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March madness HDTV is my desktop background in Ubuntu Gusty. What's yours? March 16th, 2008

The purpose of this post is for me to contribute all the useful information I've gathered on HDTV recording and playback over the last year on NVIDIA+Ubuntu platform.

First off, I'd like to say that not enough linux tutorials are specific enough about hardware branding. If you have hardware that works well out of the box, be loud about it! Plenty of people are out there looking for good linux compatible hardware and even a random blog post can help someone make the right hardware decision.

Hardware:

To playback/record HDTV in Linux, you gotta have the right hardware. You need an NVIDIA graphics card for great compiz-fusion compatibility and a chance at XvMC (that's short for X-Video Motion Compensation). You also need a pcHDTV 5500 tuner card from these guys. Now, it's important to note, I'm talking about broadcast HDTV here (not cable, because I don't have it).

Software:

Pre-requirements

sudo apt-get install subversion cvs build-essential xserver-xorg-dev dvb-utils

MPlayer

sudo apt-get install mplayer

www.mplayerhq.hu

Linux Kernel > 2.6.18 (Don't worry Ubuntu's got this covered)
NVIDIA graphics driver (Install this from restricted drivers if you haven't already)
XvMC configuration may be required. You have to make sure you have the right library's name in this file: /etc/X11/XvMCConfig
You can see my XvMCConfig file below --

$ cat /etc/X11/XvMCConfig
libXvMCNVIDIA.so.1
$ ls -l /usr/lib/libXvMC*
lrwxrwxrwx 1 root root     25 2007-11-23 22:46 /usr/lib/libXvMCNVIDIA.so.1 -> libXvMCNVIDIA.so.1.0.9639
...

If the filename in XvMCConfig does NOT match the NVIDIA library in /usr/lib you must change the config to MATCH!
Xwinwrap from en.opensuse.org.

cvs -d :pserver:anoncvs@cvs.freedesktop.org:/cvs/xapps co xwinwrap
cd xwinwrap
make

mplayer-drb-server.rb from rubyonlinux.org

svn co http://svn.rubyonlinux.org/mplayerctl

Using the tools for recording HDTV:

You can skip to the playback section if you are only interested in HDTV playback
First off, you need to configure the TV channels using dvb-utils scan.

mkdir ~/.azap
scan -a /dev/dvb/adapter0 > ~/.azap/channels.conf

If that went well you are ready to start recording! I realized that recording from one of these capture cards is extremely easy once you have it setup with dvb-utils. The command "azap -r CHANNEL_ID" tunes to that channel. Then all you have to do is read from the device. I started off using the UNIX command 'cat' to do this. However, the card drivers would hiccup every once in a while and cause cat to crash. This was the birth of chan-record.rb in March 2007, a simple program to handle crash recovery during recording. Since then it has evolved into a recording scheduler and tuner as well.
To use chan-record.rb (part of the mplayerctl checkout), you will need ruby + rubygems + chronic (a gem).

Using the tools for playback of HDTV

mplayer-drb-server.rb does not require anything except for ruby + mplayer + linux to run
I've coded in some defaults for mplayer options that use xwinwrap -or- xvmc (don't try to use both at once). The default is to let mplayer choose automatically
Here's examples of how to use it

mplayer-drb-server.rb -f livetv.ts -x /home/user/xwinwrap/xwinwrap

mplayer-drb-server.rb -f livetv.ts -n

The cool thing is that mplayer-drb-server.rb can be controlled via a network connection and simple ruby utilities. See the commands 'pause.rb' and 'seek.rb'. Of course, if MPlayer is in the foreground (not using xwinwrap) it's simple to control it with normal keys and mouse.

pause.rb  -> pauses
seek.rb +30 -> seeks 30 seconds forward

Hope you enjoy!

Thanks for checking this out. It's a work in progress but could be very useful to someone who's a linux video geek like myself. Leave a comment!

3 comments »

Using DRb and ruby to control mplayer and record/playback HDTV. March 14th, 2007

I wanted HDTV broadcast in Ubuntu, so I bought a PC-HDTV 5500 tuner. It needs a 2.6.18 or higher kernel to work.

I’ve been working on some scripts to control my TV. So far I have a rudimentary server and client along with a HDTV record script that uses a direct copy from the device using the linux tool ‘cat’. My system @kernel 2.6.19 had a bug which causes cat to overflow.. So there is error detection and resume recording after a crash.

I’ll be using linux CRON to schedule recordings.

It is a work in progress. Here is the SVN repository: http://svn.rubyonlinux.org/mplayerctl/

I used Kazuki Takemura’s code to control mplayer, and extended it to use DRb connections.

Go ahead and comment if you are interested in helping with the project. I want it to become a simpler MythTV style thing eventually.. SIMPLER is better.

New commits, March 2008. Rudimentary recording and scheduling via cron are now possible. Need to improve the actual mplayer part now but it’s working so that’s great.

0 comments »

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