[sciurius]

Okay, this is how far I've got.

The syntax for the {image} directive has a new argument 'id=XXX' that specifies a known asset identified by the id 'XXX'. 'XXX' may be an arbitrary identifier.
For the {image} directive, the asset should be an image.
How the relation from 'XXX' to the image is established is up to the application program.

One way to define an asset is with a special file comment (not to be mistaken with a ChordPro {comment}). Such a comment looks like:

Code:

##image: id=XXX

Minimal, or with all options:

Code:

##image: id=XXX src=im.png type=png width=1341 height=340 enc=base64

which is immedeately followed by the data for the image, base64 encoded, in lines that start with "# " (pound space).

Code:

# iVBORw0KGgoAAAANSUhEUgAABT0AAAFUCAIAAABp2w/aAAAABGdBTUEAALGPC/xhBQAAAER0RVh0
# U29mdHdhcmUAWFYgdmVyc2lvbiAzLjEwYS1qdW1ib0ZpeCtFbmggb2YgMjAwODEyMTYgKGludGVy
... many more ...
# AAd0SU1FB+AEBwgjAAJ9CYIAAAAedEVYdENvbW1lbnQAQ3JlYXRlZCB3aXRoIFRoZSBHSU1QCpgy
# LukAAAAASUVORK5CYII=

So when the user presents a ChordPro file with one or more {image}s, Companion can change the {image} directives and include the image data as shown above. For people that do not use Companion, there are other tools that can assist.

When a song is edited in MSPro, the asset data can be omitted to not clobber the view and/or slow down the editor.

What do you think?