View source for APNG

== APNG ==

APNG stands for Animated PNG, an extension to the PNG specification to allow for animated PNG images. Similar to how Animated GIF is an extension of GIF. Create such a thing.

== Project Leader(s) ==

[[User:Andrew|Andrew Smith]] (andrew on [[FAQ|IRC]])

== Project Contributors ==
Ben Hearsum - taught me to connect to the cluster using rdesktop, vmware and set up an account for me to compile mozilla on the windows cluster.

Mark Paruzel - made two fancy animations for demoing APNG, not up on the web yet.

Tom Aratyn - spent a few hours with me trying to solve an inheritance problem.

Jeff Mossop - [[IconsForAPNG|Created Icons for Andrew]]

== Project Details ==

The project is broken up into several stages:

1. ('''complete''') Create an [http://wiki.mozilla.org/APNG_Specification extension to the PNG Specification]. [http://pavlov.net/blog/ Stuart Parmenter] and [http://blog.vlad1.com/ Vladimir Vukićević] did this in around 2004.

2. ('''complete''') Implement the APNG spec into [http://www.libpng.org/pub/png/ libpng]. This was done for libpng 1.2.10 during the summer of 2006. [http://littlesvr.ca/apng/diff/libpng-1.2.10-apng.patch Patch] available on the [http://littlesvr.ca/apng/ APNG implementation page].

3. ('''current, fall 2006''') Implement the modified libpng into Mozilla.

4. Attempt to get the APNG patch integrated into libpng.

5. Fail.

6. Give up.

7. Try again.

== Project News ==
- compiled mozilla on slackware

- installed vmware and windows

- installed cygwin

- compiled mozilla on windows

- compiled mozilla on a mac

- attempted to fix a bug in libpng 1.2.12 that caused mozilla on a mac to crash, someone beat me to it

- tried to move things from imgContainerGIF to imgContainer and share that code using inheritance, didn't work

- rather than moving things, copied them instead. will do the inheritance thing later after it works

- made a webage for testing, with a gif, a png and an animated png

- updated the libpng patch to work with 1.2.12

- updated the apng spec and libpng patch with a small change requested by the libpng maintainer

- wondered why it still doesn't work

- spent a few days looking at the gif container to get a better idea of how it works

- fixed imgcontainer and pngdecoder to work with animations

- made some more images for testing

- made the gif decoder use imgcontainer

- removed imgcontainergif and replaced all references to it with imgcontainer

- finished patch, posted in bug 257197, waiting for review

== Links ==

[http://wiki.mozilla.org/APNG_Specification Extension to the PNG spec]

[http://www.w3.org/TR/PNG/ Original PNG Spec]

[http://littlesvr.ca/apng/ APNG Implementation Page]

[http://www.libpng.org/pub/png/ libpng page]

[https://bugzilla.mozilla.org/show_bug.cgi?id=257197 Bug 257197]

[https://bugzilla.mozilla.org/show_bug.cgi?id=257263 Bug 257263]

== End of Project ==

The libpng and mozilla patch are in one file on mozilla's bugzilla: [https://bugzilla.mozilla.org/attachment.cgi?id=245594]

Use a diff viewer to look at it, or the `patch` to apply it to the current (December 2006) Mozilla tree.

Sample images are available at [http://littlesvr.ca/apng/]