net page 30 - Dave's Blog

Crossing Four Way Stops Fast and Searching Closed Caption MCE Videos: More Stolen Thoughts

2008 Jan 22, 9:56

More ideas stolen from me in the same vein as my stolen OpenID thoughts.

Fast Pedestrian Crossing on Four Way Stops. In college I didn't have a car and every weekend I had weekly poker with friends who lived nearby so I would end up waiting to cross from one corner of a traffic lit four way stop to the opposite corner. Waiting there in the cold gave me plenty of time to consider the fastest method of getting to the opposite corner of a four-way stop. My plan was to hit the pedestrian crossing button for both directions and travel on the first one available. This only seems like a bad choice if the pedestrian crossing signal travels clockwise or counter clockwise around the four way stop. In those two cases its better to take the later of the two pedestrian signal crossings, but I have yet to see those two patterns on a real life traffic stop. I decided recently to see if my plan was actually sound and looked up info on traffic signals. But the info didn't say much other than "its complicated" and "it depends" (I'm paraphrasing). Then I found some guy's analysis of this problem. So I'm done with this and I'll continue pressing both buttons and crossing on the first pedestrian signal. Incidentally on one such night when I was waiting to cross this intersection I heard a loud multi-click sound and realized that the woman in the SUV waiting to cross the intersection next to me had just locked her doors. I guess my thinking-about-crossing-the-street face is intimidating.

Windows Searching Windows Media Center Recorded TV's Closed Captions. An Ars-Technica article on a fancy DVR described one of the DVRs features: full text search over the subtitles of the recorded TV shows. I thought implementing this for Windows Media Center recorded TV shows and Windows Search would be an interesting project to learn about video files, and extending Windows Search. As it turns out though some guy, Stephen Toub implemented Windows Search over MCE closed captions already. Stephen Toub's article is very long and describes some other very interesting related projects including 'summarizing video files' which you may want to read.

stolen-thoughts windows search mce windows traffic closed captions four-way-stop windows-media-center

IPv6 Roundup: Address Syntax on Windows

2008 Jan 9, 11:34

IPv6 address syntax consists of 8 groupings of colon delimited 16-bit hex values making up the 128-bit address. An optional double colon can replace any consecutive sequence of 0 valued hex values. For example the following is a valid IPv6 address: fe80::2c02:db79

Some IPv6 addresses aren't global and in those cases need a scope ID to describe their context. These get a '%' followed by the scope ID. For example the previous example with a scope ID of '8' would be: fe80::2c02:db79%8

IPv6 addresses in URIs may appear in the host section of a URI as long as they're enclosed by square brackets. For example: http://[fe80::2c02:db79]/. The RFC explicitly notes that there isn't a way to add a scope ID to the IPv6 address in a URI. However a draft document describes adding scope IDs to IPv6 addresses in URIs. The draft document uses the IPvFuture production from the URI RFC with a 'v1' to add a new hostname syntax and a '+' instead of a '%' for delimiting the scope id. For example: http://[v1.fe80::2c02:db79+8]/. However, this is still a draft document, not a final standard, and I don't know of any system that works this way.

In Windows XPSP2 the IPv6 stack is available but disabled by default. To enable the IPv6 stack, at a command prompt run 'netsh interface ipv6 install'. In Vista IPv6 is the on by default and cannot be turned off, while the IPv4 stack is optional and may be turned off by a command similar to the previous.

Once you have IPv6 on in your OS you can turn on IPv6 for IIS6 or just use IIS7. The address ::1 refers to the local machine.

In some places in Windows like UNC paths, IPv6 addresses aren't allowed. In those cases you can use a Vista DNS IPv6 hack that lives in the OS name resolution stack that transforms particularly crafted names into IPv6 addresses. Take your IPv6 address, replace the ':'s with '-'s and the '%' with an 's' and then append '.ipv6-literal.net' to the end. For example: fe80--2c02-db79s8.ipv6-literal.net. That name will resolve to the same example I've been using in Vista. This transformation occurs inside the system's local name resolution stack so no DNS servers are involved, although Microsoft does own the ipv6-literal.net domain name.

MSDN describes IPv6 addresses in URIs in Windows and I've described IPv6 addresses in URIs in IE7. File URIs in IE7 don't support IPv6 addresses. If you want to put a scope ID in a URI in IE7 you use a '%25' to delimit the scope ID and due to a bug you must have at least two digits in your scope ID. So, to take the previous example: http://[fe80::2c02:db79%2508]/. Note that its 08 rather than just 8.

roundup ip windows ipv6 technical microsoft boring syntax

Theme Options

2007 Dec 24, 12:41These days it seems like there's a social sharing website for everything representable as bits. Like Scribd for (mostly legal) documents, SciVee for scientific research videos, Wordie for words, and Kuler for color themes. Kuler seems like a ridiculous website (overkill) but I had been meaning to update my homepage's color design and Kuler has an RSS based REST API. The API lets you obtain things like the most recently added color themes or the most popular or all themes containing the color dark red, etc... So of course rather than update my website's design I hooked up my css to the color themes coming out of Kuler. Select my main page's color theme from a list of random Kuler themes. As I'm sure the regular readers can guess I use an xslt and blah blah blah... It looks OK with Silver Surfer and Happy Hipo but in general changing the colors this way doesn't produce something pretty.

When reading about Kuler I found that they may have stolen the whole idea wholeslae from ColourLovers. They discuss the thievery in an article on their blog. I would have switched over to ColourLovers out of principle but they don't have an easily accessible API.colourlovers color xslt theme homepage technical kuler design

Windows Media Center and Zune Integration Hack

2007 Nov 28, 1:23One of the new Zune features that had me the most excited was the claimed improved Windows Media Center integration which unfortunately turned out to simply mean support for the Win MCE video format (with an exception for HD). I wanted to be able to pick shows recorded by my Win MCE and have the Zune automatically sync up the latest episodes. However, with the improved podcast support in the Zune software one can easily create a ridiculous hack to accomplish this.

The new Zune software has podcast support which does everything I'd want to do with a Win MCE recorded TV series so the goal is to shoehorn a TV series into a Zune podcast. An overview of the steps: Create an XSLT that converts Win MCE data to a podcast, run the XSLT as a scheduled task every few hours per TV series, setup a Web server pointed at the resulting podcasts and the Win MCE Recorded TV directory, and subscribe to the resulting podcasts in the Zune software.

1. Reading through the Win MCE data stored as an XML file in "C:\ProgramData\Microsoft\eHome\Recording\Recordings.xml" and the spec for podcasts I created an XSLT to convert a series from Win MCE data to a podcast.
2. I added a new task to the Scheduled Tasks to run my XSLT using my xsltproc.js script. The task runs a handful of commands that look something like the following:

   C:\windows\system32\wscript.exe C:\users\dave\bin\xsltproc.js C:\Users\Dave\Documents\trunk\development\mce-zune\mce-to-podcast.xslt C:\ProgramData\Microsoft\eHome\Recording\Recordings.xml --param title "The Daily Show With Jon Stewart" --param max 4 --param baseURI "http://groucho/" --param thisRelURI "tds.xml" -o "D:\recorded tv\tds.xml"

   For each TV series I run a command like the above and that outputs a podcast for that series into my "D:\Recorded TV\" directory.
3. Zune only allows http URIs for its podcasts so I installed a web server on my Win MCE server. I'm running Vista Ultimate so it was quick and easy for me to install IIS7 but any Web server will do. Then I pointed it at "D:\Recorded TV\".
4. Once all the above was done I just subscribed to the resulting podcasts via my Web server and viola! Since I'm forced to use a Web server I can even run the Zune software on a machine other than my Win MCE server. You can see a screen-shot above of my Zune software showing my Colbert Report podcast.

technical xml mce hack windows media center zune windows xslt podcast

Zune Software Update

2007 Nov 19, 3:47I really appreciate that the first gen Zune's get the new Zune's firmware and software. I like the updated Zune software personally because its faster and simpler, has better podcast support, and the whole social thing has is on their website now. So, I guess I like the software because it has new features that should have been there in the first place.

The social thing is like a Zune social network. It uses your Xbox Live friends to seed your Zune friends list, lets you do the expected social network stuff, lets you preview songs, and unlike first gen Zunes which required face to face time with other Zune owners, allows you to send songs to people. It also lets you display your recently played tracks and your favorite tracks, similar to what Last.FM has, via a Zune Card. I like the Zune Card from a technical perspective because it separates the Zune Card view, written in flash from the User Card data which is in XML. I hope they intend to keep the XML available via this UserCard Service because I think there's potential to easily do cool things.microsoft technical music zune social