[Mp4-tech][H.264] about te(v)

[Xu Ke]

Dear experts,
In Page155 of 2003.5 standard,there are declaration about te(v):
"Otherwise (the syntax element is coded as te(v)), the range of the syntax element shall be determined first. The range of this syntax element may be between 0 and x, with x being greater than or equal to 1 and is used in the derivation of the value of a syntax element as follows"
Can anybody tell me how the variable "x" in the above is derived?
Many thanks in advance!
Best regards,
XU Ke