222340 - very slow rendering of a page with many png images with alpha channels

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Patrick Ruckstuhl]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5) Gecko/20031007 Firebird/0.7
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.5) Gecko/20031007 Firebird/0.7

The page renders extremely slow (eg. if minimze firebird and then maximize it
again or if a change to another tab and back). The effect is a lot bigger if I
have more png images on the page. In the old firebird 6.1. The page gets
displayed  instantaneously.

Reproducible: Always

Steps to Reproduce:
1. Browse to the page
2. Change to another task/tab
3. Change back to firebird/the tab displaying the page

Actual Results:  
Takes some time to show the page

Expected Results:  
show it instantaneously like in the old firebird 6.1

The example.html page was changed, in order to comply to the w3c standarts.
There is also another example with much more graphics. This page doesn't totally
strictly follow the w3c guidelines, but worked perfectly in firebird 6.1. It may
help show the extrem difference in the rendering speed.

Comment 1

[Patrick Ruckstuhl]

sorry, forgot to add the link to the second example:

http://www.wogen-des-schicksals.de/home/butcher/example-big.html

Comment 2

[Casey Weston]

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6b) Gecko/20031216
Firebird/0.7+

The page does load extremely slowly, but does anyone else have a 0.6.1 build to
test to confirm that it renders the page much faster?

Comment 3

[Patrick Ruckstuhl]

Some collegues of mine tried it also with the same results.

Comment 4

[firemotion+mozilla]

Tested this bug with:

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6b) Gecko/20031208
and
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6b) Gecko/20031216
Firebird/0.7+

I don't notice any difference in speed between the two. I expected it to be
"slower" than normal, but that can be expected with 114 images, total 448kb,
with alpha. (example-big.html).

If this *is* a bug, then I don't think it's limited to FireBird. Set to Browser
/ ImageLib?

Comment 5

[Vidar Haarr (not reading bugmail)]

WFM on WinXP trunk 2003120608.

Reporter: please try this again using a recent nightly build from
<http://ftp.mozilla.org/pub/mozilla.org/mozilla/nightly/latest/>. If it works,
please resolve this bug as WFM. Thanks!

Comment 6

[Christophe Jacquet]

Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.6b) Gecko/20031217 Firebird/0.7+

The rendering under Linux is not *very* fast, but it is not very slow either.

Using the same build of Firebird, loading under Linux on a Celeron-533 is *much*
faster than under WinXP on a P4-2.4 !

Confirming under WindowsXP.
Linux seems not to be affected by this bug.

Comment 7

[Wolf [:wolf]]

The page is rendered very slowly.. This needs to be moved to Browser and not
firebird... and to the correct component.. either layout or imagelib

Confirming for Windows XP
on 
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6b) Gecko/20031217 and 
Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.6b) Gecko/20031216
Firebird/0.7+

I'm not sure this qualifies as a bug, and isn't just a fact of such a complex
page. but I feel that the issue needs to be investigated further.. and not just
written off as that's the way it's supposed to be.

Comment 8

[Rob Hudson]

i tried 0.6.1 and it is still 'slow'. So it has nothing to do with the version
of FB used. 

Comment 9

[Vlad Dascalu]

Moving to Browser -> Layout, probably it could go better to imagelib due to the
alpha channel thing in the summary, but it needs further investigation.

Comment 10

[Patrick Ruckstuhl]

>WFM on WinXP trunk 2003120608.

>Reporter: please try this again using a recent nightly build from
><http://ftp.mozilla.org/pub/mozilla.org/mozilla/nightly/latest/>. If it works,
>please resolve this bug as WFM. Thanks!

jep, that was it with that version it works very fast again.