((unsigned)((const uint8_t*)(x))[1] << 8) | \
(unsigned)((const uint8_t*)(x))[0]))
+/**
+ * Read a 64 bits big endian unsigned integer out of memory.
+ * @param x a pointer to the input memory
+ * @return the corresponding unsigned integer
+ */
+#define RB64(x) (((uint64_t)((const uint8_t*)(x))[0] << 56) | \
+ ((uint64_t)((const uint8_t*)(x))[1] << 48) | \
+ ((uint64_t)((const uint8_t*)(x))[2] << 40) | \
+ ((uint64_t)((const uint8_t*)(x))[3] << 32) | \
+ ((uint64_t)((const uint8_t*)(x))[4] << 24) | \
+ ((uint64_t)((const uint8_t*)(x))[5] << 16) | \
+ ((uint64_t)((const uint8_t*)(x))[6] << 8) | \
+ (uint64_t)((const uint8_t*)(x))[7])
+
/**
* Read a 32 bits big endian float out of memory.
* @param x a pointer to the input memory