221698 - PNG graphics wider than 4096 pixels yield to error

Status: RESOLVED DUPLICATE of bug 113406

(Core Graveyard :: GFX: Mac, defect)

Description

[Andreas Wolf]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC; de-DE; rv:1.0.2) Gecko/20021120 Netscape/7.01
Build Identifier: User-Agent: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O;en-US; rv:1.0.1) Gecko/20030306 Camino/0.7

Sorry that I cannot deliver any more recent browser build results. The Mozilla
line for MacOS9 is broken with version 1.2.1, and the latest Gecko based browser
I can test is the 0.7 Camino build. So maybe this bug/limitation is an
anachronism...
Trying to load simple PNG images (i.e. 4 bit color table, no alpha channels, no
interlacing, no whatever), but extending beyond 4096 pixels in width (e.g.
4600x128) always results in an error message saying that the image contains
errors and cannot be displayed. This is the same on all Gecko browsers I could
get hands on (Netscape7 MacOS9, Camino0.7 OSX, Netscape7 NT4, Mozilla1.2.1
MacOS9). Sadly enough, MSIE Does display the images correctly, as do really old
versions of Netscape (4.x) and iCab (Mac only browser).
I put an example of a 6000x128 pixels PNG image on our web-page for testing. I
really would appreciate some feedback on this (even answers like "this issue has
been solved centuries ago, stupid". I could't really find a corresponding bug
report for this.
Thanks, Andreas

Reproducible: Always

Steps to Reproduce:
1.locally or remote loading of a corresponding image
2.
3.

Actual Results:  
error message (translated from German): The image "http://www.seqlab.de/6000.png
cannot be displayed because it contains errors"


Appears to be a general problem, since I can observe it on different platforms

Comment 1

[Matthias Versen [:Matti]]

wfm with win2k build 20031009

Comment 2

[tor]

wfm linux trunk

Comment 3

[tor]

mac gfx is throwing out images that have more than 16384 bytes in a row
(width 4096).

  http://lxr.mozilla.org/seamonkey/source/gfx/src/mac/nsImageMac.cpp#614

Comment 4

[Andreas Wolf]

Well, thanks for the pointer to the source. I might be wrong, but the limitation
of 16384 rowbytes for Mac/QuickDraw pixelmaps does not automatically mean that I
cannot exceed 4096 pixels. The images I was using have a 4 bit resolution and
thus should use half a byte per pixel, correct? That would allow for 32768 pixels. 

Where am I wrong?

Comment 5

[tor]

Internally mozilla deals with images at 3 bytes/pixel (four bytes/pixel on MacOS).
Platform gfx is allowed to downsample this as appropriate, and on unix most images
are stored at display depth and the fatter representation thrown away.

Comment 6

[Simon Fraser [no longer active]]

Dup of bug 113406

*** This bug has been marked as a duplicate of 113406 ***