JCV File format

A junction view is a SVG file composed of multiple layers which may, or may not, be displayed. Layers have a type and ID.

There are 3 types of layers: signs, arrows, and backgrounds. A layer id is a number unique to layers of the same type in the SVG.

Most bytes of header &h61 are understood.

Pictures are in jpg , png or svg format and encrypted - see 0x37

The height and width of pictures follow the header.

Header Length
2
GARMIN JCV

version?
2
year
1
month
1
day
1
hour
1
minute
1
second
1
ID

Pointer to JCV1 containing ids
4
Length of record
2
length of block
4
Pointer to JCV 2
4
Length of block
4
encryption bytes to decode picture blocks
4
Pointer to JCV3
4
Length of block
4
Pointer to JCV4
4
Length of block
4

2

2
Pointer to JCV4
4
Length of block
4
?

base value for 0x64 - bytes for width & hight
2
multiples of 0x62 denoting number of picture sizes to follow
2
?

width of pictures
4
height of pictures
4