PLAYPAL to RGB converter

The purpose of this tool is to convert raw PLAYPAL files into raw RGB files. These raw RGB files can then be converted into PNG files with tools like ImageMagick.

Compilation

make

Usage

The tool takes the path of a palette file as argument, reads the image in PLAYPAL format from stdin and writes out the image in RGB format to stdout. This output can be piped to the convert tool from ImageMagick to produce an output file in PNG format.

./playpal2rgb palette.raw < framebuffer.raw | convert -depth 8 -size 320x200 rgb:- framebuffer.png

Input format

The input to the playpal2rgb tool should be in PLAYPAL format, where each byte encodes the index of the color in the PLAYPAL table. The PLAYPAL table should be provided in a palette file, which also has a specific format.

Output format

The output of the playpal2rgb tool is in RGB format, where...

• R is 8 bits for the red component;
• G is 8 bits for the green component;
• B is 8 bits for the blue component.

... and it has the following memory layout.

+------------+-----+-------+-------+
| byte index | 3*n | 3*n+1 | 3*n+2 |
+------------+-----+-------+-------+
| data       | R   | G     | B     |
+------------+-----+-------+-------+

Palette format

The palette is assumed to be written in RBGX format, where...

• R is 8 bits for the red component;
• G is 8 bits for the green component;
• B is 8 bits for the blue component;
• X is 8 bits for padding (unused).

The palette should be written to a binary file of 1024 bytes with the following memory layout.

+------------+-----+-------+-------+-------+
| byte index | 4*n | 4*n+1 | 4*n+2 | 4*n+3 |
+------------+-----+-------+-------+-------+
| data       | R   | G     | B     | X     |
+------------+-----+-------+-------+-------+