The Wxutil.h header file in the DirectShow base classes provides some mathematical helper functions. These are intended to help with time format conversions.
| Function | Description |
| llMulDiv | Implements ((a*b)+rnd)/c for 32-bit values of a. |
| Int64x32Div32 | Implements ((a*b)+rnd)/c for 64-bit values of a. |
Multiplies a by b, adds rnd to the 128-bit result, then divides by c.
LONGLONG WINAPI llMulDiv(
LONGLONG a,
LONGLONG b,
LONGLONG c,
LONGLONG rnd
);
Returns either the (a * b + rnd)/c calculation or one of the following values.
| Value | Condition |
| 0x7FFFFFFFFFFFFFFF | Overflow occurred because the result is too large (positive). |
| 0x8000000000000000 | Overflow occurred because the result is too large (negative). |
Rounding on the division is toward zero. Division by zero is counted as an overflow condition.
Multiplies a by b, adds rnd to the 96-bit result, then divides by c.
LONGLONG WINAPI Int64x32Div32(
LONGLONG a,
LONG b,
LONG c,
LONG rnd
);
Returns either the (a * b + rnd)/c calculation or one of the following values.
| Value | Condition |
| 0x7FFFFFFFFFFFFFFF | Overflow occurred because the result is too large (positive). |
| 0x8000000000000000 | Overflow occurred because the result is too large (negative). |
Rounding on the division is toward zero. Division by zero is counted as an overflow condition.
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