Re: Video Conferenceing Queries

I have to make a Video Conferencing module for one of our ASP.NET Intranet site where a user can actually choose from the list of available Cameras and can view or record (and rewind,pause, play or ff)  and save it in a file. The same cameras can be seen by different users so it is kind of Server to Many Conxns Scenario. I am a beginner in Leadtools SDK and was looking for a solution for the problem.

From last couple of days i have been playing around with the  Player Control and Capture Control, till now I have been successful in playing the web stream (and controlling play, pause, stop fnxns) from server which can be seen by a client on a web page. My problem is how to capture/record that direct video stream at client side. I am not getting any way out in Capture Control. How can I assign the stream being displayed in Play Control to Capture Control and save it in a particular format (either using Convert Control) or without any format.

Please guide me or gimme some coordinates about good examples or documentation regarding video conferencing.

Also, as I am working on web pages, I am using Javascript to handle ActiveX Objects exposed by LeadTools Multimedia. Is there a better method to use it?

Thanks,

Ashish

If you want to change the text on each frame, you need to use our Video Callback Filter. This filter will give you a callback event for each frame. Every time you get a new frame in, you can change the text in the text Overlay Filter.

The file size is purely dependent on the format and compression you use. If you want the file size to be smaller, you need to compress the file more. If you are using the Convert control to save the file, you can choose which format and compressor you want to use.

All of the filters and codecs are fully documented in the "Multimedia Filters Helpfile" (Ltfilters.chm). This help file is installed with the SDK.

If you are trying to save the file you are streaming on the server side, you need to use a Convert control on the server side and have it basically connect to itself so that you can record it. Alternatively, the Network Demultiplexor has a property called "OutPutFileName". If you set a path to this property, it will write the stream that the client (player control) is receiving to disk. The only drawback to this is that you will need the Network Demultiplexor to play the file. If you used the Convert control, you would not.

Hi,

Thanks for responding..

I am having couple of problems with Motion Detection Filter, Video Callback and Overlay Text Filter. I need to use these filters on Convert Control.

As i wanted to put timestamp on each frame, I used Overlay Text filter but doing so, makes the frames to run faster than the normal speed though i haven't set or specified any property value. Also I am still stucked to the static TimeStamp which means its not able to change on consecutive frames. I know that I have to use some callback mechanism to put current time on each frame manually but there seems to be no Callback Object for that filter.

Then, I saw the Video Callback Filter Example which is having PlayCtrl instead of Convert Ctrl. I extended that example by putting current time on each frame manually with using Windows APIs like TextOut etc. and was successful in doing so. But it does not seem to work with Convert Control.  The activeX Control which i made is a combination of Play Control and Convert Control. I am setting the value of sourcefile of Play Ctrl by putting ltsf://ipaddress:port (Capture Application is running @ server side which is sending stream) and using convert ctrl i save the file whenever User clicks Record button. All this works fine except this Video Callback Filter.. I tried to put callback video filter on Convert Control in my activex Control and it does not work at all and Here is the code snippet:

For idx = 0 To Convert.VideoProcessors.Count - 1
    If (Convert.VideoProcessors.Item(idx).FriendlyName = "LEAD Video Callback Filter") Then
        Exit For
    End If
Next

Convert.SelectedVideoProcessors.Add Convert.VideoProcessors.Item(idx), 0

Set lmvCallback = Convert.GetSubObject(ltmmConvert_Object_SelVideoProcessor)
If Not lmvCallback Is Nothing Then
    lmvCallback.ReceiveProcObj = lmvMyCallBk  
End If
 Set lmvMyCallBk.LeadDlg = LRasterClrDlg

The callback (lmvCallback.ReceiveProcObj = lmvMyCallBk) never works although it worked in a case of Play Control when i was using it with a saved file instead of stream. The source file of Play and convert is same (ltsf://...).

I have attached an example that uses the convert control to draw a different number on each frame of the video. This project uses LEADTOOLS Raster Imaging Pro (COM objects) to draw on the bitmap but you can use Windows API calls as well. If I understand your objective correctly, this does exactly what you are trying to do.

You can use as many filters as you like at one time. You just have to make sure you keep up with the index of each filter. Take the code below for instance. Once Filter1 has been added, you call GetSubObject to retrieve the actual object from the graph. The constant 'ltmmConvert_Object_SelVideoProcessor' actually has a value of 512. Each filter you add will have a different index so you need to increment this value as well. So if you add a second filter, it would be 'ltmmConvert_Object_SelVideoProcessor + 1'. You can also use a value of -1 instead of hard coding the index. This will add it to the end of the list for you.

Convert.SelectedVideoProcessors.Add Convert.VideoProcessors.Item(idx), 0

Set Filter1 = Convert.GetSubObject(ltmmConvert_Object_SelVideoProcessor)

Convert.SelectedVideoProcessors.Add Convert.VideoProcessors.Item(idx), 1

Set Filter2 = Convert.GetSubObject(ltmmConvert_Object_SelVideoProcessor + 1)

File Attachment(s):

COM - V14 - CallBackFilter convert file and write number on frame.zip (4kb) downloaded 48 time(s).