Asobo Save Game File Format Specification

struct SaveGame
{
    std::uint32_t xliveHeaderSize;
        // Always 4
        // Written by xlive
    std::uint32_t saveGameDataCRC32Checksum0;
        // Alternate CRC-32 Checksum of saveGameData taken as a raw byte buffer
        // Equals saveGameDataCRC32Checksum1
        // Written by xlive
    SaveGameData saveGameData;
        // 199996 bytes
    std::uint32_t saveGameDataCRC32Checksum1;
        // Alternate CRC-32 Checksum of saveGameData taken as a raw byte buffer
        // Equals saveGameDataCRC32Checksum0
};

struct SaveGameData 
{
    std::uint32_t dataCompressedSize;
        // Includes the sizes of dataCompressedSize and dataDecompressedSize
    std::uint32_t dataDecompressedSize;
    std::uint8_t data[dataCompressedSize - 4 - 4];
        // dataCompressedSize and dataDecompressedSize are part of the compressed data so we subtract their size from the data array
        // Data is compressed using Order 1 Arithmetic Coding
        // RTTI indicates that the implementation is a modification of the one presented at the end of
        // https://www.researchgate.net/publication/236980434_Arithmetic_Coding_revealed_-_A_guided_tour_from_theory_to_praxis#pf2f
    std::uint8_t zeros[199996 - 4 - 4 - dataCompressedSize - 1];
        // Filled with 0x00
        // Used to pad the SaveGameData structure size to 199996 bytes
    std::uint8_t version;
        // Always equals 61
};