Monthly Archive for January, 2009

Evaluating codec freedom

I was recently asked about how free the Vorbis and Theora codecs are, particularly with respect to gratis versus libre. The answer to this question is more complicated than it looks and requires a deeper look into the difference between a specification and an implementation.
Continue reading ‘Evaluating codec freedom’

TEDTalks Downloader 0.1 released

TEDTalks Downloader, which downloads all videos from TEDTalks, is now available:

To use it, you will need a POSIX shell and wget or curl. If you are using Ubuntu or Mac OS X, you already meet the requirements. If you are using Windows, you will need to get a POSIX shell such as MSYS and wget for Windows.

To run TEDTalks Downloader, make sure the script is executable (chmod u+x should do it) and then run ./, preferably in an empty directory. The script will then download the TEDTalks feed, create a videos directory, and start downloading videos to it.

If TEDTalks Downloader is interrupted while running, you can run it again from the same place and it will automatically start where it left off. Also, if there are more TEDTalks available, running TEDTalks Downloader again will download the new talks without re-downloading all the other talks.

This tool was made in response to a request on my TEDTalks download script and MythTV metadata article. You can find more information about getting TEDTalks data in MythTV from there.

If you have any comments or questions about TEDTalks Downloader, please let me know by posting a comment to this article or contacting me directly.

The codec dilemma

Every day millions of videos are watched on video hosting sites like YouTube. Most viewers don’t think of how the videos are stored or how they get displayed on one’s computer. But these are critical questions in determining who is able to watch online videos and how much money they need to pay to do it, even on free hosting sites. Let me start by explaining what a “codec” is.
Continue reading ‘The codec dilemma’

Why Flash is doomed

In my previous post (“Why I haven’t installed a Flash player“), I tried to convince people why supporting Adobe Flash by installing a player was a bad idea. My hope was that efforts like mine would reduce the number of sites using Flash and eventually eliminate non-standard technologies like Flash from the web. Recent events made me realize why such efforts to get rid of Flash will pale in comparison to the natural phenomena that are already working together to seal Flash’s fate.
Continue reading ‘Why Flash is doomed’

What’s on a CharlieTicket magnetic stripe

I recently received 4 CharlieTickets from a very helpful person on the Stripe Snoop forums and took some time to read them and analyze the data. My interest in the CharlieTicket had been sparked by a presentation from a group from MIT students on security vulnerabilities in the MBTA ticketing and security systems. Here’s what I found:
Continue reading ‘What’s on a CharlieTicket magnetic stripe’