Is there a way to do 'real time' streaming with asf?   

I'm trying to build a system that can 'remote' an application by streaming it 
to another machine with minimal lag.  I am current capturing screengrabs of 
the app and placing them into an .asf file set to 30fps and then serving that 
via a network port.

The problem I'm hitting is that the 'client' that connects (currently wmp, 
but eventually will be a wmp hosted in media center) buffers the video.  This 
causes a 3 to 5 second delay in what I'm doing to the apps responsiveness.

Is there a way, via API, client setting, reghack, codec, anything...to 
shrink this buffering?  I'd be willing to drop frames, garble, or take a hit 
in most other areas if I can not have it buffer.  

If .asf is nto capable of this, is there another route that could be 
suggested?  My primary client to get this working on is win7, with Vista as a 
secondary option.

Thanks in advance for any help you can offer

date: Sat, 27 Jun 2009 02:13:01 -0700   author:   JFarro

Re: Is there a way to do 'real time' streaming with asf?   

From: "JFarro"

> The problem I'm hitting is that the 'client' that
> connects (currently wmp, but eventually will be a wmp
> hosted in media center) buffers the video.  This causes a
> 3 to 5 second delay in what I'm doing to the apps
> responsiveness.
[...]
> If .asf is nto capable of this, is there another route
> that could be suggested?  My primary client to get this
> working on is win7, with Vista as a secondary option.

ASF has nothing to do with the streaming delay since it is
just a transport stream. The delay comes from a number of
sources: the network buffer on the player and the encoding
buffers on the encoder are the most important ones. 3-5 secs
are as low as you can get.

Neither the WMV nor the WMA codecs are designed for
low-delay streaming. Most modern codecs are designed for
high quality, not low delay. If you need low delay, you need
to use codecs designed for that, like codecs designed for
telecom applications.

Are you using WME9 or the WMWriter directly? By doing a lot
more work, you can reduce the encoding delay (e.g. see the 
source for
ConferenceXP on research.microsoft.com), but you can not 
reduce WMP's network buffering time (however you can replace 
WMP's receiver with your own).


-- 
// Alessandro Angeli
// MVP :: DirectShow / MediaFoundation
// mvpnews at riseoftheants dot com
// http://www.riseoftheants.com/mmx/faq.htm

date: Sat, 27 Jun 2009 12:12:04 +0200   author:   Alessandro Angeli