ref_vfmethod_stringProc - shekh/VirtualDub2 GitHub Wiki

VirtualDub Plugin SDK 1.2

stringProc video filter method

stringProc

Creates a user-readable string description of the filter instance's current configuration.

void stringProc(const VDXFilterActivation *fa, const VDXFilterFunctions *ff, char *buf);

Parameters

fa	Pointer to filter activation structure.
ff	Pointer to callback function structure.
buf	128-byte buffer to receive string. This includes the terminating null, so only 127 characters may be placed.

Thread safety

This method is not thread-safe.

Exceptions

This function must not throw exceptions (see Except()).

API version requirement

Ignored starting with V16.

Default behavior

If omitted, no default action is taken.

Remarks

Unfortunately, the length of the buffer is not passed to the filter. In VirtualDub 1.4d, this filter is a fixed-length 128-byte global buffer, but the beginning of the buffer is pre-filled with the input/output sizes and the name of the filters, so no more than 80 bytes of space is reliably available. Use the _snprintf() and _vsnprintf() functions to make sure you do not overrun the buffer. Like paramProc, this function is called relatively frequently in the user interface, so it shouldn't take too long.

Also, note that limited space is available in VirtualDub's filter list, and that the list does not scroll horizontally, so keep your descriptions short! The string is purely informative, so you do not need to show all of your filter's parameters.

New filters should supply both this function and stringProc2; the only difference is that stringProc2 receives a buffer length.