Scott Hanselman

While I was running around Mix09 and the MVP Summit this last few weeks I was taking video with my Flip Ultra and my new Creative Vado HD (I took the Flip Mino HD back, as I thought the quality was poor). I put a bunch of these videos up on Channel 9 and declared it "Hanselminutes On 9." It's not official, but maybe if you leave comments they'll make it a regular thing. Some of the videos are pretty cool. Others, totally useless. ;)

While Channel 9 recompresses my already compressed streams, I want to point out that the letterboxed 16:9 videos were done with the Creative Vado HD, then the aspect ratio was changed with Expression Encoder. The 4:3 videos were done with my regular Flip Ultra. Let me know which ones you prefer more.

If you like this idea, I'll start taking my cameras everywhere and when I talk to interesting people, I'll throw the videos up on Channel 9 as I make them. I started doing this almost two years ago with Rory and a bunch of videos were recorded, but those recordings are lost in the sands of time. Here's the first "pilot" episode of Hanselminutes on 9 with Polita Paulus, though. You can see from the old comments that it was a pretty decent show, that.

Johnny Lee on Computer Vision Wow. I just bumped into Johnny Lee in the halls here at Mix09. I'm a huge fan boi with a man-crush on this dude. You've seen Johnny before on Channel 9 talking to Robert Hess.  Johnny's a legend (in my mind) in the computer vision space, and he put up with me gushing at him here at Mix09. We chatted in the hall about computer vision, what he's working on, how he got the gig at Microsoft and where he sees the future of human-computer-interaction.	Eilon Lipton and the ASP.NET MVC Rumors In this episode of Hanselminutes on 9, I break into Eilon Lipton's office and demand the real scoop on who or what wrote ASP.NET MVC. The word on the street is that ScottGu wrote the original prototype, codenamed "Scalene" on an airplane. Is this true? I pretend to turn off my camera and fool Eilon, the lead developer on ASP.NET MVC, to give up the goods. See how he gazes lovingly at me? That's just the kind of bromance that Eilon and I have.
Phil Haack on the ASP.NET MVC 1.0 Release This Hanselminutes on 9 video was filmed at the MVP Summit on the Redmond Campus. I was on campus for the week with my trusty Flip Video camera and I pulled Phil Haack outside and demanded the real scoop on ASP.NET MVC. I beat him about the head and ears and asked questions like "what qualifies you to be a PM at Microsoft!" If you like this kind of hard-hitting journalism, tell the folks at Channel 9 to give "HanselminutesOn9" its own Tag or Category for Pete's Sake!	Joel Spolsky and Jeff Atwood preparing for StackOverflow Keynote Security is tight here at Mix09 but I've snuck past the guards and followed Joel Spolsky (JoelOnSoftware) and Jeff Atwood (CodingHorror) up the escalator to their Keynote Rehearsal. The fans went wild! Well, one fan. A lady on the escalator recognized them. But still! The air is electric. Let's listen in...
Rob Conery and the MVC Storefront I'm wandering the halls in Building 42 and bump into the man himself, Rob Conery. This is amazing for a number of reasons, not the least of which being that Rob lives in Hawaii. I put the hot lights up to Rob and get him to confess to a number of transgressions. Turns out he IS still working on the MVC Storefront and will be giving us the source in some form or another. Most likely in the form of source. So, we got that going for us.	Brad Wilson has Lunch In this completely useless video (you have been warned),  Scott bumps into Brad Wilson in the halls of Building 42 and finds out what Brad is having for lunch. He also says a little about the Data Annotation-based Model Binder that they showed at Mix 09. A glimpse at what is to come in the unholy marriage of ASP.NET MVC and ASP.NET Dynamic Data. I shudder to think of the possibilities. A small shudder, to be clear, but it's there. Almost palpable.

I also want to point out, that while it's not totally obvious, there are some tiny icons next to the images when you get to the Channel 9 site. They look like this:

These icons are clickable and mean each video is available in a number of formats, including portable device ones, and also that you can easily share these links/videos on various social networking sites. So please do.

Enjoy!

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

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I had the pleasure of interviewing Pete Brown this last week and talking about the Silverlight 3 Commodore 64 Emulator he's been working on. He just launched the CodePlex site a few minutes ago (my time), but I've had the code for a while to play with. You can read Tim Heuer's blog post for details on how to get started with Silverlight 3 Beta and the tools you'd need or see some video of the emulator in action.

Keep in mind that this is a labor of love that Pete's doing, and the code has been written in "gett'er done" mode, so it won't win any awards for aesthetic. A lot of the code as been ported directly over from Open Source C++ in the Frodo Emulator or from Sharp C64.

It does have some pretty clever ideas, though, and I thought I'd take a look at those in this Weekly Source Code (which I promise to make more Weekly, starting now).

Dynamically Creating a Video Stream

Pete wanted the screen to draw as fast as possible, which is 50Hz (50 times a second). He was originally creating PNGs or Bitmaps and throwing it up on the screen as fast as possible, but then a member of the Silverlight team suggesting "making a video." What did he mean by "making a video?" He suggested actually using a Silverlight MediaElement (the "video player" control) and acting as a DataSource for a video. He's dynamically creating a movie that never ends.

This means the UI XAML is basically:

<MediaElement x:Name="VideoDisplay"
  Grid.Row="0"
  Grid.Column="0"
  VerticalAlignment="Top"
  Stretch="Uniform"
  IsHitTestVisible="False"
  Margin="4" />

And in the code behind he creates a VideoMediaStreamSource the had blogged about here, deriving from MediaStreamSource:

_video = new VideoMediaStreamSource(TheSID.Renderer.AudioStream, C64Display.DISPLAY_X, C64Display.DISPLAY_Y);

and it looks like:

private byte[][] _frames = new byte[2][];
public VideoMediaStreamSource(int frameWidth, int frameHeight)
{
    _frameWidth = frameWidth;
    _frameHeight = frameHeight;

    _framePixelSize = frameWidth * frameHeight;
    _frameBufferSize = _framePixelSize * BytesPerPixel;

    // PAL is 50 frames per second
    _frameTime = (int)TimeSpan.FromSeconds((double)1 / 50).Ticks;

    _frames[0] = new byte[_frameBufferSize];
    _frames[1] = new byte[_frameBufferSize];

    _currentBufferFrame = 0;
    _currentReadyFrame = 1;
}

public void Flip()
{
    int f = _currentBufferFrame;
    _currentBufferFrame = _currentReadyFrame;
    _currentReadyFrame = f;
}

When he wants to write a pixel to his buffer, as he often does at the low level:

public void WritePixel(int position, Color color)
{
    int offset = position * BytesPerPixel;

    _frames[_currentBufferFrame][offset++] = color.B;
    _frames[_currentBufferFrame][offset++] = color.G;
    _frames[_currentBufferFrame][offset++] = color.R;
    _frames[_currentBufferFrame][offset++] = color.A;

}

When it comes time to get a sample, the MediaSteamSource calls GetSampleAsync:

protected override void GetSampleAsync(MediaStreamType mediaStreamType)
{
    if (mediaStreamType == MediaStreamType.Audio)
    {
        GetAudioSample();
    }
    else if (mediaStreamType == MediaStreamType.Video)
    {
        GetVideoSample();
    }
}

He grabs a video frame from his buffer, he make a sample and reports he's done:

private void GetVideoSample()
{
    _frameStream = new MemoryStream();
    _frameStream.Write(_frames[_currentReadyFrame], 0, _frameBufferSize);

    // Send out the next sample
    MediaStreamSample msSamp = new MediaStreamSample(
        _videoDesc,
        _frameStream,
        0,
        _frameBufferSize,
        _currentVideoTimeStamp,
        _emptySampleDict);

    _currentVideoTimeStamp += _frameTime;

    ReportGetSampleCompleted(msSamp);
}

His app makes frames as fast as they can, putting them in the buffer at 50Hz, and the MediaElement requests frames from his VideoMediaStreamSource as fast as it can take them.

Emulating a 1541 Disk Drive

There's a file format in the world of C64 emulators that everyone has standardized on called .d64. The D64Drive.cs file contains the meat of the code to read these image files. "The *.D64 file format is a 1:1 copy of all sectors as they appear on a floppy disk."

Most of it looks like C/C++ code, because it once was. Some of it used to be "unsafe" C# code, writing with the unsafe keyword so the runtime could pin down pointers and use them directly.

I love it when there's things like byte[] magic. ;) Seems like every binary file format has them. In this case, we're looking for 0x43, 0x15, 0x41 and 0x64. Notice that 0x43 is "C", while the second and third bites are "1541" with the final "64" in there. ;)

private void open_close_d64_file(string d64name, Stream fileStream)
{
    long size;
    byte[] magic = new byte[4];

    // Close old .d64, if open
    if (the_file != null)
    {
        close_all_channels();
        the_file.Dispose();
        the_file = null;
    }


    // Open new .d64 file
    if (fileStream != null)
    {
        //the_file = new FileStream(d64name, FileMode.Open, FileAccess.Read);
        the_file = fileStream;

        // Check length
        size = the_file.Length;

        // Check length
        if (size < NUM_SECTORS * 256)
        {
            the_file.Dispose();
            the_file = null;
            return;
        }

        // x64 image?
        the_file.Read(magic, 0, 4);
        if (magic[0] == 0x43 && magic[1] == 0x15 && magic[2] == 0x41 && magic[3] == 0x64)
            image_header = 64;
        else
            image_header = 0;

        // Preset error info (all sectors no error)
        Array.Clear(error_info, 0, error_info.Length);

        // Load sector error info from .d64 file, if present
        if (image_header == 0 && size == NUM_SECTORS * 257)
        {
            the_file.Seek(NUM_SECTORS * 256, SeekOrigin.Begin);
            the_file.Read(error_info, 0, NUM_SECTORS);
        }
    }
}

This is all fun stuff, but as Pete said to me in an email:

"PS. My “real” code *never* looks like this. This is full of c++-isms and just plain “let me see if I can get this to work” junk."

So, take it for what it is. It's awesome.

References

• Frodo Emulator: http://frodo.cebix.net/
• Sharp C64: http://sourceforge.net/projects/sharp-c64
• Video of the Emulator in action

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

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My one-hundred-and-fifty-fifth podcast is up. Scott digs deep with Pete Brown about the Commodore 64 Emulator he is writing in Silverlight 3. Is Silverlight fast enough? What about offline support? What Silverlight 3 features made the job easier? All this and next steps in this week's show. See video of the emulator in action!

Subscribe:

• Download: MP3 Full Show #155
• Play in your browser.

Do also remember the complete archives are always up and they have PDF Transcripts, a little known feature that show up a few weeks after each show.

Telerik is a sponsor for this show!

Building quality software is never easy. It requires skills and imagination. We cannot promise to improve your skills, but when it comes to User Interface, we can provide the building blocks to take your application a step closer to your imagination. Explore the leading UI suites for ASP.NET and Windows Forms. Enjoy the versatility of our new-generation Reporting Tool. Dive into our online community. Visit www.telerik.com.

As I've said before this show comes to you with the audio expertise and stewardship of Carl Franklin. The name comes from Travis Illig, but the goal of the show is simple. Avoid wasting the listener's time. (and make the commute less boring)

Enjoy. Who knows what'll happen in the next show?

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

About   Newsletter

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My one-hundred-and-fifty-fourth podcast is up. Scott's at Mix09 in Las Vegas this week and he sits down with Chris Woods, a Program Manager on the Mobile Browse Platform Team. They've just open sourced a MASSIVE database of mobile device capabilities, enabling better mobile development for ASP.NET developers. You can also check out Chris's Mix session on Mobile, or my NerdDinner ASP.NET MVC talk.

Subscribe:

• Download: MP3 Full Show #154
• Play in your browser.

Do also remember the complete archives are always up and they have PDF Transcripts, a little known feature that show up a few weeks after each show.

Telerik is a sponsor for this show!

Building quality software is never easy. It requires skills and imagination. We cannot promise to improve your skills, but when it comes to User Interface, we can provide the building blocks to take your application a step closer to your imagination. Explore the leading UI suites for ASP.NET and Windows Forms. Enjoy the versatility of our new-generation Reporting Tool. Dive into our online community. Visit www.telerik.com.

As I've said before this show comes to you with the audio expertise and stewardship of Carl Franklin. The name comes from Travis Illig, but the goal of the show is simple. Avoid wasting the listener's time. (and make the commute less boring)

Enjoy. Who knows what'll happen in the next show?

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

About   Newsletter

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UPDATE from 2011: These View Engines have a subtle release mode caching bug. Peter Mourfield and I have released a better MobileViewEngine for ASP.NET MVC 3 that is closer to what MVC 4 will look like. The updated blog post with the new MobileViewEngine is here.

I gave a talk at Mix 09 today called File | New Company: Creating NerdDinner.com with Microsoft ASP.NET MVC. It was a fun, if challenging talk to do. I did it it with no slides at all. Just me and Visual Studio. It was one of two talks at Mix that had just code. I wonder if it'll catch on? ;)

Anyway, it was quite the tightrope walk. I'll post the video here as soon as it's posted on the Mix 09 Sessions Site.

UPDATED: Here's the link to the video of my Mix09 talk:

Session Video: File | New Company: Creating NerdDinner.com with Microsoft ASP.NET MVC

The general structure was to start a File | New Company and build as much of NerdDinner.com as I could in the 75 minutes allotted.

Here's a few of the highlights...

XHTML Strict

I pointed out how nice and easy it is to get a site to validate as XHTML Strict using ASP.NET MVC. You've got complete control over every bit that goes out on the wire. Kudos to Michael Bach for caring. I'm still not 100% convinced that XHTML Strict is as crucially important as the <ul-mafia/> says it is, but it's a simple thing to do it you keep the markup clean, simple and semantic. ;)

Mobile and ASP.NET MVC

The talk was about developing on ASP.NET MVC, not about mobile, but it was easy to make the site available on mobile devices when I got wind of what the Mobile Browse Platform Team (in Microsoft's Dublin office) was releasing at Mix.

They released the Mobile Device Browser File on CodePlex under the Ms-PL license. It's created from a database from many sources, including the popular WURFL mobile device capabilities database, actual device tests, UAProfs, contributions, logs, and elsewhere. These sources are composited, stored in a database of thousands and thousands of devices. Then that's combined with the actual logs of mobile device traffic and this file with the top 1500 or so actual devices is created to get the broadest reach with a manageable file size.

It's a mobile.browser file that contains definitions for hundreds of the top individual mobile devices and browsers that hit Microsoft mobile sites. At run time, ASP.NET uses the information in the request header to determine what type of device/browser has made the request.

It detects the mobile device hitting your site and makes available 67 capabilities describing the requesting device. These capabilities range from screen size to cookie support to CSS support. It's everything you need to adaptively render content for mobile phones and devices.

This information is exposed to the developer through the Request.Browser property. The format of the .browser file is XML and the schema is defined here: Browser Definition File Schema. The Browser Definition File was introduced in the .NET Framework version 2.0. In earlier versions of the .NET Framework, the browserCaps element was used to define browser definitions in configuration files.

Now, ASP.NET MVC doesn't know anything about Mobile. Here's what I did to enable NerdDinner on Windows Mobile and iPhone.

First, I downloaded the new Mobile Device Browser File and put it in \App_Browsers\Devices in my ASP.NET project. Just by dropping this file in the App_Browser\Devices folder, I automatically get all these 67 capabilities populated in the Request.Browser option. I can address them like Request.Browser["AjaxSupportsGetElementByID"]. Just open up the mobile.browser file to see all your choices. There's also extensive documentation. They'll welcome  bug reports and patches.

The guys at Ascentium that I met at Mix threw me some code and we created a basic MobileCapableWebFormViewEngine. Kind of a long name, but basically I need to have ASP.NET MVC look in different folders for a View if the device is mobile.

For example, ordinarily if you're in the Home Controller and the Index action, the ViewEngine's FindView() method gets called and will look in /Views/Home for Index.aspx.

The Mobile ViewEngine needs to detect the device and change where we look. I could just make a "Mobile" version and call it a day. However, since we've got a nice tree structure here, why not set up:

• /Views/Home
• /View/Home/Mobile
• /View/Home/Mobile/iPhone
• /View/Home/Mobile/MobileIE

etc...so, now we can have many different files, any combination of them.

We can also have things fallback neatly. For example, we can create a really specific View, say, for a Nokia "Whatever" when it needs the Details, but that Nokia will use the standard Mobile view in all other situations. This is accomplished by just the folder convention.

Here's a simple example to start.:

public class MobileCapableWebFormViewEngine : WebFormViewEngine
{
    public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
    {
        ViewEngineResult result = null;
        var request = controllerContext.HttpContext.Request;

        // Avoid unnecessary checks if this device isn't suspected to be a mobile device
        if (request.Browser.IsMobileDevice)
        {
            result = base.FindView(controllerContext, "Mobile/" + viewName, masterName, useCache);
        }

        //Fall back to desktop view if no other view has been selected
        if (result == null || result.View == null)
        {
            result = base.FindView(controllerContext, viewName, masterName, useCache);
        }

        return result;
    }
}

This can be expanded on like this (and in a number of other ways...switch statements, tables, conventions, it's up to you to map the Views as you like.

public class MobileCapableWebFormViewEngine : WebFormViewEngine
{
    public override ViewEngineResult FindView(ControllerContext controllerContext, string viewName, string masterName, bool useCache)
    {
        ViewEngineResult result = null;
        var request = controllerContext.HttpContext.Request;

        //This could be replaced with a switch statement as other advanced / device specific views are created
        if (UserAgentIs(controllerContext, "iPhone"))    
        {
            result = base.FindView(controllerContext, "Mobile/iPhone/" + viewName, masterName, useCache);
        }

        // Avoid unnecessary checks if this device isn't suspected to be a mobile device
        if (request.Browser.IsMobileDevice)
        {
            if (UserAgentIs(controllerContext, "MSIEMobile 6"))
            {
                result = base.FindView(controllerContext, "Mobile/MobileIE6/" + viewName, masterName, useCache);
            }
            else if (UserAgentIs(controllerContext, "PocketIE") && request.Browser.MajorVersion >= 4)
            {
                result = base.FindView(controllerContext, "Mobile/PocketIE/" + viewName, masterName, useCache);
            }

            //Fall back to default mobile view if no other mobile view has already been set
            if ((result == null || result.View == null) &&
                            request.Browser.IsMobileDevice)
            {
                result = base.FindView(controllerContext, "Mobile/" + viewName, masterName, useCache);
            }
        }

        //Fall back to desktop view if no other view has been selected
        if (result == null || result.View == null)
        {
            result = base.FindView(controllerContext, viewName, masterName, useCache);
        }

        return result;
    }

    private bool UserAgentIs(ControllerContext controllerContext, string userAgentToTest)
    {
        return (controllerContext.HttpContext.Request.UserAgent.IndexOf(userAgentToTest, StringComparison.OrdinalIgnoreCase) > 0);
    }
}

Remember when I said there were 67 capabilities for each of the devices? I might need a custom view for a device, but in many instances, I might just want to modify some small aspect of a few based on the browser's characteristics like screen width or height. I could control the Mobile ViewPort like this for phones that support it.

<meta name="viewport" content="width=<%= Request.Browser["ScreenPixelsWidth"] %>, height=<%=Request.Browser["ScreenPixelsHeight"]%>"/>

A more advanced example might be this. Say I store all my images in PNG format, but I come upon a phone that doesn't support PNG. I might automatically transcode my PNGs into JPGs. Same with a phone that supports WAV but not MP3.

Windows Mobile and iPhone

Armed with this, it was just a few hours work for my simple NerdDinner app to get mobile enabled. Now that I'm learning more about what devices can do what, I'll check all this in and continue to add functionality.

For iPhone I used Joe Hewitt's IUI JavaScript and CSS Framework (and the iPhone Simulator). The iPhone includes a lot of -webkit CSS extensions so the view did need be custom. It just doesn't work at all on other browsers, but it looks great on the iPhone. For Windows Mobile, I downloaded the free Windows Mobile 6.1.4 Emulator Images and the Device Emulator.

Again, I can do whatever I like with the markup, so on these devices, clicking the phone number initiates a call, clicking a map takes you to a mobile map solution, etc.

I'll be checking this in to the NerdDinner CodePlex project in the next few days. I'm really stoked that these guys released this data file. I just dropped it in, and ASP.NET suddenly got a lot smarter and I can now make great sites for any device. After this prototyping exercise, it's time for me to think about the interaction design for the mobile experience, rather than just "down-porting" the desktop site.

All in all, great fun, and a boon to ASP.NET and developers interested in mobile.

About Scott

Scott Hanselman is a former professor, former Chief Architect in finance, now speaker, consultant, father, diabetic, and Microsoft employee. He is a failed stand-up comic, a cornrower, and a book author.

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