codeblog code is freedom — patching my itch

8/9/2006

talk to me about Sendpage

Filed under: Blogging,Networking — kees @ 4:50 pm

Like I mentioned before, I’ll be in San Francisco at Linux World Expo next week. Besides presenting, I’ll also be at a Birds-of-a-Feather on “Network, Device, and Environment Monitoring” on Wed (8/16) at 6pm in Room 309, where I’ll be talking about Sendpage. I’ve been told this BoF is open to anyone with an “exhibits” pass which, prior to LWE starting, is free! So, if you’re in the area, come hang out. :)

© 2006, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License.
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8/7/2006

flag captured

Filed under: Reverse Engineering,Security — kees @ 11:19 pm

I can’t believe it. We won DefCon CTF. I have no idea what to say. It just all came together this year. Great team, great contest.

And to make it even sweeter, since CTF is a “Black Badge” contest, I never have to pay to get into DefCon again! Although, at this point, I might pay several years worth of admission in exchange for lots of time to sleep. :)

UPDATE: nice write-up at the U of Florida.

© 2006, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License.
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8/2/2006

mythtv cutlist to mplayer EDL file

Filed under: Multimedia — kees @ 8:47 pm

I was too lazy to walk over to my TV, so I decided to watch my MythTV recordings on my desktop without having installed a MythTV frontend. Via the magic of MythTVfs, I started watching a recent Stargate episode.

Before the opening credits had finished, I knew I was already going to miss MythTV’s commercial flagging. So started the investigation into where in the world MythTV stores that information. I was imagining adding “.edl” files to MythTVfs automatically, etc.

In MythTV 0.19, using “mythcommflag”, you can get the “Cut” list, but not the “Commercial Skip” list. (Think of the latter as a “Cut Hint” list.) The command for this is:

mythcommflag –getcutlist -c 1059 -s 20060728210000

In MythTV 0.20, you’ll be able to use “–getskiplist”. Since I’m still using 0.19, I had to go directly to the “mythconverg” database to get the details. The marks are stored in the “recordedmarkup” table. The mark types I care about are: 4: Commercial Start, 5: Commercial End. This SQL query gets me somewhere:

SELECT mark, type FROM recordedmarkup WHERE chanid = “1059″ AND starttime = “20060728210000″ AND (type = 4 OR type = 5) ORDER BY mark;

However, mplayer’s EDL file format expects time, not frame number. MythTV stores frame number. Luck for us, it’s all NTSC MPEG2, so we’re at 29.97 frame per second, and I can modify the SQL:

SELECT mark/29.97, type FROM recordedmarkup WHERE chanid = “1059″ AND starttime = “20060728210000″ AND (type = 4 OR type = 5) ORDER BY mark;

Now I just have to get the pairs on a single line with a trailing “0″ for mplayer to know to skip that time frame:

echo ‘SELECT mark/29.97 FROM recordedmarkup WHERE chanid = “1059″ AND starttime = “20060728210000″ AND (type = 4 OR type = 5) ORDER BY mark;’ | mysql -B –skip-column-names | xargs -l2 | awk ‘{print $0 ” 0″ }’

Combined with some logic to extract the channel and starttime for a given recording, I’ve now got a really crazy wrapper script that’ll let me mplayer a recording after generating an EDL cutlist.

(With thanks to Ken’s excellent collection of “merge pairs of lines into single lines” short cuts.)

© 2006, Kees Cook. This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 License.
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