Blizzard MPQ

byte {3}     - Header (MPQ)

byte {1}     - Header/shunt indicator (1A = Header, 1B = Shunt)

if (shunt) {

uint32 {4}   - Unknown

uint32 {4}   - Offset to header (relative to the beginning of the shunt)

}

else if (header) {

uint32 {4}   - Header length

uint32 {4}   - Archive length (Deprecated in World of Warcraft: The Burning Crusade)

uint16 {2}   - Version (0 = Original, 1 = Extended (World of Warcraft: The Burning Crusade and newer)

uint16 {2}   - Block size (Actual block size is calculated with 512 * 2^blockSize; because of bugs in the Storm library, this should always be 3 (giving a size of 4096 bytes))

uint32 {4}   - Offset to hash table

uint32 {4}   - Offset to block table

uint32 {4}   - Number of hash table entries (Must be a power of 2, and must be < 2¹⁶ for the original format, or < 2²⁰ for World of Warcraft: The Burning Crusade and later)

uint32 {4}   - Number of block table entries

if (formatVersion = 1) {

uint64 {8}   - Offset to extended block table

uint16 {2}   - High 16 bits of hash table offset for large archives

uint16 {2}   - High 16 bits of block table offset for large archives

}

}

// Hash Table (always encrypted)

// for each file

uint32 {4}   - File path hash (Hash method A)

uint32 {4}   - File path hash (Hash method B)

uint16 {2}   - File locale (Windows LANGID data type; 0 = American English or language-neutral; see also file locale table in Notes and Comments)

uint16 {2}   - File platform (0 = Default; always 0?)

uint32 {4}   - Block table index (If hash table entry is not valid, FFFFFFFF = hash entry is and always was empty (file never existed, file search ends), FFFFFFFE = hash entry is but not always was empty (file was deleted, file search continues))

// Block Table (always encrypted)

// for each file

uint32 {4}   - File offset

uint32 {4}   - Compressed file size

uint32 {4}   - Uncompressed file size

uint32 {4}   - Flags (See also block table flags in Notes and Comments)

// Extended block table (always unencrypted, only if formatVersion = 1)

for each file

uint16 {2}   - High 16 bits of file offset

// File data

// Block Offset Table (blockNumber + 1)

// for each block

uint32 {4}   - Block offset (Final entry stores size of last block)

// for each block

byte {x}     - File data (If data is uncompressed, size is indicated by 512 * 2^blockSize (normally 4096 bytes), if data is compressed, size is variable)