CODEWITHSUNDEEP
c#wpfsilverlightstreamingdirectshow
miki
miki

Reputation: 381

video call in c#

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.

Upvotes: 3

Views: 5517

Answers (3)

miki
miki

Reputation: 381

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.

Upvotes: 0

fulguroblastor
fulguroblastor

Reputation: 606

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 !)

Upvotes: 1

LoveMeSomeCode
LoveMeSomeCode

Reputation: 3947

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.

Upvotes: 1

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