Thursday, October 15, 2009

ASX playlists

If you tried watching Nasa TV in my last post with Silverlight, you'd find that it wouldn't work. And once again the problem is with the ASX file - to be more specific, the exact same problem I had to find a quick fix for last week for Moonlight.

The ASX file I linked to links to another ASX file. This second ASX file has a copyright symbol in it (©), and it stores it in the CP1252 code page (i.e. the binary value 0xA9 - this is an illegal value in utf8). Now it seems like Silverlight expects the file to be in utf8 [1], and it errors out if it isn't [2].

Unfortunately I can't link to the real mms link, Yahoo seems to uses some sort of authentication ensuring that you got the link from the ASX playlist.

I notified Yahoo using their contact form about this, asking them to fix their ASX output, now let's see what happens...

[1] When there are no byte-order markers at least
[2] Windows Media Player plays the ASX file just fine.

Friday, October 9, 2009

Nasa TV

Interested by the NASA's crash landing on the moon, I wanted to watch the event live on my Linux machine. NASA has a few live TV channels, but none seemed to work on Linux. Until I discovered that they use ASX files to view the channels in Windows Media Player - turns out Silverlight (and by consequence Moonlight) also support ASX files. It was just a matter of creating a simple silverlight application referencing the ASX links. And that's what I did!

The bad thing is that our ASX support was a bit broken [1], and I had to fix it. This means that the currently released beta is not able to view the streams, you need to download brand new xpis from here: x86 / x64 (fair warning: these xpis are not tested at all, download at your own risk). Download, restart firefox and you should be able to watch the event live here.

(video is scaled 200%, quality is kinda bad, but that's how it's transmitted from NASA)

[1] IMHO ASX files are broken by themselves - they look like xml files but aren't (they don't escape special characters that xml files have to), and they're encoded in the current encoding of the machine generating the ASX file, and in order to correctly parse the file you have to know which encoding that is (the file itself doesn't know).