Michael Creasy's blog : Media Center

Many questions - MSAS, playing WAV files and what to develop Media Center apps with

mcreasy — Thu, 14 Jul 2005 02:28:00 GMT

I've had lots of questions recently and no time to really get answers and post them up here. If I haven't answered you question it's because I don't know the answer and haven't had enough time to get to the bottom of it yet.

First of all I had a couple of questions on MSAS which I don't know that much about.

Can I tell which tuner is being used when a recording takes place using MSAS? No, you can not. What you can do, which may or may not help is use OnTVRecordStateChange from a background add-in which will give you a GUID and you could track which was in use - this won't help if a tuner is being used for live TV though. Here's a code snippet on how to use OnTVRecordStateChange:

void IAddInEntryPoint.Launch(AddInHost host)
{

host.Television.OnTVRecordStateChange += new Microsoft.MediaCenter.AddIn.TVRecordStateChangeDelegate(TvRecordStateChangedHandler);

...

}

public void TvRecordStateChangedHandler(object obj, Microsoft.MediaCenter.AddIn.TVRecordStateChangeArgs TVArgs) {
if (TVArgs.Started)
mcHost.HostControl.Dialog("Recording started on tuner " + TVArgs.Tuner, "TV Recording",1,10,false);
else if (TVArgs.Stopped)
mcHost.HostControl.Dialog("Recording stopped on tuner " + TVArgs.Tuner, "TV Recording",1,10,false);

}

Can I use remote desktop to connect to a Media Center PC? Yes. You can even use Media Center, but it won't play video over a RDP connection

Can I use animated backgrounds in an HTML page? Not really a media center question, but I don't see why not, use an animated gif.

Could I create an add-in that played a selection of WAV files with a gap between them? Yes, using Playmedia and Playrate you could contstruct an addin to do this - waiting until the playrate was stopped, then wating however long you want before playing the next file. You could also use More With This to make this work with any folder of audio files.

Can I use ASP.NET for development? Yes. You can use any web technology that outputs HTML.

Can I use WinForms for development? Yes, but if you're running as a .exe you won't have access to Media Center APIs. If you're running as a .NET applet in a webpage you'll have access to the Media Center APIs from the HTML page and will have to communicate between the page and the .NET applet to use the Media Center APIs - non-trivial to do, but not hard.

This week's questions (actually last week's): More on HTML and add-ins

mcreasy — Sat, 25 Jun 2005 02:18:00 GMT

How are HTML apps and add-ins associated with each other? (Can HTML apps trigger add-ins to be launched?) HTML and add-ins can both be part of the same application, that is each is a different entrypoint of the application. The association takes place at registration time, when both would be registered as one application. An HTML page can start an add-in (on-demand only, not background) by using the NavigateToPage function with the guid for ExtensibilityEntryPoint as the first parameter.

Is there a way for HTML apps and add-ins to exchange information (parameters) and trigger events? (Is it possible for an add-in to be registered as a listener to an event that is fired within an HTML application?) No, there’s no built in way for add-ins and HTML pages to communicate.< Communication between a background add-in and an HTML page could be achieved with an ActiveX/.NET control on the HTML page and then .NET Remoting between the two components.

How do I register a .exe file so it runs from More Programs? The same way you register an add-in, except instead of using the “addin” property on the entrypoint tag, use “run” with the path to the .exe

Media Center PC's are getting cheap!

mcreasy — Fri, 24 Jun 2005 05:45:00 GMT

Betanews reports that Gateway/eMachines will be offering a new Media Center PC for $599! The specs are pretty impressive for such a cheap computer:

AMD Athlon 64 3400+
1GB DDR SDRAM
200GB hard drive
ATI Radeon Xpress 200
8 in 1 media reader
Rewritable dual-layer DVD drive
CD-ROM drive

Wow. No mention of a TV Tuner, monitor or remote though...

I've never bought an eMachines computer before, but that seems like a great deal for a pretty powerful system.

This weeks questions - always on top and registering add-ins and HTML together

mcreasy — Sat, 11 Jun 2005 02:22:00 GMT

I've decided to take all the questions I get by email and answer them on Fridays in one post, so do please continue to email me any questions you have. That said, here's this weeks questions:

How can I keep the Media Center window on top so I can work on other things? In Media Center go to Settings\General\Startup and Window Behavior and select "Media Center window always on top".

How can I associate an HTML application with an add-in? Register both the add-in and the HTML page together. Instead of registering the HTML app and the add-in you need to register them both as a single application with multiple entrypoints - one entrypoint for the add-in and one for the HTML page. This will make them both part of the same application and so from a background add-in a call to ApplicationInfo.IsForeground will return "true" when the HTML page is currently being displayed.

How to disable a Media Center add-in

mcreasy — Fri, 10 Jun 2005 03:06:00 GMT

Jason over at Digital Media Thoughts sent me an email about his new article on The Powers and Perils of a Platform. Jason talks about the trouble he had when a Media Center "plugin" went bad and couldn't be uninstalled. It's not clear if it was an HTML application or a managed code add-in, but based on the description I'm assuming it's the latter. He ran into problems when trying to manually uninstall the application so I thought I should post something on what to do when an add-in goes bad...

In Media Center 2005 add-ins can do pretty much what they want to do without restriction, if one starts to misbehave the best thing you can do is to disable it:

Start Media Center
Click on Settings
Click on General
Click More Programs Options
Click Edit More Programs
Deslect the app to disable and click Save

This will disable the app from starting and hide anything entrypoint it's registered throughout Media Center. It won't uninstall the app, but it will prevent it from running.

Questions answered

mcreasy — Sat, 04 Jun 2005 02:56:00 GMT

I've had a couple of questions by email that I should answer (note I've paraphrased some of these):

What fonts should I use for my HTML Media Center application and can I use Flash? The SDK is where to go for design guidelines for HTML applications (the short answer is to use a sans serif font). Yes, Flash can be used in HTML Media Center applications - Napster and MSN Music both use Flash.

How can I add an application to the Start Menu? You can't. Well OK, you can, but we recommend that only OEMs use this functionality as there is a limit to how many applications can appear on the start menu and adding a new app will stomp on existing applications. If you intend to distribute your application you shouldn't do this, but if you really want to know, the details are in the SDK here.

I've seen the Media Center software for sale online is it OK to buy it? I'm no lawyer so I'm not going to comment on this. Media Center is an OEM product and only available with new PCs is the official answer though.

Media Center keyboard shortcuts

mcreasy — Wed, 30 Mar 2005 22:29:00 GMT

All the keyboard shortcuts for Media Center for those times when you just don't want to use a remote control are documented here.

Update: If the page doesn't display, try again later, it's propagating around servers or something like that I'm told

MSN Remote Record

mcreasy — Thu, 24 Feb 2005 17:34:00 GMT

MSN Remote Record is live and out of beta. In simplest terms it's a way of browsing the same TV guide as your Media Center PC uses and then remotely instructing your Media Center PC to record something. Pretty clever stuff. There's a small download for your Media Center PC and then it looks pretty easy to use.

Try it and let me know what you think.

Emailing me with tech support requests

mcreasy — Wed, 23 Feb 2005 18:01:00 GMT

I get a lot of emails asking for help with people's Media Center and I can't answer them all. Feel free to email me with things you'd like me to write about, but please understand I can't answer all the emails or provide tech support for you. If you have a problem I encourage you to use the newsgroups where you'll likely get your question answered, possibly even by me.

Intel Barebones Media Center PC

mcreasy — Fri, 18 Feb 2005 17:01:00 GMT

This is pretty cool if you're looking to build your own Media Center PC. Intel have started producing barebones systems in a case that wouldn't look out of place with other A/V equipment. All you need to add is a CPU (an Intel P4 of course), hard drive and RAM.

The motherboard is based on the Intel 915P chipset with integrated 8-channel Intel HD audio with coax and optical out. There's a dual NTSC tuner in the system as well, although it's not clear which brand it is. Also pre-installed is a PCI-E x16 ATI X300LE graphics card - I'd have preferred something more powerfully, but it will be fine for SD content. There's a combo DVD/CD-RW drive, a dual layer DVD+/-RW would have been a nice upgrade. There's a built in Ethernet port as well as wireless (no 'a' just 'b' and 'g'), a flash card reader, front panel display and a it comes with a remote control for Media Center.

It looks like you could build a reasonable Media Center with it, but there's room for improvement. It also seems a little on the expensive side to me.

Take a look at it at NewEgg.com via eHomeUpgrade.com

Update for Media Center Extender for Xbox now available

mcreasy — Fri, 18 Feb 2005 04:15:00 GMT

There's an update for MCX for Xbox available on Xbox Live now that will allow you to play back CGMS-A content (HBO etc...). You should get prompted about the update next time you log into Live.

If you don't have Xbox Live you can request the update here.

Installing applications on Media Center

mcreasy — Thu, 17 Feb 2005 21:38:00 GMT

In response to an emailed question from Mike Kaltschnee about how to install applications on Media Center I thought I'd provide my thoughts on the subject.

First, do you really need to install something? Let's tackle what do if you just want to create some links to your web based application.

Creating links to applications

There are a few ways of getting a link onto a PC...

Provide a MCL file that the end user can download and put on their PC. This is great for sharing links to sites for technical users, but doesn't work that well for non-technical users. If you choose this option you need to get the user to save the MCL file to their PC and then double click on it. This will start Media Center and navigate to your application. Your application should then make use of one of the following APIs to get a link installed.

But the user has the MCL file, why do I need to create another one? To get your application to show up in More Programs inside Media Center that MCL file needs to be in a specific location and many users will not understand how to save the file in the right place. Also your initial MCL may point to a sign-up page and your link could point to the main page of your application.

Creating a link using CreateMCL

NOTE: This API should only be used for Media Center 2004 clients. If the target is Media Center 2005 use the RegisterApplication API (see below).

The SDK describes how to use the API, but I have a few extra notes...

"StartImageUrl" will be ignored on Media Center 2005
Ignore the "Category" param or specify 0.
"Type" should always be 0

Creating a link using RegisterApplication

I've talked a little bit about this API before, but I'll say a bit more here.

This is the preferred way of creating links (or "entrypoints" as we like to call them) in Media Center 2005 and it has a number of advantages:

You can register your application to multiple places instead of just More Programs.
- "More With This" categories will let your application appear in when a user brings up the context menu on a piece of media and clicks the "More..." button. You'll also get information on the media they clicked on, so if you're building a photo sharing application you'd want to register in the "More With This\Picture" category.
- "Services" categories allow your application to appear on the "More" pages that appear in each experience, i.e. "More Music"
- "New For Me" is a big topic and I'll cover this at a later date.
Using different categories you can create more than one link at a time.
This is the way to register add-ins.
You can register your application for all users of the PC

Installing your application

Creating a link is fine if your application is purely web based, but if you need to download something (an add-in for example) then you need to get the content on to the PC somehow.

If all you need to install are some ActiveX controls you can do that in Media Center, just as you would in IE.

If you need to install an add-in then there are a couple of things you need to do...

Creating an add-in installer

The SDK includes the basics on how to create an installer and simplifies how to register your application. This is the preferred way of installing an add-in.

Downloading the add-in

Media Center does not provide a special way of downloading files from the web and we recommend that you avoid trying to get users to download files via the 10' interface of Media Center as on a TV the download dialogs may be difficult read and understand. Instead you should get the user to download your installed from a standard website in Internet Explorer.

Assuming that the user is viewing your 10' website in Media Center and wants to download your add-in:

Warn the user that to install the add-in they will need to visit a website in Internet Explorer
Direct the user to the web page
1. In Media Center 2005 use the CreateDesktopShortcut API to either create a shortcut on the desktop to your website or open it directly in IE (note if Media Center is full screen IE will open behind Media Center, so you'll need to exit DirectX exclusive mode first)
2. In Media Center 2004 directly navigate to the page and Media Center will give the user the option of viewing the page in Media Center or creating a shortcut to open in IE later.

Naturally the same steps could be used for installing something other than an add-in.

Sony will offer an upgrade to Media Center 2005

mcreasy — Mon, 31 Jan 2005 17:33:00 GMT

If you've got a Sony Media Center PC and want an upgrade to Media Center 2005, you'll want to click here.

Improving "My Pictures"

mcreasy — Fri, 31 Dec 2004 17:59:00 GMT

eHomeUpgrade talks about how to improve the My Pictures experience in Media Center.

There's some good ideas there. Some that I've thought of before and would like to see and some that I haven't. They noticed that a slideshow always starts with the same photo which annoys me as well, but I've learnt to live with it. They mention meta-data on photos, which is a good idea, but I already keep my photos organised by folder which does most of what they suggest.

There's a suggestion of a My Art feature - I think this is what Gallery Player is targeted at. It's now in Online Spotlight.

I've been thinking of doing some work on my personal website to make it display photos differently when viewed from Media Center. Maybe I'll work on that this weekend. The pages are written in ASP.NET so I can easily customise it to do something different for Media Center.

Who has some great ideas about how My Pictures could be improved?

Got an Extender? Got HBO? You'll want this update.

mcreasy — Tue, 21 Dec 2004 02:44:00 GMT

Now you can watch copy protected TV on your Extender.

Update for the HP model.

Update for the Linksys model.

Just in time for the holidays. Enjoy everyone.