blog.layer2.org

I found at least one other person trying to find a way to extract a JPG snapshot out of a flash video using ffmpeg.

The above article suggests using ffmpeg to extract a PNG, and then convert that to a JPG (since the JPG will be much smaller). Instead, just use the correct arguments to ffmpeg:

ffmpeg -i movie.flv-vcodec mjpeg -vframes 1 -an -f rawvideo -s 320x240 movie.jpg

With -vcodec mjpeg the important argument.

Despite the well known fact that Verizon Can’t Do Math, I have to say that I am surprised to find that their FIOS service is pretty good. I’ve had it for over a month, and haven’t noticed it go down or have any speed problems.

More interestingly, I’ve actually found that they are pretty Linux-friendly. Actually, Linux-friendly might be too strong - lets just say that they have not locked me into using Windows for their service. I did have to use activatemyfios.verizon.net, which has a Windows/OS X only Firefox extension. But other than that, I haven’t felt the vendor lock-in blues.
Here are some good points:

• As far as I can tell, Verizon only blocks port 80. I run both SSH and HTTPS from my home box.
• Once I spoofed the correct MAC address, I was able to use my own non-Verizon router
• There is no PPPoE authentication or the like
• My IP address has not changed since I started the service
• Latency is very low (about 12ms to Google)
• Service has not gone down

I don’t use their phone or TV services, so I can’t comment on those. My guess would be that services like Vonage or Skype would work pretty well on my FIOS connection.

Bad points:

• The backup battery is supposedly pretty weak. It only provides voice service during a power outage, not Internet. For that, you’d have to use a UPS. Fortunately, I haven’t had the power go out.
• It took forever to get the service installed. Even though the previous house owner already had FIOS installed, they couldn’t come out for 2.5 weeks.

Verizon does pretty well here. So if you’re thinking about switching - I would recommend it.

I’ve been perusing through my logs lately and found the user agent “radianrss-1.0″ numerous times. I’d never heard of this program (maybe an RSS reader?), so I did a google search. The only commentary I found was this post speculating that 142.166.3.123 was possibly involved in the compromise of katester.net.

Interestingly enough, the rest of the search results are the traffic statistics pages of various Wordpress blogs around the Internet. There doesn’t seem to be a clear answer for what “radianrss” is, or why 142.166.3.122-123 is constantly indexing all of my blog posts.

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                       DD-WRT v23 SP2
                   http://www.dd-wrt.com

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I installed dd-wrt on my Linksys WRT54g because I was having problems with the Sveasoft Alchemy firmware. The wireless was dropping constantly, which can be real annoying when you’re trying to do a video call on Skype. My suspicion was that the firmware image was too large and too many services were trying to be run at once, and the unit was running out of memory.

Once long ago I had problems with the Alchemy firmware getting an IP address from my DSL connection. I managed to get syslog working (shouldn’t have been hard, but it didn’t work well with Alchemy) and the errors seemed to point to the fact that the unit was running out of memory. It would eventually work, it just took 20 minutes to get an IP address after it booted. Then it would stay up for months.

I guess I’ve just been out of the loop with regard to the newer firmwares. dd-wrt has much of the same basic functionality in their ‘mini’ version as the Sveasoft Alchemy fully featured version did. And to think that at point I paid for Alchemy because I wanted a more featureful, stable firmware

The wireless issues have gone away, and the web interface has a much more polished feel to it. I like logging into the router just to look at the interface and see the random stats. It also gives you status on the signal strength of the wireless clients, which can be very useful!

The dd-wrt firmware is famous for being able to do client mode bridging, i.e. act as a transparent wired-to-wireless bridge. I’m looking forward to trying that out some day.

By the way, although my unit will broadcast at a power of 251mW, I read on the dd-wrt wiki that 84mW is ideal for most hardware in terms of getting the best signal-to-noise ratio. At 84mW, I get a SNR of somewhere between 30-40, so I feel like that is probably pretty accurate information, considering I probably only need a SNR of 10-15 to get a very good wireless signal.

Try out dd-wrt today!

There are two major reasons (I know of) that can cause extremely slow SSH logins - anywhere in the range of 15-30 seconds. It doesn’t seem like a long time, but it takes forever to wait that out sitting at the terminal.

Say no to GSSAPIAuthentication

For some reason, GSSAPIAuthentication is turned on by default in Ubuntu Feisty (7.04). If you ssh -v somewhere.com, you’ll see this in the output:

...
debug1: Local version string SSH-2.0-OpenSSH_4.3p2 Debian-8ubuntu1
debug1: An invalid name was supplied
Cannot determine realm for numeric host address

debug1: An invalid name was supplied
A parameter was malformed
Validation error

debug1: An invalid name was supplied
Cannot determine realm for numeric host address

debug1: An invalid name was supplied
A parameter was malformed
Validation error

debug1: SSH2_MSG_KEXINIT sent
...

There are two ways to fix it. You can edit either /etc/ssh/ssh_config to include

GSSAPIAuthentication no

Or, you can edit ~/.ssh/config and add the same line. The only difference is that /etc/ssh/ssh_config will affect all systems users - probably a good thing.

Slow/broken DNS lookups

Each time you log into an OpenSSH server, it will typically perform a reverse-lookup on your IP address and store it in wtmp (try running the command “last”). If that DNS lookup times out, you’ll be in for a big delay. Whats worse, OpenSSH has a habit of performing the lookup 3 or 4 times, further extending the delay to 30 seconds or more.

Its generally best to fix the source of the problem by fixing whatever problem exists in your DNS infrastructure. This could be as simple as pointing /etc/resolv.conf to the correct nameserver.

If you’re really in a bind, you can pass the -u0 flag to sshd. Unfortunately, the sshd man page does not reveal any config file options to accomplish the same thing. But, the -u0 flag will stop sshd from performing any lookups that are not absolutely necessary as part of the authentication mechanism.

If you want to share a PDF of a web page or any other document with another person, PDF is usually the way to go. There are free PDF printers out there for Windows, but fortunately the necessary software is probably already installed on your Linux distribution. Just use ps2pdf.

First, print from your application (ie. Firefox) and make sure to check “Print to file”:

Press Print, save the file as filename.ps , and then run the following command:

$ ps2pdf filename.ps

The resulting file will be filename.pdf.

This is also a good way to convert old PS files (which can get pretty large) to the smaller PDF format. And, if for some reason you want to go the other direction, you can always use the pdf2ps utility.

Its long been known that you can use something like the User Agent Switcher to make it appear like you’re using a different operating system than you really are. This can be useful on some websites that insist you need to run Windows - when in fact Linux or practically any other operating system will work fine.

But for those sites that are actually telling the truth, you can often run Firefox under WINE with very good results. Just head over to www.getfirefox.com and download the Windows binary. The site actually does its own OS detection, so you’ll probably want to choose “Other Systems and Languages.” Once you have it, make sure you have WINE installed. I also installed the MS truetype fonts because it looks terrible otherwise.

# apt-get install wine msttcorefonts

And then start the installer

$ wine Firefox\ Setup\ 2.0.0.7.exe

You’ll go through the normal install process, and when you’re finished you’ll see a new Firefox icon on your Linux desktop:

Double-click it and you should be good to go! If you want to visit a site with audio, you’ll want to run winecfg, visit the Audio tab, choose your settings (I just left the defaults) and click Apply. Otherwise you might run into some issues with Firefox crashing. If its any consolation, Firefox will crash on certain sites powered by Move Networks in Windows, too, if there is no audio driver installed. This is probably related to the Firefox extension you must install to view the site.

I recently wrote about the cron job that I run to keep my Debian and Debian-like servers up to date automatically.

It turns out that apt-get (or libapt, more specifically) has a mechanism to automatically download and install security updates. This will work across package management applications (apt-get, synaptic, aptitude, etc) and is very simple to setup. Edit /etc/apt/apt.conf.d/10periodic to include the following:

APT::Periodic::Update-Package-Lists "1";
APT::Periodic::Download-Upgradeable-Packages "1";
APT::Periodic::AutocleanInterval "0";
APT::Periodic::Unattended-Upgrade "1";

Your distribution should already have a cron job (usually in /etc/cron.daily/apt) that runs every day and updates as per these configuration options. To see the entire config, run

$ apt-config dump

For those interested, this configuration setting is what Synaptic sets when using its “Install security updates without confirmation” option.

Thanks to g for pointing this out.

If you didn’t already know, Ubuntu 7.10 Gutsy Gibbon will be coming soon!

Maybe I’ll finally get suspend support for my dual core Dell XPS desktop?

Any guesses if the Ruby and Rails packaging will be any better?

So I ran into the strangest thing today. Vim complains because I tried to use ’syntax enable’ in my .vimrc.

$ vim myfile.rb
Error detected while processing /home/solipsistic/.vimrc:
line    1:
E319: Sorry, the command is not available in this version: syntax enable
Press ENTER or type command to continue

Apparently Debian-like distributions don’t package the full version of vim by default. They pack a ‘lite’ version.

# apt-get install vim

And you’ll be rolling again.