: 3
• Forks: 8
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

• awesome-gif - GifPro - GIF encoder for Mac. (GUI / Swift)

README

        
The ANGif Library

=================

ANGif is a small class library that can be used to encode Graphics Interchange Format files using a simple interface. It could easily be ported to platforms other than Cocoa (e.g. UIKit/CocoaTouch). The `ANGifEncoder` class is the root of all GIF encoding, and can be used as follows:

    ANGifEncoder * encoder = [[ANGifEncoder alloc] initWithOutputFile:@"myFile.gif" size:CGSizeMake(100, 100) globalColorTable:nil];

	[encoder addApplicationExtension:[[ANGifNetscapeAppExtension alloc] init]];

	[encoder addImageFrame:anImageFrame];

	[encoder addImageFrame:anotherImageFrame];

	[encoder closeFile];

The `addImageFrame:` method takes an instance of `ANGifImageFrame`, a basic class for enclosing images. The class itself can be instantiated using the `initWithPixelSource:colorTable:delayTime:` method. As of November 4th, 2011, the best color table to use is `ANCutColorTable`.

The `ANGifImageFramePixelSource` protocol is essential to the functionality of ANGif. It is suggested that you make a class that wraps a native image class such as `NSBitmapImageRep`, and implements all of the required methods.

The GifPro Project

==================

The Xcode project included with this repository is GifPro, a Mac OS X demo of what ANGif is capable of. The project includes `ANNSImageGifPixelSource`, an `NSBitmapImageRep` wrapper that conforms to the `ANGifImageFramePixelSource` protocol. The `ANExportWindow` class includes most of the code that directly interfaces the ANGif library.

Contribute a Color Table

------------------------

The GIF format works in a way such that files may only have 256 colors per image. This being said, algorithms exist to accurately calculate the best possible choices of colors for the 256-entry color table. The ANGif library is easily extendable to accomedate any color table algorithm that may be designed in the future.

If you are looking to implement a color table for ANGif, it is suggested that you have a look at the code for the `ANColorTable` base class. If you are still uncertain of exactly what you need to do to implement a color table, maybe have a look at `ANCutColorTable`. This was the first color table to be implemented for ANGif, and therefore should be a role model for those that follow.