I am pretty new to DirectShow and really just feeling my way round at the moment. I am wanting to host the directshow renderer window of a directshow graph within a WPF app and am currently using the HwndHost class to try to achieve this. What I need though for HwndHost is a handle to the window which is rendering the video. I have found an example which shows getting the handle by enumerating the pins of an IVideoWindow interface and querying for IOverlay so the GetWindowHandle method can be used to get the handle.
Problem is IOverlay doesnt seem to be available in DirectShow.Net. Reading the DirectShow.Net About page, IOverlay is listed in the table with the heading "These interfaces are in the source code, but are deprecated, undocumented, intended for Ole Automation or otherwise untestable which means they are not, and will not be tested".
So what is it that I have to do to get access to this definition? Is it excluded from the build that is distributed as a library and so should I build the library from source myself?
OR Is there a better way of doing what I am trying to do? Anyhelp would be appreciated as like I said I am new to all this stuff.
Thanks in advance.
EDIT: Not many DirectShow devs out there? Or is this a stupid question, definitely open to any advice peeps may have...
The normal way to do this is to reparent the video window using IVideoWindow::put_Owner to make it a child of your own window. You will also want to set the AutoShow (false), Visible, Width and Height properties, and change the WindowStyle property to make it a child window.
The IOverlay interface was implemented in the first version of DirectShow (1996) to support some hardware decoders that are long since defunct. I don't think the current video renderers will support it.
The window handle was made difficult to obtain because poor application programming caused frequent deadlocks in Video for Windows and the developers felt that a clear separation was needed between the DirectShow threads and the windows they owned, and any application threads.
G
Related
How do you put a Windows Form Application on top off everything on your screen?
Just setting the topmost-property isn't enough when you're running fullscreen games.
If anyone has a solution for good old Forms i'll also be happy
I've seen many posts on this forum that say it's impossible but i know it's not couse i've seen alot of apps (fraps, teamspeak overlay, xfire, etc) that does this.
If you want to use a graphics library to display something always on screen, you may want to start here on SO. There are wrapper libraries available like OpenTK for OpenGL. If you want to go the DirectX route you'll need to load in the C++ libraries and access them using P/Invoke. There's a good tutorial to start with on msdn. Wrappers for DirectX also exist in the form of SharpDX.
I am writing a C# Windows Form application which communicates with a webcam.
However, I want to tune webcam properties inside a button click function. Examples of those properties are brightness, saturation and sharpness.
I have found IAMVideoProcAmp::Set which might aid me with this. However, I don't quite understand how to implement this.
Can anyone help me in the right direction?
What you'll need to do is wrap calls to certain APIs (whether it's Windows, DirectX, etc) which is easier said than done when it comes to C#.
Luckily this problem has been solved numerous times (as you can see by number of webcam questions here) - and you can find one good approach in the following article:
Versatile WebCam C# library
Check out "How to change contrast and saturation programmatically?"
Lately, I've been trying to setup a media center PC. I've played around with all the common media center applications like XBMC, Plex, Boxee, and WMC. But all of them have one issue or another. So I was thinking about writing my own application from scratch.
My problem is I have no experience with developing software that plays media such as videos or music. I'm also not interested in spending a huge amount of time trying to figure this out, considering all the different file formats and codecs out there. I'm really more interested in developing the database and library interface for my application and reusing someone else's control or code for actually playing the media.
One option I was thinking was to just control an existing media player externally. So for example you may browse for a video to play in my application, and then when you hit play it would fire up VideoLAN or some other popular video player.
However, I was wondering if there was an easy way to play video inside a .NET application. I'm looking for something that is capable of playing a wide variety of formats such as MKV files, and DVD ISOs. I'm more experience with WinForms, but was also thinking about using this project as an opportunity to learn WPF.
i've spent many years looking at playing video under wpf.
The short answer
There is no easy way to guarantee to be able to play a variety of formats under wpf ( mkv,dvd etc etc ) or under windows for that matter.
the long answer
If you are looking just to run this at home and not release it, install all the codecs you need and most of the formats will run via mediaelement in wpf.
Getting all the codecs to cooperate can sometimes be frustrating.
Now moving into slightly harder territory.
if you want to play DVD then you need to replace mediaelement with wpfmediakit
http://wpfmediakit.codeplex.com/
wpfmediakit gives a base library to get access to the low level directshow functionality.
There is already a code base for playing DVDs based on wpfmediakit.
Now moving onto the very hard territory.
if you want to distribute your application and have users be able to "just watch" most/all media formats means you need to be able to completely control their codecs, which generally means distributing the codecs with your package and building the directshow filter graph in code rather than let windows build it.
The easiest way is to use the existing .Net hooks to Microsoft's standard MediaPlayer:
http://msdn.microsoft.com/en-us/library/system.windows.media.mediaplayer.aspx
http://msdn.microsoft.com/en-us/library/windows/desktop/dd562851%28v=vs.85%29.aspx
was trying myself a while ago for something to play media in winforms, and found out there is vlc wrappers for .Net, dunno how good they are as i gave up, but you can try
here is one them:
http://vlcdotnet.codeplex.com/
Thanks for all the great answers. But just found out that VLC can actually be controlled through HTTP. So I think I'm just going to use that to point an instance of VLC running with the HTTP interface at whatever file I want to play.
Does anyone know how to apply effects to the entire screen, in c# or any programming language.
I'm mostly interested in making the screen monochrome (specifically green-white instead of black white).
I know a cross-graphic card solution is possible because I found a program that can do it:
http://www.freedomscientific.com/products/lv/magic-bl-product-page.asp
Anyone knows how to accomplish something this or where to look?
Thanks !!
There is no easy Windows API to modify the entire screen contents. But this could be done at the device driver level.
Otherwise you have to resort to some Windows API tricks: place a "fake" window over the entire desktop, in a loop: grab the entire screen contents without grabbing fake window contents, do your processing to get the monochrome effect, then display that on the fake window. Yes, it's hacky and slow, but possible. Even more hacky, when you get mouse clicks to "go through" the fake window (lots of SetWindowsRgn calls).
So cross-platform here means using GDI, though some older DirectDraw APIs might work, in that case, you have a much easier time with hardware overlays (and better performance). Though I'm not sure how many cards actually support hardware overlays, and if newer versions of windows support the older DirectDraw APIs.
One more possibility is if the video card has a C# or C++ or C API, then you can do whatever you want with the card without writing device driver code.
Then there's CUDA, but I haven't yet tried that out. I know it's for stream processing on nVidia boards, but I wonder if it could get you an easy backdoor into the video display stuff.
To help people in the future who are interested in this:
This is possible with the Magnification API's color effect method. This allows one to use a matrix that can be applied to the whole screen.
NegativeScreen is an open source project that implements the feature you are describing in C#.
Unfortunately, this only works with affine transformations, as the API takes only an augmented matrices rather than a delegate or something.
Windows API
So i know that the WinForms touches on the Windows API a little, but frankly its horrible. ESPECIALLY with the layered windows and flickering. So i was wondering if anyone has wrote partial, or full wrappers for the Windows API.Im particularly interested in the Layered Window aspect, but really any part of the API is a good place to start.
Update: I found the Windows API Code Pack here: http://code.msdn.microsoft.com/WindowsAPICodePack but it seems that it doesnt wrap Layered Windows? Am i correct in assuming this?
Native API (Windows)
Ive heard a little bit about the Native API, but im not quite sure what it is for? what features does it provide? would it be a good idea to look into?
Summary (Questions in a nutshell)
Does anyone know of an existing (partial or full) wrapper of the Windows API?
If the answer is no to question one, where would be a good resource to learn about it myself, and potentially write my own?
An explanation of the Native API? What does it do? Can I use it to make applications better? Can I even USE it at all?
An answer to any of those is highly appreciated :) thanks
You could start at PInvoke.NET.
The LayeredWindows actually work better in WinForms than windows.
The native windows controls don't even have the alpha channel support of the WinForms analogues, so native windows flicker, and require massive amounts of subclassing to override the painting to use alpha compatible routines.
You would be better off going to WPF. The windows team has not treated the native control's well at all, going so far as to remove support for a style (WS_EX_COMPOSITED) if aero glass is enabled which, given the way that windows controls paint, effectivly made it impossible for any application to paint flicker free if it uses child window's as controls.
WPF "draws" windows controls, but does not use discrete (native) child windows to represent individual controls. This gives it control over when and how its window surface is rendered.
The Windows API is huge. There is a ton of stuff in it. Windows Forms is a wrapper of parts of it. WPF is a wrapper of parts of it. Parts of the Base Class Libraries (eg System.IO.*) are wrappers of parts of it. The Code Pack is a wrapper specifically of things that were new in Vista and Windows 7 and not in Windows Forms or WPF.
Have you looked into WPF? Combined with P/Invoke of specific API functions, it might take you a long way towards where you want to be.