There are severe copyright issues surrounding GIF. PNG, on the other hand, it comparable in everyway, and is totally patent-free. It's also supported by Cocoa's NSImage, so making the change should not be too difficult.

Owen, to my knowledge, Chimera doesn't include a throbber. What Chimera build are you using that has one?

Chimera does include a throbber, but it is not enabled by default. Try customizing the toolbar to see it. It has been present in builds since June 15th I believe. One can also view such under-the-skin changes through the Bonsai CVS Log web interface (http://tinderbox.mozilla.org/ showbuilds.cgi?tree=Chimera&hours=5&nocrap=1 and click on bonsai query).

See also bug 8415.

The multiframe MNG format would be more appropriate than a string of PNGs.

The problem is the MNG is not a natively supported OS X format. PNG is. PNG can be loaded directly through the NSImage functionality, while MNG would require writing glue code to connect the NIXish MNG rendering to the OS X UI.

Should this include the dozens of other TIFFs and GIFs in Contents/Resources and Contents/MacOS/res?

TIFFs are not a problem. It might be advisable to change them all just for cosistency, but it's not necessary. I don't know what the graphics are in the res folder. If they're loaded through Cocoa's NSImage function, they can be switched around within a large number of formats with little or not effort. GIFs are the real problems, as CompuServe is very protective of their copyright on the GIF compression scheme.

I think whether we want to be consistent in image formats is ultra-trivial, but one nice thing would be that it would save maybe 1000KB, since gif and png can be optimized much more than tiffs. For example. Each of the toolbar icons, which are tiffs, are about 20k, whereas the first throbber frame, which is the same size but in gif, is 4k. The things that are in res are the image loadin and broken image icons (which will proabaly be replaced with aqua/chimera style ones anyway), and a little down triange (for toolbar menus?).

Oops, I meant could save 100K not 1000K

ffff

This seems simple enough. Jasper, is this something you can handle?

We are talking about the animated throbber, which currently is an animated GIF, which is very efficient in itself (and being further improved), mostly because it is threated by Gecko as one image object. A series of PNG's would be bad, because each frame will then be a separate image object (impacting the image cache). An alternative would be APNG, but the jury is not out on whether it is a 'standard' that Mozilla wants to take on. There is bug on APNG implementation: bug 257197, and one on the 'standard' issue: bug 257197. Having a animated 8bitalphatransparent animated throbber (instead single bit transparancy) would be nice, but let's postpone that to the above APNG issue has been resolved...

Alright, I'm adding bug 257197 as a dependency and we'll re-evaluate if/when it gets landed into the trunk.

Actually, checking the current resources, the throbber *isn't* an animated GIF. There are no fewer than 12 throbber files (throbber-01 through throbber-12, ironically enough). The weird thing is that the first throbber file (throbber-01) is a PNG while the rest are GIFs. So, again, I ask, how hard is it to change all the GIFs to PNGs and resolve this bug?

If it does not make pages tear like in tabs maybe it could use a real progress spinner and also fix bug 162353.

Our throbber is now a bunch of TIFFs, which handles licensing issues, I believe. My inclination is to WONTFIX this. Using an animated throbber has no advantages to what we currently have. In addition, since we use a Cocoa interface, wouldn't the OS have to support APNG? That seems far from likely. I suggest WONTFIX.

Marking WONTFIX per Sam's comment. This would just take to much work for such an "unimprtant" feature. We now use full traspararnt tiff, so we have smooth edges and stuff.

v.

The "severe copyright issues" mentioned in the original post were actually "patent issues", and they are no longer "severe". There is still a patent held by IBM on LZW compression, but it's about to expire and IBM has not used it against anyone other than SCO. The Unisys patents expired last year. So all that's really left are technical reasons for choosing a format.