A CD+G parser
This documentation is probably best read alongside CD+G Revealed
The CD+G format is very closely tied to the details of how compact
discs store audio; it's intended to be stored in the subchannel
data alongside normal Red Book audio. For the purposes of
consuming this data from a
.cdg file using this library, all
that it is important to know is that the file is divided into
sectors of 96 bytes, each of which represents 1/75th of a second.
The CD+G display model is a 300x216-pixel indexed color framebuffer divided into 6x12-pixel tiles, with a 16-color palette. The outermost cell on each side (i.e., the top and bottom 12 rows and the left and right 6 columns) are drawn a solid "border color" rather than drawn from the framebuffer.
A 12-bit RGB color
Iterator over the blocks within a sector. This produces a stream
A streaming iterator over the sectors read in from a reader. The
interface is the same as
A 6x12 tile, to be blitted to the display
One drawing command
A scroll command
Decode a single subchannel command. The input block must be exactly 24 bytes long. If the command is invalid for any reason, return None. Otherwise, returns the command.