==V2D Format Specification==

The V2D disk image format stores nibble streams in a manner similar to the NIB format, but with these improvements:

* Supports quarter tracks
* Allows for a variable number of nibbles per track
* Stores only used tracks

16 and 32 bit integers are stored in big-endian byte order:

struct v2dHeader {
	unsigned int containerByteNum;	// filesize - 8
	char id[4];	// "D5NI"
	unsigned short trackNum;
}

For every track:

struct v2dTrack {
	unsigned short quarterTrackIndex;
	unsigned short trackByteNum;
}
