Video streaming!!!

ok.. i have to clarify this. i'm sorry it wasn't clear earlier.

first of all, i have to write code. not writing code is not an option.. i'm an intern!

secondly, i can use sdks if i want... or any libraries, but i have to actually write the code because there are several other requirements that make this project unique. they will not be too hard to implement once i can get the streaming stuff going, but i have to be able to do that.

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I'm not sure I'm too clear on this. Do you want to write code to forward the video traffic from your web cam, or write a video viewing application, or both?

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both. i'm building a client server model (actually there are two types of clients: 1. computers with webcams attached- there can be several of these. 2. actual client who wants to view the webcam from a remote location). the camera client sends the stream to the server, the server to the actual client. the actual client must be able to view the stream- and therefore, i have to create a video viewing application as well. eventually, i have to support wireless webcams as well- but that is later once i get teh wired (USB) ones going.

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All you need to do is map the port from you web cam through your firewall/router so that it is visible externally.

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that sounds ok to me.. but i'm not sure if any data is sent to teh webcam from teh driver or computer or anything.. if i were to do this, would i be responsible to respond to teh webcam? i dont' even know for sure that any data is sent to the webcam. but if it is, this might be an issue? just a thought.. but not sure. also, i don't really know how to go about doing this. do you know of any links or something where i can read up on it? would really help me out!

Edit: actually, for the above quote, if i am doing something like that, i would rather grab the info and send it through a socket.. do you think that is workable too? and if so, hwo do i go about grabbing the info?

i hope that clarifies things. if you have any further questions, please let me know. all suggestions still welcome!

thanks for all the help so far guys! keep those suggestions coming! i really appreciate them!

Hi drewdaman,

As I can speak as someone who hasn't been using dshow for too long, take heart! You do not need to know all of COM in order to program dshow. A definite subset of concepts is necessary, but the nuts and bolts aren't particularly needed. First of all, you won't need to use any idl. If you are comfortable instantiating objects and querying interfaces, that will get you a good bit of the way. Please note that I haven't actually send video over the network, so I'm hypothesizing a bit.

I'll take this slowly and build it up a bit. Please don't think I'm patronizing.

All of directshow uses graphs to string together and connect various components called filters. A typical filter will consist of a source filter, several intermediate filters to get the video into a stream of bitmaps, and finally a renderer. The renderer is what you see in the window that plays the video. The graph is kind of the overseer of all of the components. Through methods called on the graph, you can stop, pause, play, get notifications, etc. This compartmentalization is very useful, as MSoft provides many filters that are very useful. Graphedit is a harness that simulates a graph you would build programatically. It is a very useful tool, but unfortunately not a means to an end. The bottom line is that if you cannot get it to work in graphedit, it won't work at all!

So, now I have good news and bad news for you. Windows media appartently has filters that work over the internet through directshow. The bad new is that I have no knowledge of them, so I can't help you! The application to view the video is almost trivial to write, so don't worry as much about that. Getting data over the network will be the hard part. I have to get going, but I'll update this with some more thought when I have time. Good luck.

~Steve

i m working on a project which needs to stream video from a webcam or file to a remote location.. 1 way broadcast is needed. i hv gone through the options like Windows Media Encoder and DirectShow. However, I couldn't find a way to implement direct video streaming to a server n then clients will b able to receive the streams immediately.
how m i go about developing it?
fyi, i m a college student. i did some research n i still couldn't find an appropriate to do it. Dealing with COM is pretty complicated coz I need to develop it under C#
thanks...

Hi,

Sorry, AFAIK there is no way to use directshow in C#. There is no indication that a managed interface is coming either. There is some info on how to use VB, but that's it. You might want to check out the code of videolan, I'm not sure how that works.

~Steve

Actually you CAN use direct show from C#. I know, I've just written an assembly which'll give you full access to the underlying interfaces etc.

I've had to do some pretty heavy interop to do it though, so it's not for the faint hearted.

I could potentially write something so you could write filters in C# but that's WAY too much like hard work. The C++ base classes in the DirectShow examples are ok at doing much of the hard graft for you, so I've not bothered.

Unfortunately no I can't release the source code for it because it's part of a commercial project. But just to let you know it IS possible.

As an aside, if you pipe the output from the encoder into Media Server then you can multicast the output. In fact from what I've read it's not difficult : the whole UI is set up to help you do just this.

No coding involved though... if you're looking at writing all of this yourself then you're looking at having expert knowledge of

(1) COM (to use DirectShow to do the capture. You could always use the old way of course using VFW - video for windows - but I don't know much about that).
(2) COM again to write an addin for Internet Explorer to connect to your media server (which you'll have to write of course) and buffer/stream the video/audio.
(3) Networking. You'll have to work out an efficient way of transferring the images.

To write all of the above yourself is an INCREDIBLY challenging problem and one which you'll have to be working on until 2am for the whole year to get anywhere close.

It's unlikely you'll be able to do it purely in C#. My DirectShow interface has grown out of years of knowledge and experience with DirectShow and COM.

If you're going to get anywhere close to acheiving your goal you will have to learn C++/MFC.

Darwen.

Maybe avphone is fit for you:
http://www.banasoft.net/AVPhone.htm