FLAT_COMPRESSED Container Format

FLAT_COMPRESSED Container Format

Status: ✅ Cracked (container) — byte-for-byte verified.

The compression container used by eeuz.rt, .rl, .prl, .prd, .cl, .ct, .pct, .pca (files.cfg compressionType 1). This page covers just the container shell; see each file's own page for what's inside.

Layout

offset 0  : 3 bytes ASCII "zip"
offset 3  : 1 byte version (always 1 observed)
offset 4  : uint32 LE block_size            (3072 in every file checked)
offset 8  : uint32 LE total_uncompressed_size
offset 12 : uint32 LE val3                  (meaning unconfirmed/reserved)
offset 16 : offset table, uint32 LE x (ceil(total_size/block_size)+1),
            offs[i]..offs[i+1] delimits block i's compressed bytes

Each block is an independent standard zlib stream decompressing to exactly block_size bytes (the remainder, for the last block). Concatenating all decompressed blocks in order reproduces the exact original logical file.

Validation

Verified on eeuz.pca (decompresses to a clean phoneme/name catalog: "EUROPE", "AUSTRIA", ...) and confirmed at scale on eeuz.rt (62MB compressed).

Reader code

research/flat_compressed_reader.py.