HOW TO CREATE A MENU USING THE GIMP

1. for 4:3 NTSC, create a 720x480 image with 81x72dpi
   for 4:3 PAL, create a 720x576 image with 75x80dpi
   for 16:9 NTSC, create a 720x480 image with 81x96dpi
   for 16:9 PAL, create a 720x576 image with 45x64dpi

2. right click, select Image->Alpha->Add Alpha Channel

3. right click, select Layers->Layers, Channels & Paths
   create a layer called 'buttonmask', transparent

4. select the Background layer
   draw the menu background

5. select the buttonmask layer
   draw the button outline

6. save as a gimp image for future manipulation

7. hide the buttonmask layer.  save as image.jpg

8. show the buttonmask layer, hide the Background layer.  save as imagemask.png

9. create a image.sub file with
   <subpictures><stream>
   <spu start="0" image="imagemask.png" autooutline="infer" />
   </stream></subpictures>

10. run:
   jpeg2yuv -n 1 -I t -L 1 -f 29.97 -j image.jpg | mpeg2enc -f 8 -o image.m2v
   mplex -f 8 -o /dev/stdout image.m2v | spumux image.sub > image.mpg

color specification is as follows: there are up to 3 colors for a
particular menu.  When the button is not selected, they map to 1-3.
When the button is highlighted, they map to 4-6.  When the button is
selected, they temporarily map to 7-9.  You can create a palette file
that has 16 entries.  The colors need to be specified in YVU format.
A sample file would be:

    008080
    f08080
    008080
    008080

    51f05a
    902235
    286df0
    ca4892

    aaaea4
    de8948
    aeb76d
    49a6dc

    616389
    98bc51
    37b389
    718947

In that case 'f08080' is color#1, and 'de8948' is color#9.

