I need to iterate the IMFMediaSource pins and get the specific category name of each one of them, I am working in win 8, using the cpp interface of media foundation.
I saw that theres a IBaseFilter::EnumPins function for IBaseFilter, but IMFMediaSource dont support IBaseFilter interface :
CComPtr<IBaseFilter> pFilter;
HRESULT hr = m_pMediaSource->QueryInterface(__uuidof(IBaseFilter), (void **)&pFilter);
fails with NO_INTERFACE errorcode :(
how can I get the pins categories from a Media Source??
This does not work because it does not have to work. IMFMediaSource belongs to Media Foundation and IBaseFilter belongs to DirectShow. The different APIs don't have to share or otherwise duplicate implementation. Media Foundation objects don't even have pins to start with.
Since there can be no answer to the question asked, the only solution here is to step back and review what exactly you are trying to achieve in first place.
Related
I want to stream a preview video from my image sensor to my pc.
Later I want to add custom filters.
First I used Amcap to get a preview video. It works fine.
However I want my project to be baased on playcap (not as complicated as amcap).
When I start playcap it detects a device, however shows just a black screen.
I haven't modified the code in both examples.
Does anyone know how to fix this problem?
Or perhaps does anyone can describe how I can add a custom filter to amcap.
What does the Samplecgb part do in amcap?
King Regards,
afo
I'm going to try to distill the steps to creating a capture graph bellow. This is a complex process and usually there's multiple ways to accomplish most of the steps so you'll have to do your own research from here on and ask specific questions.
In the code snippets bellow I'll use _com_ptr_t smart pointers, which are defined using the _COM_SMARTPTR_TYPEDEF(IGraphBuilder, __uuidof(IGraphBuilder)) macro. So, do define the IGraphBuilderPtr you'd do something like this:
_COM_SMARTPTR_TYPEDEF(IGraphBuilder, __uuidof(IGraphBuilder))
// which defines IGraphBuilderPtr
You'll always need to have a graph so the first step is pretty universal:
IGraphBuilderPtr graph;
graph.CreateInstance(CLSID_FilterGraph);
Then, if you're building a capture graph, you'll most likely want to use the following interface:
ICaptureGraphBuilder2Ptr cg;
cg.CreateInstance(CLSID_CaptureGraphBuilder2);
cg->SetFiltergraph(graph);
After that, you'll need to add one or more input sources to the graph. You'll need to find the filter that wraps your image sensor as a video capture device and add that to the graph.
This is going to be a multi-step process which will likely involve doing something like this:
Enumerate all video capture devices:
IBaseFilterPtr fVideoInput; // will hold the video input source
ICreateDevEnumPtr pCreate(CLSID_SystemDeviceEnum);
IEnumMonikerPtr pEnum;
HRESULT hr = pCreate->CreateClassEnumerator(CLSID_VideoInputDeviceCategory,
&pEnum,
0);
if (hr == S_OK)
{
IMonikerPtr pMon;
while (pEnum->Next(1, &pMon, NULL) == S_OK)
{
// inspect the moniker of each devices to determine if it's the one you're after
// if it's the right device, then..
HRESULT hr = mon->BindToObject(NULL,
NULL,
__uuidof(IBaseFilter),
(void**)&fVideoInput);
}
}
Once you have the interface to the video input filter, you'll have to enumerate it's pins and find the correct output pin to connect the rest of the graph to. This can be as simple as enumerating all pins and picking the first output pin (if there is only one), or enumerating all pins and querying the media types of each output pin and selecting the right one that way, or, if you know the name of the pin (and it's always the same) calling FindPin. Below is an example of enumerating the pins and selecting the first output one:
IEnumPinsPtr pEnum;
fVideoInput->EnumPins(&pEnum);
IPinPtr pin;
while (pEnum->Next(1, &pin, NULL) == S_OK)
{
PIN_DIRECTION dir;
pin->QueryDirection(&dir);
if (dir == PINDIR_OUTPUT)
{
// this is the first output pin
break;
}
}
Once you have the output pin, you may insert another filter, find the appropriate pin (similar to above but looking for input pins) and then connect the two pins directly using:
// assuming pinOut is an output pin
// and pinIn is an input pin, this method will try to connect them
HRESULT hr = graph->Connect(pinOut, pinIn);
Or, you may try to simply render the pin:
hr = graph->Render(pinOut);
And here's an example of inserting a custom filter in the graph. If the filter is already registered in the system (it shows up in the list in GraphEdit) then all you need to know is the class id of the filter. This is a GUID that uniquely identifies the filter, and if you don't already know it, you can find it using GraphEdit (create new graph, insert the custom filter, right-click and see properties, there should be the class id of the filter):
IBaseFilterPtr fCustomFilter;
fCustomFilter.CreateInstance(__uuidof(CLSID_OF_YOUR_CUSTOM_FILTER));
graph->AddFilter(fCustomFilter, L"Custom Filter Name");
Then, you can proceed in a similar maner as above and find a suitable input pin for the filter, and a suitable output pin, and connect them as you see fit.
Finally, this is entirely optional, and only useful for debugging (so don't use in production), you can register the graph with the ROT to make it possible to study the final graph in a tool such as GraphEdit (or GraphStudioNext or the like).
Sample code take from MSDN for AddToROT and RemoveFromRot:
DWORD dwRegistration = 0;
HRESULT hr = AddToRot(graph, &dwRegistration);
// hold on to dwRegistration, and use it later when you tear down the graph
// to unregister it using the RemoveFromRot(&dwRegister) method
Currently I am working on embedding a HTML editor into a C++ WinAPI application using the MSHTML component.
I got everything set up (activating editing mode, changing font face, etc.), but now I have to support inserting images. MSHTML already has support for it built in, but this support is - to my knowledge - not enough.
Somehow I need a way to intercept the insertion of images into the HTML-editor, since I have to create a list of images in the UI of our application. So, whenever the user uses the default-dialog of the MSHTML-component to insert an image or updates its source (e.g. from file://xyz.jpg to file://abc.jpg), I want my code to be notified.
I already looked at the conecpt of "Edit Designers", the implementation of IHTMLEditHost, or the DWebBrowserEvents2 interface. But nothing seems to do the trick.
Perhaps someone can give me a hint?
Okay,
it looks like you cannot explicitly subscribe for specific changes of the document. What you can do is to create a so-called "Change Sink".
Everytime you change the document, either by user input or programmatically, you can get a notification that "something" changed in your document. This can be done by implementing the IHTMLChangeSink interface and attaching it to the IMarkupContainer2 of the IHTMLDocument2.
Example code (not complete):
class CHTMLChangeSink : public IHTMLChangeSink
{
public:
// Implement IUnknown: QueryInterface, AddRef, Release
// Implement IHTMLChangeSink:
HRESULT STDMETHODCALLTYPE Notify()
{
// Notify() is called everytime the document changes
return S_OK;
}
};
CHTMLChangeSink * pChangeSink = new CHTMLChangeSink();
IHTMLDocument2 * pDoc; // lets suppose we already have it
IMarkupContainer2 * pMarkupContainer = nullptr;
if (pDoc->QueryInterface(IID_IMarkupContainer2, reinterpret_cast<void **>(&pMarkupContainer)) == S_OK) {
DWORD dwCookie = 1;
// registration is done here
pMarkupContainer->RegisterForDirtyRange(pChangeSink, &dwCookie);
}
Please be aware, that the document has to be loaded completely (register for DIID_DWebBrowserEvents2::DocumentComplete).
From now on, whenever a change in the document occurs, your Notify-method will be called and you can do further processing to find out what has changed (e.g. process the list of images in the document).
Have fun!
Does anyone know which relation may exist between registration-free COM and drag/drop functionality?
Specifically, we have a huge C++ CAD/CAM application comprising a number of EXEs and several hundreds DLLs. Many of them serve as COM servers (both in-proc and out-of-proc) and/or clients, and also implement ActiveX controls.
The most of ActiveX controls and the main CMDIFrameWnd-based window of one of EXEs implement drag/drop functionality. ActiveX controls implement the both drop source and drop target, and the main window is only drop target, in particular, for files from Windows Explorer.
The drag/drop implementation is pretty standard and based on two data members derived from COleDataSource and COleDropTarget for drop source and drop target respectively. The COleDropTarget-derived member is registered with respective window in the window's OnCreate method. It also overrides OnDragEnter, OnDragOver and OnDrop methods in a similar way. Namely, the system-supplied COleDataObject parameter is asked for specific format (in particular, CF_HDROP), and in the case of positive answer, the data (e.g., file path) is extracted from the clipboard. The code looks like the following:
static FORMATETC g_FileFmt = {CF_HDROP, 0, DVASPECT_CONTENT, 0, TYMED_HGLOBAL};
....
// Inside OnDragEnter, OnDragOver or OnDrop method
STGMEDIUM stgmedium = {0,0,0};
if (pDataObject->IsDataAvailable(g_FileFmt.cfFormat))
{
HRESULT hr = pDataObject->GetData(g_FileFmt.cfFormat, &stgmedium);
HDROP hdrop = (HDROP)GlobalLock(stgmedium.hGlobal);
if (hdrop != 0)
{
int FilesCount = DragQueryFile(hdrop, (UINT)-1, 0, 0);
if (FilesCount != 0)
{
TCHAR FileName[_MAX_PATH];
DragQueryFile(hdrop, 0, FileName, _MAX_PATH);
// Check file extension and store the file name for farther use.
}
GlobalUnlock(hdrop);
}
}
The drop source implementation is also straightforward and looks like the following:
void CDmDocListCtrl::OnBeginDrag(NMHDR* pNMHDR, LRESULT* pResult)
{
NM_LISTVIEW* pNMListView = (NM_LISTVIEW*)pNMHDR;
if (pNMListView->iItem != -1 && m_pOleDataSource && prv_BeginDrag())
{
DROPEFFECT DE = m_pOleDataSource->DoDragDrop(
DROPEFFECT_COPY | DROPEFFECT_MOVE | DROPEFFECT_LINK, 0);
}
*pResult = 0;
}
where prv_BeginDrag() function collects dragged data, packs it and puts on the clipboard by calling SetData method from the m_pOleDataSource object's IDataObject interface.
The all this stuff worked perfectly until it was decided to make the whole application registration-free. It took me three months to force the application run isolated (without registration of COM components) by embedding manifests, launching out-of-proc COM servers on demand and altering CLSID of some classes in order to separate instances of the same server launched from different folders. At last it begins to work - but without drag/drop functionality, despite it wasn't even touched by my changes.
On the drop target side, when I drag file from Windows Explorer, depicted above call to COleDataObject::IsDataAvailable returns false, although before my changes returned true. At the same time, if I add a single line of code "DragAcceptFiles();" to the main window's OnCreate method, drag/drop begins working via the standard CFrameWnd's WM_DROPFILE message handler.
On the drop source side, the dragged data are successfully packed and placed on the clipboard, but COleDataSource::DoDragDrop method fails, because a call to ::DoDragDrop API inside MFC implementation returns REGDB_E_CLASSNOTREG "Class not registered" result.
It means, that COM activation changes somehow influence drag/drop behavior. How?
P.S. 1) The EXE, to which I drag files from Windows Explorer, has in its project properties "UAC Execution Level = asInvoker". As far as I understand, it tells that the EXE will run at the same UAC level as Windows Explorer when launched by double-click on the file.
2) Quite surprisingly, although drag/drop stopped working with symptoms described above, Copy/Paste continues work well, despite the both technologies have similar implementation.
3) I believe, that if find out when ::DoDragDrop API returns "Class not registered" error, and which class it is looking for, it would be possible to solve the problem.
Thanks for help,
Ilia.
Following to MartinBa advice, I solved the problem with the help of Process Monitor. The Process Monitor showed me that while I drag an item in the ActiveX control (mentioned in the question), the system unsuccessfully tries get access to a class ID in the Registry. Looking for that ID, I found that it is really not class ID, but IDataObject interface ID. It was referenced in one of my manifest files.
The most of manifests I have written by hand, but a few, especially at the beginning of the project having no experience in the area, I generated automatically by Visual Studio from existing type library. In one of them Studio included the comInterfaceExternalProxyStub statement for a couple of system interfaces, in which proxyStubClsid32 element was (erroneously) equal to the interface ID.
I'm still not sure whether those system interfaces should present in the manifest; for example, the IDataObject is only mentioned as a method's parameter in one of IDL definitions. Anyway, I corrected only the proxyStubClsid32 value, and the problem disappeared...
The moral of this very painful for me story is to always check output of automatic tools...
I've written a custom renderer filter to push video frames to system memory and later to OpenGL. It's not in a DLL and I don't register it, but instead use it like this page describes in the first paragraph. This works fine in the Debug mode, but in Release it starts crashing. I'm doing the following to initialize the graph:
HRESULT hr;
CoInitialize(0);
CoCreateInstance(CLSID_FilterGraph, 0, CLSCTX_INPROC, IID_IGraphBuilder, (void**)&graph);
graph->QueryInterface(IID_IMediaControl, (void**)&mediaControl);
graph->QueryInterface(IID_IMediaSeeking, (void**)&mediaSeeking);
grabber = new textureGrabber(0, &hr);
grabber->AddRef(); // crash here
grabber->setTexture(&texture);
grabber->QueryInterface(IID_IBaseFilter, (void**)&base);
graph->AddFilter(base, L"OpenGL texture video filter");
graph->RenderFile(path.c_str(), 0);
This crashes on the AddRef() due to an access violation. I've already tried implementing the IUnknown of the class myself, and the best I got was to the AddFilter where it crashed because the IBaseFilter seemed to be invalid. After that I found even a Microsoft-issued example doing this the simple way and it seems to work for them. I'm curious what might be wrong since I'm doing the same exact thing - even tried the smart pointers.
EDIT: The problem is in the CBaseFilter DECLARE_IUNKNOWN macro, the GetOwner()->AddRef fails. GetOwner itself seems to work.
GetOwner returns whatever you pass as the second parameter to the CBaseFilter constructor. Normally NULL unless you are aggregating the object for some reason (if you are, you probably don't need to).
A crash can occur at that point if your release build is linking against Strmbasd.lib, which is the debug version of the DirectShow base class library.
Change your project's release configuration to link against Strmbase.lib instead, which is the release version of the library.
The MSDN documentation on WebBrowser Customization explains how to prevent new windows from being opened and how to cancel navigation. In my case, my application is hosting an IWebBrowser2 but I don't want the user to navigate to new pages within my app. Instead, I'd like to open all links in a new IE window. The desired behavior is: user clicks a link, and a new window opens with that URL.
A similar question was asked and answered here and rather than pollute that answered post, it was suggested I open a new discussion.
The members on the related post suggested I should be able to do this by trapping DISPID_BEFORENAVIGATE2, setting the cancel flag, and writing code to open a new window, but I've found out that the browser control gets lots of BeforeNavigate2 events that seem to be initiated by scripts on the main page. For example, amazon.com fires BeforeNavigate2 events like crazy, and they are not a result of link invocation.
Replies appreciated!
What I ended up doing was using IHTMLDocument directly rather than IWebBrowser. IWebBrowser is a superset of IHTMLDocument, and the navigation model implemented by IWebBrowser isn't customizable to the degree I wanted.
I actually got MS Developer Support involved and this approach was their recommendation. They say this is what Outlook uses for HTML-based email, which is the user experience I wanted to emulate. They also confirmed that there's no reliable way to filter the OnBeforeNavigate events that result from user action from those that result from script activity.
Hope this helps anybody facing the same issues. It wasn't too hard to port the code to use IHTMLDocument. If you end up doing this, you may also find yourself looking for a way to figure out when the document is done loading. To do that, hook HTMLDocumentEvents instead of DWebBrowserEvents, and look for the DISPID_HTMLDOCUMENTEVENTS_ONREADYSTATECHANGE event. It doesn't tell you what the ready state is; you need to call IHTMLDocument::get_readyState and parse the resulting string. Goofy, but there you go.
You can bind to onclick event before document is complete while creating browser in OnCreate() using IHTMLDocument2::put_onclick():
#include <comutil.h>
ClickEvents<RootFrame> clickEvents;
_variant_t clickDispatch;
clickDispatch.vt = VT_DISPATCH;
clickDispatch.pdispVal = &clickEvents;
CComQIPtr<IDispatch> dispatch;
hr = webBrowser2->get_Document(&dispatch);
ASSERT_EXIT(SUCCEEDED(hr), "webBrowser->get_Document(&dispatch)");
CComQIPtr<IHTMLDocument2> htmlDocument2;
hr = dispatch->QueryInterface(IID_IHTMLDocument2, (void**) &htmlDocument2);
ASSERT_EXIT(SUCCEEDED(hr), "dispatch->QueryInterface(&htmlDocument2)");
htmlDocument2->put_onclick(clickDispatch);
ClickEvents class implements IDispatch, you only need to implement Invoke method, in rest return E_NOTIMPL:
HRESULT STDMETHODCALLTYPE Invoke(DISPID dispIdMember, REFIID riid, LCID lcid, WORD wFlags,
DISPPARAMS *pDispParams, VARIANT *pVarResult, EXCEPINFO *pExcepInfo, UINT *puArgErr)
{
HRESULT hr;
CComQIPtr<IWebBrowser2> webBrowser2;
hr = rootFrame->GetDlgControl(rootFrame->rootview.GetDlgCtrlID(), IID_IWebBrowser2, (void**) &webBrowser2);
ASSERT_EXIT(SUCCEEDED(hr), "rootframe->GetDlgControl(IID_IWebBrowser2) failed");
CComQIPtr<IDispatch> dispatch;
hr = webBrowser2->get_Document(&dispatch);
ASSERT_EXIT(SUCCEEDED(hr), "webBrowser2->get_Document(&dispatch)");
CComQIPtr<IHTMLDocument2> htmlDocument2;
hr = dispatch->QueryInterface(IID_IHTMLDocument2, (void**) &htmlDocument2);
ASSERT_EXIT(SUCCEEDED(hr), "dispatch->QueryInterface(&htmlDocument2)");
CComQIPtr<IHTMLWindow2> htmlWindow2;
hr = htmlDocument2->get_parentWindow((IHTMLWindow2**) &htmlWindow2);
ASSERT_EXIT(SUCCEEDED(hr), "htmlDocument2->get_parentWindow(&htmlWindow2)");
CComQIPtr<IHTMLEventObj> htmlEvent;
hr = htmlWindow2->get_event(&htmlEvent);
ASSERT_EXIT(SUCCEEDED(hr), "htmlWindow2->get_event(&htmlEvent)");
CComQIPtr<IHTMLElement> htmlElement;
hr = htmlEvent->get_srcElement(&htmlElement);
ASSERT_EXIT(SUCCEEDED(hr), "htmlEvent->get_srcElement(&htmlElement)");
CComBSTR hrefAttr(L"href");
VARIANT attrValue;
VariantInit(&attrValue);
hr = htmlElement->getAttribute(hrefAttr, 0 | 2, &attrValue); // 0 = case insensitive, 2 = return BSTR
ASSERT_EXIT(SUCCEEDED(hr), "htmlElement->getAttribute()");
wchar_t href[2084]; // maximum url length in IE, http://support.microsoft.com/kb/208427
wcsncpy_s(href, _countof(href), attrValue.bstrVal, _TRUNCATE);
if (!rootFrame->IsURLAllowed(href)) {
VARIANT variant;
variant.vt = VT_BOOL;
variant.boolVal = VARIANT_FALSE;
htmlEvent->put_returnValue(variant);
ShellExecute(0, L"open", href, 0, 0, SW_SHOWNORMAL);
}
return S_OK;
}
As you can see after querying some interfaces I finally have the element that got clicked, then I call IsURLAllowed() defined in my root frame to check whether to allow opening url in current webbrowser window or whether to open it using default browser on user's computer.
This handles all links even if they were appended to document using javascript.
The same should be done with "onsubmit" events for forms.
I also think I have a solution for "window.location" redirects in javascript, I haven't tested it yet, but I will soon test it and I will update this answer then. You could use a combination of "onunload" and "onbeforeunload" events along with DWebBrowserEvents2::BeforeNavigate2(), after onunload/onbeforeunload are called you will know that user is leaving current page so now in BeforeNavigate2() you can cancel it. You can attach unload events using IHTMLWindow2::put_onunload() and IHTMLWindow2::put_onbeforeunload().
See sources of a complete solution for the "onclick" below.
AttachClickEvents in BrowserFrame:
http://code.google.com/p/phpdesktop/source/browse/phpdesktop-msie/msie/browser_frame.h?r=709d00b991b5#125
Invoke in ClickEvents(IDispatch):
http://code.google.com/p/phpdesktop/source/browse/phpdesktop-msie/msie/click_events.h?r=a5b0b350c933#132
I'm hypothesising here but yet another approach could be to maintain a count of navigation events, incrementing the counter on DISPID_BEFORENAVIGATE2 and decrementing it on occurrences of DISPID_NAVIGATECOMPLETE2 and DISPID_NAVIGATEERROR. With that in place, you could speculate that whenever you get DISPID_BEFORENAVIGATE2 and your counter is at zero, it is actual user navigation / link invocation.
I have no idea whether this approach would work, or whether those are the right events you'd need to make it work, but it could be worth investigating.
You could try a different approach instead and physically add the attribute target="_blank"
to all <a> tags in the rendered document.
This approach would involve waiting for DISPID_DOCUMENTCOMPLETE and then using IHTMLDocument3::getElementsByTagName() to fetch all of the anchor elements. You would then use IHTMLElement::setAttribute() to set target="_blank" on each of them.
It seems to me, that it you want "to open all links in a new IE window", it means that you want that the opening of new windows must be done in another process. The easiest way to do so: using CreateObject("InternetExplorer.Application") way (see another question which solve a problem, which is opposite to your question: InternetExplorer.Application object and cookie container). With this way you will receive the best isolation from your application and the user who clicks on the link receive all possibilities which exist in IE. You should of cause continue usage of BeforeNavigate2 events to find out the moment when "a new IE window" should be opened.