Friday, May 30, 2008

DVD Issues

Well, I just purchased a Philips DVP5990 DVD player last weekend. It has some nice features, including the ability to play DIVX movies from an external USB drive.

I spent the past 2 hours trying to connect the player to my TV through HDMI. I tried 3 different cables, all of which gave me a horrible picture that looked like something out of an old four color CGA monitor from the 1980s. I tried upgrading the firmware, jiggling the wires and changing settings all to no avail. Finally, one step away from returning the player for a replacement, I tried unplugging the unit for a few minutes. After turning it back on, all of the color problems have disappeared. The player appears to be functioning normally. Apparently, not even a reboot after upgrading the firmware was sufficient to fix this bug...

Friday, May 09, 2008

Compressed Time

I've been having trouble with VMWare guests losing clock ticks to the extent that the guest OS clock runs approximately half-speed compared to the host. This is with an Ubuntu Server host OS and a Debian Etch guest OS. I found that adding these settings to /etc/vmware/config:

tools.timeSync = "TRUE"
host.useFastClock = "FALSE"
monitor_control.virtual_rdtsc = "FALSE"

Fixed the timing issues as well as the boundless supply of timing errors showing up on the host in /var/log/messages:

rtc: lost some interrupts at 512Hz.

Thanks to the following for inspiration:

http://jackshck.livejournal.com/117486.html

Thursday, March 27, 2008

misunderstandings

This is a wonderfully written statement:

http://my.barackobama.com/page/community/post/hopewagner/gGBRVV

What is it about human nature that inspires us to pass judgment expediently and without regard for consequences? I wonder if anyone anywhere can claim that no 20 second sound byte over the span of their entire life could be construed as offensive, particularly when taken out of context?

Wednesday, March 19, 2008

addendum

I'd just like to go on record saying that I vote democrat, but if Hilary somehow steals the nomination from Obama, I will be voting for Ralf Nader or none-of-the-above :(

negativity

The conservative movement in this nation never ceases to amaze me. One of the most remarkable speeches of the 21st century was delivered yesterday and it fell upon many deaf ears. What is it about fear that a near majority of people in this country find it so enticing? It is the same fear that allowed popular opinion to sway toward the lies of our fearless president, whose trillion dollar mistake is commemorated today. "The troop surge is working." You have nothing to fear. Except black ministers...

Thursday, February 07, 2008

Invalid Checksums

Apparently, there is a checksum offload engine in my laptop's network card. Unfortunately, this engine doesnt work, at least with the latest Ubuntu release (Gutsy).

The problem manifests itself as a continuous stream of bad UDP checksum errors when monitoring network traffic with Wireshark. In particular, every DNS request my system sent had an invalid checksum error. I did not bother to check for the same problem with other traffic types. In any case, I found a bug report describing this exact issue:

https://bugs.launchpad.net/ubuntu/+source/libpcap/+bug/31273

Apparently it is very easy to turn off the checksum offload feature using this command:

sudo ethtool -K eth0 rx off tx off

After this modification, my packets are no longer broken!

Thursday, January 10, 2008

Linux and the HVR 950

Just purchased a Hauppauge WinTV-HVR-950, which is essentially a small USB device that acts as an analog / digital television tuner. Not only can one tune into new digital over-the-air broadcasts, but also HD programming as well. Using a home-made DB2 antenna, I am able to pull in 31 digital channels including 6 HD channels. This was a very pleasant surprise :)

My ultimate goal is to connect this tuner to my PC and the PC to my old HD television so that I can get over-the-air digital channels and rid myself of cable. I attempted to get the tuner working with Ubuntu 7.10 (Gutsy) using this guide ( http://lunapark6.com/usb-hdtv-tuner-stick-for-windows-linux-hauppauge-wintv-hvr-950.html)

This guide ( http://parker1.co.uk/mythtv_ubuntu.php) was also helpful in my attempt to set up MythTV. Unfortunately, I did not succeed in getting the software to work. I may try again at a future date. I was able to get the tuner to work with a few simple command line utilities though. I installed the following packages in Ubuntu:

dvb-utils, dvbsnoop, dvbstream, dvbtune

These utilities allowed me to scan all digital channels identified by the receiver. The scan takes a few minutes, so be patient. Also look at the other example scan files in the dvb-utils directory. Another may be more directly applicable, depending upon your location and interests.

sudo /usr/bin/scan /usr/share/doc/dvb-utils/examples/scan/atsc/us-ATSC-center-frequencies-8VSB > channels

This gives output like the following to a file called channels:

WBFF-HD:665028615:8VSB:49:52:3
Good TV:665028615:8VSB:65:68:4

Dont be surprised if you get allot of output on the command line...it complained about every unavailable channel for me. The information above includes the name of the channel, frequency, and encoding. To tell the tuner to tune into a channel, use a command like the following:

azap -r -c channels "Good TV"

Note that we are using 'azap' (for ATSC digital programming). See http://www.linuxtv.org/wiki/index.php/Zap for more information.

Finally, the following command will stream the output of the tuner directly to mplayer for display on the screen:

mplayer /dev/dvb/adapter0/dvr0 -cache 8192 -framedrop -vo x11

I have successfully tuned into standard and HD digital broadcasts using this simple technique.