84080 - Animated GIFs w/transparency do not properly animate/overclip

Status: RESOLVED FIXED

(Core :: Graphics: ImageLib, defect)

Description

[Kelly Price]

Animated GIFs are overclipped durring animation -- the animation doesn't leave
the previous image, and overwrites with the background color.  It's broken in
respect to NS 4.77

To reproduce:  Pull up the above URL, and click on the razor image, the Canadian
image, or the muddy image.  It will pull up the animation to show it's full
effect.

Comment 1

[Chris Lyon]

I think this is a dupe of bug 77914.

Can someone confirm?

Comment 2

[Andreas M. "Clarence" Schneider]

Yes, they are affected by bug 77914, but not only transparent areas turn black.

Comment 3

[Boris Zbarsky [:bzbarsky]]

see also bug 77334

Comment 4

[Kelly Price]

I doubt it's related to bug 77914, but more towards bug 77334, since the
background is used in the overwrite.

Can't we just unoptimize each GIF animation, which would simplify animation and
fix clipping to the GIF image itself?  I haven't looked at the code, but I have
a feeling that whatever code handles the animations in GIF tries to do all the
animation in a complicated way (trying to do all the overlaying/etc) instead of
doing simple unoptimized page flipping in one layer with transparency.

Comment 5

[Tom Mraz]

*** This bug has been marked as a duplicate of 77334 ***

Comment 6

[Asko Tontti]

Did you meant the following images?

  harrycanuck.gif
  gittesharry.gif
  apocharrynow2.gif

This is not clipping problem in Mozilla but in these images and NS 4.77
seems to be broken.

For example harrycanuck.gif uses "restore to background color" as a dispose
method for frame 7 so Mozilla clears drawing area with the background color
before drawing frame 8 as instructed. Frame 8's visible area is narrower than
frame 7 so clipping in is in the orignal image file.

Thus this is not a dup of bug 77334 - reopening for fixing resolution.

Comment 7

[Asko Tontti]

Reporter, if you think I have misunderstood the problem, please reopen this bug.

Comment 8

[Kelly Price]

You did.  NS 4.7x and IE 5 correctly view the animations.<P>

This bug is reopened.  The web browzer shouldn't classify the "background" as
being the page unless it's the first frame of the GIF animation.  It should be
the merged previous frames.<P>

Comment 9

[Benjamin Mucci]

Take a look here:

http://www.geoscopie.com/managinter/images/globetrotter.gif

I don't know if it's the same bug... This animation is Ok in NS4.78

Comment 10

[Kelly Price]

It's the same bug, on that site.  Chalk up another datapoint.

Comment 11

[Mike Young]

Im inclined to believe this is a dup of bug 22607

Please speak up if you disagree.

Comment 12

[Kelly Price]

I'm not sure myself, it may be part of a larger case.  I'm going to pop in a
"depends on" for this bug at the very least.  I think fixing that may fix this.

Comment 13

[Keyser Sose]

Marking NEW.

Comment 14

[T.Terlemez]

Attachment: looking man

Comment 15

[Sean Young]

Another example:

http://www.msxnet.org/konami/SD-Snatcher/WalkSnatcher.gif

Comment 16

[Stephen Anderson]

Is this a dup of bug 46995?

Comment 17

[Mike Young]

Many of the Animated Gif Bugs are so confused and interrelated, that I feel the
only way to know for sure whether one is a dup of the other is to wait until one
is fixed. To verify a bug fixed, QA needs to go through all of the dups and
dependencies as well, so marking duplicates when bugs are this confused would
not really solve many problems. 

The best solution (if there is to be little or no progress in animated gifs
before 1.0) is to create new bugs with each of the animated gif problems
specifically. This would include (but not be limited to) Remove by nothing,
Clipping region, Background Chunk in Transparent first frame, remove by previous
and several others I am probably forgetting. 

As it stands now, I'd say wait until a developer makes a decision about the
status of these bugs before restructuring all 2500 of them. (That number may be
a bit low.) :-P

Comment 18

[gavin long]

*** Bug 112014 has been marked as a duplicate of this bug. ***

Comment 19

[Markus Hübner]

Another nice testcase
http://www.world-direct.com/mozilla/teams_files/teamshoping_explain.gif

Comment 20

[Koike Kazuhiko]

*** Bug 46995 has been marked as a duplicate of this bug. ***

Comment 21

[Martin Macok]

Visit http://www.cnts.cz/pressrel/ . There is an animated GIF image in the
center of the page (the only one), which is not animating. If you rightclick so
the popupmenu pop up over the image and then you turn popupmenu off (just click
somewhere else), the bitmap that was hidden under popupmenu switches to
different GIF frame. The image gets messed up.

If you load just the image http://www.cnts.cz/pressrel/baterka_tr.gif it is
animating. If you load the page http://www.cnts.cz/pressrel/ the image is not
animating.

(20020407 trunk, Mandrake Linux 8.2)

Comment 22

[Eugene Savitsky]

For the last testcase.

You can just press CTRL-A or CTRL-TAB + CTRL-TAB and you'll see different frames.

moz 2002040403, Win XP

Comment 23

[Alexey Chernyak]

*** Bug 125904 has been marked as a duplicate of this bug. ***

Comment 24

[ArronM (:paper)]

*** Bug 141401 has been marked as a duplicate of this bug. ***

Comment 25

[Michael Lippert]

This animated gif blanks out before it recycles. That doesn't happen on IE 5.5.
This sounds related to this bug so I'm adding this comment.
http://www.ezboard.com/intl/aenglish/images/emoticons/pimp.gif

Comment 26

[Michael Lippert]

oops, sorry forgot to mention the build and platform for that previous comment.
Win2k server sp2, and Mozilla 1.0 rc2 build ID:2002051006
Note that not all of the animated gifs on this page exhibit this blanking
behaviour, just a couple.
http://pub52.ezboard.com/bforsakenavengers19241.showEmoticonsHelp

Comment 27

[ArronM (:paper)]

*** Bug 144679 has been marked as a duplicate of this bug. ***

Comment 28

[ArronM (:paper)]

*** Bug 47543 has been marked as a duplicate of this bug. ***

Comment 29

[ArronM (:paper)]

*** Bug 149439 has been marked as a duplicate of this bug. ***

Comment 30

[ArronM (:paper)]

Whee!  This bug was fixed by Bug 85595
Build 2002061204, Win2k