Asobo Save Game File Format Specification

struct SaveGame
{
    std::uint32_t four;
        // Always 4
        // Written by xlive
    std::uint32_t bufferCRC32Checksum0;
        // CRC-32 Checksum of the buffer
        // Equals bufferCRC32Checksum1
        // Written by xlive
    std::uint8_t buffer[199996];
        // Contains 1 SaveGameData starting at &buffer[0] and filling the buffer
    std::uint32_t bufferCRC32Checksum1;
        // CRC-32 Checksum of the buffer
        // Equals bufferCRC32Checksum0
};

struct SaveGameData
{
    std::uint32_t dataCompressedSize;
    std::uint32_t dataDecompressedSize;
    std::uint8_t data[dataCompressedSize - 8];
        // dataCompressedSize and dataDecompressedSize are part of the compressed data so we subtract their size from the data array
        // Data is compressed using ArithmeticCoderC
        // They stole it from https://www.researchgate.net/publication/236980434_Arithmetic_Coding_revealed_-_A_guided_tour_from_theory_to_praxis#pf2f
    std::uint8_t zeros[199996 - dataSize - 1];
        // Filled with 0x00
    std::uint8_t equals61;
        // Always equals 61
};