Merge pull request #20210 from kstuedem:fix_invalid_media_type

modules/videoio/src/cap_dshow.cpp

@@ -2609,7 +2609,8 @@ static bool setSizeAndSubtype(videoDevice * VD, int attemptWidth, int attemptHei
         return true;
     }else{
         VD->streamConf->SetFormat(tmpType);
-        if( tmpType != NULL )MyDeleteMediaType(tmpType);
+        if( VD->pAmMediaType != NULL)MyDeleteMediaType(VD->pAmMediaType);
+        VD->pAmMediaType = tmpType;
     }
 
     return false;