Retrieving Media File Information for C++
This simple C++ example for using the ltmmMediaInfo object retrieves the source file properties and displays them in message boxes.
#include "ltmm.h"
#include <atlbase.h>
#include <atlconv.h>
void AddStringToMsg(char *pszTitle, BSTR sString, char *pszMsg);
void AddNumberToMsg(char *pszTitle, double dNumber, char *pszMsg, BOOL
bFloat);
int main()
{
IltmmMediaInfo *pMediaInfo;
BSTR sString;
char szMsg[8196];
long lStreams, lIndex, l;
double d;
CoInitialize(NULL);
// create an ltmmMediaInfo object:
HRESULT hr = CoCreateInstance(CLSID_ltmmMediaInfo, NULL,
CLSCTX_INPROC_SERVER, IID_IltmmMediaInfo,
(void**)
&pMediaInfo);
memset(szMsg, 0, 8196);
// set the source file:
sString = SysAllocString(L"C:\\Test.avi");
pMediaInfo->put_SourceFile(sString);
SysFreeString(sString);
// general properties:
pMediaInfo->get_SourceFile(&sString);
AddStringToMsg("Source file: ", sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_SourceFileSize(&d);
AddNumberToMsg("File size: ", d, szMsg, FALSE);
pMediaInfo->get_OutputStreams(&lStreams);
AddNumberToMsg("Number of streams: ", (double)lStreams,
szMsg, FALSE);
pMediaInfo->get_SourceDuration(&d);
AddNumberToMsg("File duration: ", d, szMsg, TRUE);
pMediaInfo->get_SourceBitRate(&l);
AddNumberToMsg("Source BitRate : ", (double)l, szMsg,
FALSE);
pMediaInfo->get_SourceFormat(&l);
AddNumberToMsg("Source format: ", (double)l, szMsg,
FALSE);
pMediaInfo->get_SourceFormatName(&sString);
AddStringToMsg("Source format name: ", sString,
szMsg);
SysFreeString(sString);
pMediaInfo->get_SourceFilterClassID(&sString);
AddStringToMsg("Source filter CLSID: ", sString,
szMsg);
SysFreeString(sString);
pMediaInfo->get_SourceFilterName(&sString);
AddStringToMsg("Source filter name: ", sString,
szMsg);
SysFreeString(sString);
pMediaInfo->get_Title(&sString);
AddStringToMsg("Title The name for a group of related video files (called "Chapters") on your DVD. For example, for a DVD called "My Summer Vacation," you might have the titles "Water Skiing," "New Friends," and "Hiking." For each of those titles, you might have one or more different video files.: ", sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_Author(&sString);
AddStringToMsg("Author: ", sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_Description(&sString);
AddStringToMsg("Description: ", sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_Rating(&sString);
AddStringToMsg("Rating: ", sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_Copyright(&sString);
AddStringToMsg("Copyright: ", sString, szMsg);
SysFreeString(sString);
MessageBox(0, szMsg, "MediaInfo Sample: General...",
0);
// stream properties:
for( lIndex=0; lIndex<lStreams; lIndex++ )
{
memset(szMsg, 0, 8196);
pMediaInfo->put_CurrentStream(lIndex);
pMediaInfo->get_CurrentStream(&l);
AddNumberToMsg("Stream number: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_StreamType(&sString);
AddStringToMsg("Stream type: ",
sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_StreamTypeName(&sString);
AddStringToMsg("Stream type name: ",
sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_StreamSubtype(&sString);
AddStringToMsg("Stream subtype: ",
sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_StreamSubtypeName(&sString);
AddStringToMsg("Stream subtype name:
", sString, szMsg);
SysFreeString(sString);
pMediaInfo->get_StreamDuration(&d);
AddNumberToMsg("Stream duration: ",
d, szMsg, TRUE);
// video specific
strcat(szMsg, "\n");
strcat(szMsg, "\t*** Video specific
properties ***\n");
pMediaInfo->get_VideoFrameRate(&d);
AddNumberToMsg("Video frame rate: ",
d, szMsg, TRUE);
pMediaInfo->get_VideoWidth(&l);
AddNumberToMsg("Video width: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_VideoHeight(&l);
AddNumberToMsg("Video height: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_VideoBitCount(&l);
AddNumberToMsg("Video bit count: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_VideoCompression(&l);
AddNumberToMsg("Video compression:
", (double)l, szMsg, FALSE);
pMediaInfo->get_VideoBitRate(&l);
AddNumberToMsg("Video bit rate: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_VideoFrames(&l);
AddNumberToMsg("Video frames count:
", (double)l, szMsg, FALSE);
// Audio specific
strcat(szMsg, "\n");
strcat(szMsg, "\t*** Audio specific
properties ***\n");
pMediaInfo->get_AudioFormatTag(&l);
AddNumberToMsg("Audio format tag: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_AudioChannels(&l);
AddNumberToMsg("Audio channels: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_AudioSamplesPerSec(&l);
AddNumberToMsg("Audio frequency: ",
(double)l, szMsg, FALSE);
pMediaInfo->get_AudioBitsPerSample(&l);
AddNumberToMsg("Audio sample size:
", (double)l, szMsg, FALSE);
pMediaInfo->get_AudioAvgBytesPerSec(&l);
AddNumberToMsg("Audio average bytes
per second: ", (double)l, szMsg, FALSE);
MessageBox(0, szMsg, "MediaInfo Sample:
Streams...", 0);
}
pMediaInfo->ResetSource();
pMediaInfo->Release();
CoUninitialize();
return 0;
}
void AddStringToMsg(char *pszTitle, BSTR sString, char *pszMsg)
{
USES_CONVERSION;
strcat(pszMsg, pszTitle);
if( sString )
strcat(pszMsg, W2A(sString));
else
strcat(pszMsg, "NA");
strcat(pszMsg, " \n");
}
void AddNumberToMsg(char *pszTitle, double dNumber, char *pszMsg, BOOL
bFloat)
{
char szNumber[64];
if( bFloat )
sprintf(szNumber, "%f", dNumber);
else
sprintf(szNumber, "%.f", dNumber);
strcat(pszMsg, pszTitle);
strcat(pszMsg, szNumber);
strcat(pszMsg, " \n");
}