test 05/28/2007

Coding Horror: Beyond JPEG  Annotated

It’s surprising that the venerable JPEG image compression standard, which dates back to 1986, is still the best we can do for photographic image compression. I can’t remember when I encountered my first JPEG image, but JPEG didn’t appear to enter practical use until the early 90’s.

Microsoft, as Microsoft is wont to do, offers a closed-source alternative to JPEG 2000 known as HD Photo or Windows Media Photo. As of late 2006, Microsoft made the format 100% royalty free, and support for HD Photo is included in Windows Vista and .NET Framework 3.0. According to this Russian study, Files in Microsoft’s HD Photo format (.hdp, .wdp) are comparable to– but not better than— JPEG 2000. The study PDF has lots of comparison images, so you can decide for yourself.

Until a commonly used web browser supports JPEG 2000 or HD Photo, there’s no traction. I hope the next browser releases can move us beyond the ancient JPEG image compression format.

Mark Finkle’s Weblog » Firefox 3 – Bookmarks on Places Lands  Annotated

In addtion to the new features and UI this will allow in Firefox 3, it also gives extension developers a more powerful API for use in extensions. Places uses sqlite and the mozStorage to store bookmark and history data. Besides history and bookmark APIs, annonations, favicon and livemark service APIs are also available.

Dan Mill’s Mozillazine post has information about the upgrade and is a place where users can provide feedback.

digg api contest finalists – D’Lite

Mozilla Developer News » Blog Archive » Bookmarks on Places now enabled for Firefox 3 alpha 5  Annotated

The Firefox Places team has been hard at work to get the bookmarks portion of Places in shape for it to go out with Firefox 3 Alpha 5 scheduled later this month.  And we are excited to let you all know that last week we enabled the Places implementation of bookmarks on the trunk.  Although there is still much to be done, this is an important milestone for us.

ffmpeg tutorial How to Write a Video Player in less than 1000 lines

Facebook Developers | Get Started

Facebook Platform: 30+ Awesome Applications for Facebook

IT Resource Center forums – NTP – time server ‘rejected’  Annotated

Authorisation is not an issue. If you ‘Enable Authorisation’ this allows you to respond to encoded requests as well as any other requests. I’m receiving replies from the server – if I had failed authorisation it wouldn’t even reply. Thanks anyway; every penny helps!

I found something interesting in:
http://www.lnf.infn.it/computing/unix/ntp/debug.htm
Debug 8,
While the algorithm can tolerate a relatively large frequency error (over 350 parts per million or 30 seconds per day), various configuration errors (and in some cases kernel bugs) can exceed this tolerance, leading to erratic behavior. This can result in frequent loss of synchronization, together with wildly swinging offsets. … If the error increases by more than 22 milliseconds per 64-second poll interval, the intrinsic frequency must be reduced by some means.

This was written by the same bloke who wrote the protocol.

I was seeing 104 milliseconds per 64-second poll!! So that symptom is identified but no resolution.

I also found out more details of the NTP configuration for my router and above. This was not in line with NTP guidelines either. Consequently errors were increasing down the NTP path.

So in summary: NTP works because you have a selection of time servers. It can make intelligent decisions about which are the best tickers. Please note that when it makes it’s decisions it uses the distance to the root, the root dispersion as well as the delay, offset and jitter values for the peer, time intersections and a whole lot else!

I can only assume that a number of these parameters fell out side error bounds specified in the algorithm; unfortunately I haven’t found any definitive documentation to confirm this.

Due to corporate restrictions it looks like I’m going to have to revert to a dial up service.
An alternative solution is to set up ntpdate as a cron job but I don’t trust my source enough to do that!!