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Home Forums General Silverlight Hosting and Streaming Why not _real_ streaming on "Silverlight Streaming" (silverlight.live.com)?
9 replies. Latest Post by Alex Crieg on April 2, 2008.
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Alex Crieg
Member
61 points
35 Posts
03-28-2008 3:04 PM |
So, it is well established that the "Silverlight Streaming" site is not really using true streaming, but merely progressive download. See for example, this somewhat dated post: http://www.onflex.org/ted/2007/09/windows-live-streaming-not-really.php
My question is, since MS owns "silverlight.live.com" and also owns Windows Media Services 2008 (which can do real streaming), why don't you just use WMS on your silverlight.live.com servers and offer real streaming? Or is that planned? Or does true streaming demand a lot more hardware? Is getting that beefier hardware that a big deal? Presumably the live feeds in the Olympics project are going to be fed with WMS on a massive scale?
Thanks,Alex
nesnyc718
17 points
8 Posts
03-29-2008 7:47 AM |
Umm.... I think that article is wrong. WMS can do http also; if you're limiting yourself to mms, rstp or udp then you'll shut out a large segment of your audience that has those ports blocked. I'd say 50% of users have those port blocked, especially corporate firewalls.
Using WMS in http and port 80 can give you archives AND live events all seamlessly. You may call it "progressive download" but the WMS is relaying the packets in real time.
03-29-2008 9:47 AM |
> Umm.... I think that article is wrong. WMS can do http> also; if you're limiting yourself to mms, rstp or udp> then you'll shut out a large segment of your audience> that has those ports blocked. I'd say 50% of users> have those port blocked, especially corporate> firewalls.
Sounds like a reasonable argument. Can someone from MS comment on that? Frogs69? I uploaded a trial video to the SLS site. When I browse to that page I can move the slider to the middle of the video, but I don't actually get to see that part of the file until the progressive download has slowly downloaded the entire first half of the file. The SL player colors the slider darker for the portion that has been downloaded already. You can watch it slowly progress across the full width of the slider. Only when all the file has downloaded can I seek anywhere in the file relatively quickly.
This previous commenter points out the same thing:http://silverlight.net/forums/p/11892/38612.aspx#38612
This is the site of a 3rd party host that provides _true_ streaming. They go into detail about the "seeking" advantages of true streaming:http://streamhoster.com/streaming_services.html
Alex
03-29-2008 3:36 PM |
Alex Crieg:I uploaded a trial video to the SLS site. When I browse to that page I can move the slider to the middle of the video, but I don't actually get to see that part of the file until the progressive download has slowly downloaded the entire first half of the file.
Do you know for a fact the SLS site is a WMS? Sounds like a standard web server you're uploading to. If this was a windows media server and had it's http protocol enabled, you could call the file like this: mms://mywms.com/mypubpnt/mymedia.wmv and you would end up getting an http connection if the other protocols failed to connect.
03-29-2008 5:32 PM |
Okay, I think I have the answer to your questions, see this post:
http://silverlight.net/forums/t/586.aspx
03-29-2008 6:42 PM |
>Do you know for a fact the SLS site is a WMS?Actually, I'm assuming it is not, and I'm asking why not? (Maybe firewall issues?). I would like the seek-anywhere-fast ability that WMS's true streaming would apparently give.
Two more tests:If I upload a video to SLS and then browse to the test page while watching the HTTP traffic with Fiddler I see the ultimate URI of the WMV file. For example: http://msbluelight-0.agappdom.net/xxxxxx/video.wmv If I paste that URI into IE, it opens Windows Media Player and I get the same progressive-download (PD) behavior. That is, I can't seek ahead in the file. If I change the http to mms I get exactly the same PD behavior. This implies SLS is not currently WMS.
OTOH, if I go to the MIX08 video site (http://sessions.visitmix.com/) and watch one of the videos from the integrated SL player while watching the HTTP traffic with Fiddler, I again find a path to a WMV file. For example: mms://msstudios.wmod.llnwd.net/yyyyyyyyy/DEV13.wmv When I paste that into IE, again Windows Media Player is openned. But now (unlike SLS) I get true fast-seeking ability to anywhere in the file, without having to wait for it all to download first. This is regardless of whether I use mms or http as the scheme. Therefore, the MIX08 video site seems to be using the real WMS with real streaming. Oooo. Me want .
So my question is, why doesn't SLS give me that kind of seek-anywhere-immediately behavior? As it stands now, the current SLS should probably be re-branded as SLPD (Silverlight Progressive Download), so as to not falsely raise people's expectations. Or maybe create a new additional service called "honest-to-goodness-SLS", that really does true streaming, for folks like me who want that.
03-29-2008 7:03 PM |
Alex Crieg:Actually, I'm assuming it is not, and I'm asking why not? (Maybe firewall issues?). I would like the seek-anywhere-fast ability that WMS's true streaming would apparently give.
I run a WMS and I cann tell you that it's quite hard to manage user accounts and uploading content. Not sure why they are saying it's a streaming server but maybe it is and you're not calling it the right way.
Alex Crieg:For example: http://msbluelight-0.agappdom.net/xxxxxx/video.wmv If I paste that URI into IE, it opens Windows Media Player and I get the same progressive-download (PD) behavior.
did you try to open it with mms:// in WindowMedia player? That would be the definitive test to see it's that's a media server or plain http.
Alex Crieg:As it stands now, the current SLS should probably be re-branded as SLPD (Silverlight Progressive Download), so as to not falsely raise people's expectations. Or maybe create a new additional service called "honest-to-goodness-SLS", that really does true streaming, for folks like me who want that.
Well, are you paying for that service? If so, you should be concerned about "false" adveratising. Otherwise, I have a publishing point to sell you via a true WMS streaming service.
03-29-2008 9:27 PM |
nesNYC718: did you try to open it with mms:// in WindowMedia player? That would be the definitive test to see it's that's a media server or plain http.
I did the test again directly in Windows Media Player both with mms:// and http:// and I get the same progressive-download, no-seeking-until-it-is-all-downloaded behavior. Therefore SLS must be plain HTTP.
Frogs69
Participant
798 points
219 Posts
04-02-2008 1:28 AM |
Hi folks, as I wrote on my reply to the onflex blog post, SLS is indeed on-demand http progressive download. I won't rehash it all in this thread, but the terminology set aside (and yes, I agree it is a bit of a misnomer misnomer when referring to video) we've made no seceret of the technology used under the hood for the SLS service. We are using web servers for the API, origin and invocation services, and SQL servers for the accounts database. There is an architecture overview of the service in the SDK, and in the MIX deck that I presented a few weeks ago.
Using media servers to provide "true" streaming via a CDN (Content Delivery Network) is possible. We've looked into it and it is supported by the CDN infrastructure. We'd "only" have to setup the media servers in the back end. But there are many other things to do too. There are various reasons why progressive download was picked over true streaming, and technology changes are more and more blurring the lines between the two, in the vast majority of scenarios. I'll post a more comprehensive article about this on the service blog soon enough, as it keeps coming back.
Silverlight 2 now supports byte range requests, so we should be able to make the service support that functionality to enable forward seeking, speed up the playback experience and minimize the download requirements on the client side.
Cheers.
04-02-2008 12:18 PM |
Hi Frogs69,
Thanks for responding.
>I'll post a more comprehensive article about this on the service >blog soon enough, as it keeps coming back.
It "keeps coming back" because the overall "Streaming" brand screams one thing, but the fine print reveals another thing. It doesn't really help to in-effect argue: "well we tell you in the fine print it isn't real streaming" or "well it is widely known already that it isn't real streaming". The let-down is the same. I personally didn't even know what "streaming" was until a few weeks ago. It was the fact that MS had this apparently wonderful "Silverlight Streaming" service that caused me to look into what "streaming" actually meant. If it had just been branded with something like "Silverlight Video-On-Demand", it might not have crossed my mind .
Regarding how important "true" streaming (as used on the MIX08 site) really is. Granted maybe only a few people do really want it.
IMO, when picking a brand-name, it is best to emphasize some advantage you really do offer. For example, in your reply to Ted's blog post you say "...Microsoft tells a good story because it is a good story. ... It’s a free global service that offers more than twice the bandwidth of any other free video service on the web...". Assuming that is really true, and assuming you are really commited to maintaining that advantage longer term, then you could realistically brand it something like "Silverlight Fat-Pipe Video" or something.
>I'll post a more comprehensive article about this
That would be great. Another article I'd like to read (although I imagine it's a different group) is the background behind the web-casting infrastructure to support the Olympics site this summer (including technical details).
Why not _real_ streaming on "Silverlight Streaming" (silverlight.live.com)?