Gets the number of streams in the current program of the specified streamType.


#include "ltmm.h"

C Syntax

HRESULT IltmmConvert_get_SourceStreamCount(pConvert, streamType, pVal)

C++ Syntax

HRESULT get_SourceStreamCount(streamType, pVal)

IltmmConvert *pConvert;

pointer to an interface

ltmmConvert_Stream streamType;

the stream type

long *pVal;

pointer to a variable




Pointer to an IltmmConvert interface.


The type of stream you're interested in. Currently, only two stream types are supported: Video (ltmmConvert_Stream_Video) and Audio (ltmmConvert_Stream_Audio).


Pointer to a variable to be updated with the number of streams of the specified streamType.



The function was successful.

<> S_OK

An error occurred. Refer to the Error Codes or the HRESULT error codes in the DirectShow documentation.


See the Programs and Streams topic for more information on programs and streams.

This property returns the number of streams of a particular type in the current program. You can then select which streams you wish to play by calling IltmmConvert::put_SelectedSourceStream.

If you change the current program using IltmmConvert::put_CurrentSourceProgram, the number of streams might change. So you will need to call IltmmConvert::get_SourceStreamCount again.

Required DLLs and Libraries


For a listing of the exact DLLs and Libraries needed, based on the toolkit version, refer to Files To Be Included With Your Application.


Win32, x64

See Also


IltmmConvert::put_SelectedSourceStream, IltmmConvert::get_SelectedSourceStream, IltmmConvert::get_SourceStreamCount, IltmmConvert::get_SourceProgramCount, IltmmConvert::put_CurrentSourceProgram, IltmmConvert::get_CurrentSourceProgram


Multimedia Function Groups

Programs and Streams
Closed Captioning


C++ example:

/* This example will select the last video and audio streams. There is no error checking to make the example easier to understand */ 
void SelectLastProgram(IltmmConvert *pConvert) 
   long SourceStreamCount = 0; 
   /* Select the last video stream - rarely necessary, since there is usually only one video stream */ 
   pConvert->get_SourceStreamCount(ltmmConvert_Stream_Video, &SourceStreamCount); 
   if(SourceStreamCount > 1) 
      pConvert->put_SelectedSourceStream(ltmmConvert_Stream_Video, SourceStreamCount - 1); 
   /* Select the last audio stream */ 
   pConvert->get_SourceStreamCount(ltmmConvert_Stream_Audio, &SourceStreamCount); 
   if(SourceStreamCount > 1) 
      pConvert->put_SelectedSourceStream(ltmmConvert_Stream_Audio, SourceStreamCount - 1); 

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LEADTOOLS Multimedia C API Help

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© 1991-2022 LEAD Technologies, Inc. All Rights Reserved.