spumux bug causing error in dvdstyler

I have the same problem too
Debug output

DVDStyler v1.8.1
Linux 2.6.35-28-generic x86_64
FFmpeg: libavformat 52.64.2, libavcodec 52.72.2, libavutil 50.15.1
Prepare
Cleaning temporary directory
Search for transcoded files in cache
Generating menus
Generating menu 1 of 3
Prepare
Create menu mpeg
Multiplexing subtitles (buttons) into mpeg
Executing command: spumux -s 0 "/tmp/dvd-tmp/menu1-0.mpg_spumux.xml"
DVDAuthor::spumux, version 0.6.18.
Build options: gnugetopt imagemagick iconv freetype fribidi
Send bugs to <email address hidden>
INFO: Locale=en_CA.UTF-8
INFO: Converting filenames to UTF-8
STAT: 0:00:00.000
INFO: Picture /tmp/dvd-tmp/menu1-0.mpg_buttons.png had 1 colors
INFO: Picture /tmp/dvd-tmp/menu1-0.mpg_highlight.png had 2 colors
INFO: Picture /tmp/dvd-tmp/menu1-0.mpg_select.png had 2 colors
INFO: Pickbuttongroups, success with 1 groups, useimg=1
INFO: Found EOF in .sub file.
INFO: Max_sub_size=76
WARN: Button y coordinates are odd for button button02: 120x333-292x361; they may not display properly.
INFO: 1 subtitles added, 0 subtitles skipped, stream: 32, offset: 0.50
Statistics:
- Processed 0 subtitles.
- The longest display line had -1 characters.
- The maximum number of displayed lines was 0.
- The normal display height of the font arial.ttf was 0.
- The bottom display height of the font arial.ttf was 0.
- The biggest subtitle box had 76 bytes.
Generating menu 2 of 3
Prepare
Create menu mpeg
Multiplexing subtitles (buttons) into mpeg
Executing command: spumux -s 0 "/tmp/dvd-tmp/menu1-1.mpg_spumux.xml"
DVDAuthor::spumux, version 0.6.18.
Build options: gnugetopt imagemagick iconv freetype fribidi
Send bugs to <email address hidden>
INFO: Locale=en_CA.UTF-8
INFO: Converting filenames to UTF-8
STAT: 0:00:00.000
INFO: Picture /tmp/dvd-tmp/menu1-1.mpg_buttons.png had 4 colors
INFO: Picture /tmp/dvd-tmp/menu1-1.mpg_highlight.png had 5 colors
INFO: Picture /tmp/dvd-tmp/menu1-1.mpg_select.png had 5 colors
INFO: Pickbuttongroups, success with 2 groups, useimg=0
spumux: subgen-image.c:897: imgfix: Assertion `useimg' failed.
Failed

It seems that the problem involves the use of the useimg variable in the assert function. The assert function requires a boolean value but the useimg variable is clearly an integer which can at times be less than 0. The following change to the subgen-image.c file on line 900 (the error message states line 897 but it's line 900 in the version I'm using) will enable you to create the menus without any errors.

//assert(useimg);
assert((useimg > -1));

Unfortunately there are some serious issues with the buttons in the finalized menu even after making the change above. The menus are created without any errors but some of the buttons don't appear at all until you hover over them. Or the borders that surround some of the buttons may be missing or may be the wrong color.

You are probably trying to use too many colours at once. You are only allowed 4 per image.

Can you post or send me the PNG files you are trying to make into a menu?

I'm using one of the built-in menu templates in dvd styler. I haven't used any of my own images for the buttons. There is only one image button that I'm currently using but it is a svg arrow image included in the dvd styler software. I've rotated it 180 degrees and changed the color for highlighting and selecting. I initially had a few buttons that used the color red in their highlighting but I've removed that color and now use a total of 4 colors (white, gold, and 2 shades of blue) for borders, highlighting and selecting on all of the buttons.

After I removed the red color I no longer receive the spumux error and I'm able to use the original source code. Unfortunately after the dvd creation is completed the menus do not display the borders around the single-frame buttons or the arrow buttons until you hover over them. And even then some of the borders are either the wrong color or are multi-colored. I've included a few screenshots of this effect in the attached zip file.

The attached zip file contains examples of 2 of my menus as well as screenshots of the properties window for each button type. The "single-frame-button" image represents the grid of box shaped buttons that display a single frame from a video clip. I've also included the svg arrow image used in dvd styler.

Is this a dvdauthor/spumux bug or a dvdstyler bug?

OK, I’ve had a look at those samples. Is that dvdstyler-menu1.jpg a snapshot of the complete menu? Is that the background image, or the menu subpicture layer? Because it almost certainly won’t work as a subpicture—too many colours.

I see arrow.xml is an SVG file. SVG is likely to cause you problems if you don’t manage it properly, because the rendering libraries seem to insist on doing anti-aliasing, which will increase the number of colours in the image way beyond what you might expect.

(Just to clarify, I’m the current principal developer for dvdauthor. I”m not really familiar with dvdstyler or any of these other GUI front ends.)