IMFContentProtectionManager usage

[TetrisSQC]

Hi, did someone already wrote a small sample using DRM? Otherwise I will try to build one.

Christian

[FactoryXCode]

Hi Christian.
I don't think there's a sample in the pipeline.
So, a sample from you would be appreciated.
Tony.

[TetrisSQC]

FMX.MediaFoundation.pas.zip

Okay this version is a translation of this example:
https://github.com/GoshaDE/SuperMFLib/blob/master/samples/ProtectedPlayback/Player.cs

Further on It is a TControl derived component for Firemonkey. You can put all FMX components on it and they will be rendered over the video stream. It allows you to paint an OSD without any performance loss. Anyhow I did not got the DRM class working. It seem to be that it won't be called at all. Maybe somebody can have a look on it?

[FactoryXCode]

I don't think this the compleet sample is it?

[TetrisSQC]

To complete the sample, you just have to create an empty project and add a:
FPlayer := TMediaEngine.create(self);
FPlayer.parent := self;
FPlayer.Align := TFMXAlignLayout.Client;
FPlayer.Filename := 'MyFile';
FPlayer.Play;

I wrote a player it should be found in the post below.

[TetrisSQC]

fmx player.zip
The attached zip contain a player with an simple overlay running using Firemonkey.

I tried to keep it as simple as possible. Anyhow DRM does not seem to work. If the application crash it is most likely this line:
(FMediaEngine as IMFMediaEngineProtectedContent).SetContentProtectionManager(FContentProtectionManager);
It happen from time to time, but I do not see what I did wrong while implementing the ContentProtectionManager interface.

Christian

[FactoryXCode]

Ok , I tested the sample.
This what's changed & fixed:

Reformatted the code.
Fixed memory leaks
Fixed wrong project code (Form3 issue)
Tested the sample and no issues you mentioned happens.

Open issues:
The alignments of the layEPGCenter etc. labels are not correct when not full screen, in full screen mode they appears to be
aligned correctly.

Conclusion: FMediaEngine as IMFMediaEngineProtectedContent).SetContentProtectionManager(FContentProtectionManager; works as expected. (no return code different from S_OK) and is called on initialization without errors.

The corrected sample code has been put here.

Maybe the code you wrote for your project differs from the code of this sample?

Regards, Tony.

[TetrisSQC]

Thanks,
yes I did not checked possible leaks at this point. The epg was just an example - the whole scaling is done by the TScaledLayout class. Once I got DRM working I will build a more useful example.
I think I found the reason for my crashes. The main development here is done on a Mac using Parallels with an Windows 10 VM and it crashes in the graphic driver.
Besides this the DRM interface should be called if you for example want to play a stream like this one:
http://profficialsite.origin.mediaservices.windows.net/c51358ea-9a5e-4322-8951-897d640fdfd7/tearsofsteel_4k.ism/manifest(format=mpd-time-csf)

Not sure if the MF_MEDIA_ENGINE_CONTENT_PROTECTION_MANAGER should be used instead.

Christian

[FactoryXCode]

Not sure if the MF_MEDIA_ENGINE_CONTENT_PROTECTION_MANAGER should be used instead.

According to this article, you have.

Also: function MFCreatePMPMediaSession() is not implemented. To play DRM protected media, you have to initiate a PMP (Protected Media Path).

Usually, as I mentioned before, you should detect DRM protection first. However Microsoft say's this is optional, but make is easier to determine if a PMP or normal session would be needed.

A sample how to :

// If this function returns TRUE, it means the PMP is required for this presentation.
// Call MFCreatePMPMediaSession to create the PMP session object.
//
// If the function returns S_FALSE, you can use the unprotected pipeline.
// Call MFCreateMediaSession to create the regular Media Session object.
//
// Internally, this function checks whether any of the stream descriptors in the
// presentation have the MF_SD_PROTECTED attribute with the value TRUE.
function TContentProtectionManager.RequireDRMRights(): Boolean;
var
  hr: HResult;
  pPresentationDescriptor: IMFPresentationDescriptor;
  apStreamDescriptors: IMFStreamDescriptor;

begin

  hr := MFCreatePresentationDescriptor(0,
                                       @apStreamDescriptors,
                                       pPresentationDescriptor);



  hr :=  MFRequireProtectedEnvironment(pPresentationDescriptor);
  Result :=  Succeeded(hr);
end;

Regards Tony

[TetrisSQC]

Thanks,

but how do I use MFCreatePMPMediaSession together with the IMFMediaEngine? I tried play dash streams using the MFCreateMediaSession based projects instead of the IMFMediaEngine, but they fail playing these king of streams. They work with mp4 files, but everything else is not working.

Regards
Christian

[FactoryXCode]

Also what wonders me is that (FMediaEngine as IMFMediaEngineProtectedContent).SetOPMWindow(FWnd) returns E_NOTIMPL. While this function has to be called just before the command Play()

[TetrisSQC]

Yes, I stumbled over this also yesterday. You could use hr := li_Attributes.SetUINT64(MF_MEDIA_ENGINE_OPM_HWND, FWnd);
but this is probably the same and it seem to be that this is not implemented in the Mediafoundation. My second thought was to use MFCreatePMPMediaSession but IMFSourceResolver fails when it comes to Dash Urls. I also did not found a explanation how to handle Dashs in this mode in general. CreateObjectFromURL returns NS_E_SERVER_NOT_FOUND on every dash or hls stream I tested.

[FactoryXCode]

IMFSourceResolver fails when it comes to Dash Urls

The parameter pwszURL must be a local URL or URL. The function will not parse Object-URL (blob) data.

Regards, Tony.

[TetrisSQC]

These days I found time to work on this DRM related code a bit. It seem to be that you have to create a OPM window.

if not GetClassInfoEx(SysInit.HInstance,
    PChar('VirtualMediaFoundationCdmVideoWindow'), WindowClassEx) then
  begin
    FillChar(WindowClassEx, SizeOf(WindowClassEx), 0);
    WindowClassEx.cbSize := SizeOf(TWndClassEx);
    WindowClassEx.Style := CS_OWNDC;
    WindowClassEx.lpfnWndProc := @DefWindowProc;
    WindowClassEx.cbClsExtra := 0;
    WindowClassEx.cbWndExtra := 0;
    WindowClassEx.HInstance := SysInit.HInstance;
    WindowClassEx.hCursor := LoadCursorW(0, PChar(IDC_ARROW));
    WindowClassEx.hbrBackground := GetStockObject(BLACK_BRUSH);
    WindowClassEx.lpszMenuName := nil;
    WindowClassEx.lpszClassName :=
      PChar('VirtualMediaFoundationCdmVideoWindow');
    if WinApi.Windows.RegisterClassEx(WindowClassEx) = 0 then
      RaiseLastOSError;
  end;

  FVirtualWindow := CreateWindowEx(WS_EX_NOPARENTNOTIFY or WS_EX_LAYERED or
    WS_EX_TRANSPARENT or WS_EX_NOREDIRECTIONBITMAP, WindowClassEx.lpszClassName,
    '', WS_POPUP or WS_DISABLED or WS_CLIPSIBLINGS, 0, 0, 1, 1, 0, 0, 0, nil);

  li_Attributes.SetUnknown(MF_MEDIA_ENGINE_CALLBACK, self);
  li_Attributes.SetUINT64(MF_MEDIA_ENGINE_PLAYBACK_HWND, FWnd);
  li_Attributes.SetUINT64(MF_MEDIA_ENGINE_OPM_HWND, FVirtualWindow);
  li_Attributes.SetUINT32(MF_MEDIA_ENGINE_CONTENT_PROTECTION_FLAGS,
    MF_MEDIA_ENGINE_ENABLE_PROTECTED_CONTENT);
  li_Attributes.SetUnknown(MF_MEDIA_ENGINE_CONTENT_PROTECTION_MANAGER,
    FContentProtectionManager);

Anyhow the difference now is that if I add the protection manager the application crashes while loading drm encrypted content. I wonder why all the examples from Microsoft are UWP apps and it seem to be that they never really tested play ready with a "native" 32/64bit application.

[FactoryXCode]

Sorry to be a "bit" late...

I think FContentProtectionManager needs an implemented callback from the browser or object that is processing the URL. Microsoft has a sample to do this, but is based on Internet Explorer...

[FactoryXCode]

Any one else have an idea?