If you don’t know what ads/comments you will need to insert ahead of time, then insert markers which correspond to some lookup scheme (e.g. DoubleClick calls).

Thanks for your answer.
I got the method you were explaining but in my scenario, if I don’t know what announcements/ads to place in advance and also what position (e.g. I need to put markers for user comments in text stream which are stored in a db) what should I do?

I basically need a way in which everytime user starts a video I should be able to create text-stream dynamically. At the same time I dont want to generate the entire ismc file at runtime.

Please help.

I recommend you look at http://www.codeplex.com/Wikipage?ProjectName=smf because the Silverlight Media Framework is already enabled for interpreting ad insert metadata.

If you’d like to insert ad markers into pre-encoded content, you could do it by appending ad stream metadata to the client manifest (*.ismc), like this:

The string within the F tags is just a base64 encoded string formatted in a way that makes sense to your client.

Byte range requests weren’t used because:
1) they’re not universally cacheable
2) at the time of Silverlight 2 (when Smooth Streaming was being developed) not all browser stacks supported HTTP 1.1 yet

GET /blah HTTP/1.1
Range: bytes=0-999
…
HTTP/1.0 206 Partial Content
Content-Length: 1000
Content-Range: bytes 0-999/10000
…

This is what the iPhone/iPod Touch does: no special software required on the server – it’s plain old HTTP 1.1.

Can you point me to some resource on how live ad insertion is done or for that matter how to provide text streams dynamically.
The scenario is I have a pre-encoded smooth streaming content and need to append metadata dynamically. e.g. Announcements etc., without having to encode the content again.

Thanks in advance.
- Sushil