SGA

• Extension: SGA
• Samples: http://samples.mplayerhq.hu/game-formats/segacd/sga/

SGA is a rather common file format for games on the Sega CD console system. Little is known about the file format. It is likely to be some sort of vector quantizer due to the limited graphics capability of the Sega CD system.

File Format

All multi-byte numbers in a SGA file are big endian.

A SGA file is a headerless format that is comprised of a series of chunks. Each chunk can contain video or audio. The chunk layout is defined as:

byte 0     chunk type
byte 1     unknown
bytes 2-3  payload length
bytes 4-5  unknown
bytes 6..  chunk payload

Bytes 4-5 are presumed to be part of the chunk preamble since the payload length specifies the length of the chunk, minus 6 bytes.

Chunk Types

Some observed chunk types are:

• 0xCD: video, perhaps followed by audio
• 0xCB: video, perhaps in files that are video only
• 0xA1: audio, sign/magnitude 8-bit PCM, apparently with a few header bytes in advance

Games Using SGA

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