Debug Output

The debug output facility is just one of several facilities of debug logging available with Microsoft® DirectShow®. This facility is monolithic (that is, it is either on or off). For information about the facility with the most precise control enabling and disabling logging, see Debug Logging by Module Level. For information about the simplest facility, see Debug NOTE (Message) Macros.

For more information about how DbgOutString chooses the debug output location, see Debug Output Location. DbgInitialise opens the debug output location and DbgTerminate closes it.

DbgOutString Sends a debug string to the debug output location.
DumpGraph Sends debugging information from the filter graph to the debug output location.

DbgOutString

Debug Output

Sends the given string to the debug output location.

Syntax

void WINAPI DbgOutString(
    LPCTSTR psz
    );

Parameters

psz
Pointer to a string to be output.

Remarks

DbgOutString is ignored unless DEBUG is defined when the DirectShow headers are included. That is, it is a function in a debug build, and a macro that does nothing in other builds.

DumpGraph

Debug Output

Sends debugging information from the filter graph to the debug output location.

Syntax

void WINAPI DumpGraph(
    IFilterGraph *pGraph,
    DWORD dwLevel
    )

Parameters

pGraph
Pointer to the filter graph to get debugging information about.
dwLevel
Logging level for this message, where zero means always log.

Remarks

Call this helper function to send potential error messages after you instantiate a filter graph.

DbgOutString	Sends a debug string to the debug output location.
DumpGraph	Sends debugging information from the filter graph to the debug output location.