I am making a C# app to capture graphic from an avermedia pcie capture card.
But it seems that there are no out of box tools to do so.
So I made a C++ directshow app to do the capture, which is a console app and opens a capture window when running.
How can I redirect the output to a C# app? for example, to a CaptureElement?
So you want to have XAML CaptureElement connected to AverMedia PCIe capture card. This sounds like a well-understood challenge overall, however every other piece of technology you mentioned is eventually a bad choice: DirectShow, multiple apps with piping, redirection and fitting of cutsom code to XAML CaptureElement control.
Microsoft has intentionally been limited ways you can integrate different APIs and so there are not so many ways to get everything together.
Let us go over the supposed integration path. The capture card is supposed to be shipped with a compatible driver:
Video capture devices are supported through the UVC class driver and must be compatible with UVC 1.1
When this is the case, such devices are visible to Media Foundation API handling video capture among tasks. XAML CaptureElement would be able to see a video capture device through this API and this way everything is supposed to work without need to fit anything from your end.
If this is not happening, it suggests you are dealing with an unsupported device coming without suitable or compatible driver.
Previous media API in Windows was DirectShow but its days are gone. It remains perfectly working as a legacy framework, a lot of applications out there are still relying on it. Specifically it will not integrate with new technology like XAML and UWP. More to that, even Media Foundation itself, the current media API, in its public offering is lagging behind when it comes to fitting with most recent technology. Having said that it is a good idea to stay well clear of DirectShow here if this is at all possible.
I see no need for cross-process design with video travelling between process through piping. There is no good reason for such design and even though this can work efficiently (Windows itself proves it can work great in terms of performance by having so called Frame Server service in it), this is not to be built on piping. In your case it is unlikely to be have to be built on multiple processes either. Instead you can develop a native code DLL project that takes care of video acquisition and connects to managed code via suitable glue layer: C++/CLI, COM, C++/WinRT and such.
Then next thing is fitting to XAML CaptureElement. The control is designed to work with Windows.Media.Capture.MediaCapture class that talks to hardware and you don't have suitable hardware as you plan to implement your own acquisition layer. Long story short you are not supposed to forward external data to CaptureElement and you would have hard time doing this. Your best strategy is to upload externally obtained data to Windows.Graphics.Imaging.SoftwareBitmap or alike and take involved performance impact as acceptable. That is, you will be dealing with video frames as images.
An alternative way is to upload acquired video frames into Direct 3D 11 textures and it would open you a more performant way of integration with video related controls, such as Windows.UI.Xaml.Controls.SwapChainPanel however it would also require that you put much more development effort in there.
I need to be able to record video from an external camera in a C# application.
Unfortunately a webcam is pretty much out of the question as the application will record outside and during the evening/night. That is why I was thinking of a camcorder since it also has manual control over exposure and focus, lower noise and better sensor.
So far I would use the AV/S-Video output from the camcorder and send the signal to a USB capture card (the computer is a laptop so no PCI-E cards).
How would I be able to access the video stream from the C# application, now that it comes from the capture card ?
Does my proposed system seem feasible (achievable, good video quality, good fps)? Does anybody have another working solution?
Thanks
This Code Project Article could be of a good starting point.
The Author mentions :
The main goal of the application was to make it flexible and
extensible. The application itself can communicate with any video
source – it may be an IP video camera or a server, it may be a local
camera attached to USB, it may be an MMS stream from a remote server,
or it may be any other video source. And more of it, the application
can work with all these video sources simultaneously, displaying them
all on a single screen.
The solution I used in the end was Microsoft Expression Encoder.
I'm trying to create a background application that allows me to easily change volumes of the rear channels
I've looked into the Core Audio API, and although I managed to change the balance/volume of the front speakers, the API seemingly had no access to the rear channels or any other surround channel. It only counted 2 channels for my audio device.
Is it in any way possible, using any API, to control the rear channel's volume?
Thanks in advance!
EDIT
Thanks, FMOD looks like what I need, although it's a bit overwhelming. :P What would I need to do, to change the volume of a specified channel. I believe I need this function:
FMOD.RESULT result = channel.setVolume(1.0f);
But then I need to find a way to specify the channel...
Also, to be clear: I need to change the volume of any running application, say Winamp.
Best chose for working with audio file is "Fmod.dll".this have a lot of Privilege to work with audio file.
This is an audio content creation tool for games, with a focus on a
‘Pro Audio’ approach. It has an entirely new interface that will be
more familiar to those using professional Digital Audio Workstations
than existing game audio tools and is loaded with new features.
I already use this,this is very powerful component and easy to use.
I want to make a similar application to Skype, and the main problem is working with video and audio. The first problem is how to get a bytes array of the video (to be specific, I need to get bytes which represent the video, so that I can send them over the internet), and same with audio. The second problem is to play bytes that come from the other computer.
I've been thinking to do that in WPF. I'm new in WPF (I have practiced a little bit, and made couple of programs among which is a basic chat program). I'm doing this for practice, and I want to code by myself as much as I can, server, client, transmision of data, and so on...
I've been searching over the internet, and only one solution seems to me to be good, or better to say feasible, is to use DirectShow.
Just to add, I know that camera and microphone is supported in Silverlight, and I've tried that (actually, I've tried to host an HTML page with silverlight project in WPF project in which were webbrowser control, and I've succeeded to show video from my webcam), but I don't know how to get bytes which represent video.
Is that possible to do with WPF or silverlight?
I'll be very grateful for suggesting any solution, advice, or useful links.
Using DirectShow filter graphs, you'll have a direct access to image and audio buffers from input devices (such as cameras and microphones) as bytes array, sample by sample. You'll be able to directly manipulate the data, to chose a coding or compression format (using specific filters), and to control the data rate and synchronization.
However :
if you've entirely new to this environment, it will be hard. Also, I know it works nicely with C++, but I've never coded any Directshow application in C#. (You may want to look this way : CodeProject Tutorials, MSDN DirectShow topics, and tests using graphedit)
streaming media accross a network and receiving it with Directshow is not trivial and can be quite a pain. Network renderers and network source filters are available all around, but are always difficult to use in my opinion. And depending on your video format (H264, MPEG, MJPEG...) and network protocol (RTSP, plain old simple UDP...) choices, you might end up having to write your own stream/source filters, which is hard and time consuming.
Nevertheless, it IS feasible, and if your main objective is practice with coding, then why not !
(Never used WPF, maybe it's actually way simpler !)
I can't speak to WPF or Silverlight, but I've done this in DirectShow, and it's a pain in the ass.
If you want to use .NET, there's an open source wrapper called DirectShow.NET, that helps alot, and it's still a pain in the ass.
Microsoft did a good job with DirectShow and the whole Filter-Graph thing, but then they sort of dropped the ball a while ago and haven't updated it in years.
I'd recommend looking for a different technology(although it probably sits on DirectShow), and I'd be interested to hear what you find.
To all who are interested in this subject,
After spending hours and hours searching the internet, i managed to find a solution that should work. With Silverlight i take captures, resizing them to 160x120 (or less), and than convert them with imagetools. One thread that is responsible for taking pictures, starts capture, and when it is finished (capturing is asynchronous, so you need semaphores to use) it sleeps for 200ms; thats almost equivalent to 5 frames per second. I'm doing all of this because i have slow upload bandwidth, about 16 kilobytes per second, so i have to compress one frame as much as i can. Result is low detailed picture, but if u use 100x100 rectangle for viewing it, it isn't too bad. I haven't tried it with the internet yet, but, as i have said, it should work. I've also tried using compress methods, to compress picture a little more, if it is possible, but i don't know how to use that class (something is not working well), so left that for another time. Now i just want to make it work, and latter i'll try to make better performance.
Oh, one more thing, I also have to solve problem with audio transmission, and that needs a lot of work.
So, hear latter.
I'm looking at trying to create a simple 'slider puzzle' game. You've seen the ones, you have an image and you shuffle the tiles.
However, I want to make one that will play back videos instead. What I'm trying to determine is whether it's possible to playback a video in C# and render the video on different controls (probably buttons, or panels). I've spotted the Microsoft.DirectX.AudioVideoPlayback classes but haven't found much documentation on them yet.
So to throw it up in the air, is this going to be possible to do without too much difficulty? Are there any useful (free) libraries that might help me along?
Have a look at DirectShowNet that wraps the DirectShow API, in the samples page there is a sample called PlayWnd the shows how to play a video file.
Depending upon how large and how long your video sources are, you could accomplish this very simply by first converting your videos to animated GIFs. A .Net PictureBox control will display and animate a GIF automatically, and you could easily use PictureBoxes for your tiles.
One big advantage of this approach is that (thanks to Mono) your application could work unaltered on Windows, Mac and the iPhone (also Linux and a couple others).