Electrowonder's blog

Surround sound activation for Mplayer, Ubuntu

2009-10-18T21:37:00.002+05:30

Mplayer has enough configuration arguments to initiate surround sound from stereo audio. One of my earlier posts was on how to activate the subwoofer channel. Now here is the full configuration

$ gmplayer -ao alsa -af surround=10,sub=75:5,center=4 -channels 5

Here
surround=10 : specifies the delay in surround channels (here it is 10)

center=4 : Which channel to redirect center channel audio derived from the front channels.

Mplayer will then derive the rest of the channels from the front channels and we have 5.1 music.

A Website for Under the hood info on cars

2009-09-11T21:41:00.003+05:30

I stumbled upon a site on the internet while searching for detailed information on car suspension and wheel alignment. Very lucidly presented information on cars and its maintenance is available on this site.

http://www.carbibles.com/

Activate subwoofer channel

2009-07-16T18:14:00.003+05:30

Even if any music player like mplayer is used to activate the subwoofer channel, It won't get activated until 6 channel mode is activated in the volume control dialog.

To do this first double click the volume control icon on the top panel.

On the volume control dialog check if an "options" tab is available.

If not then click the "preferences" button and tick the "options" check box to activate it.

Now in the "options" tab change "Channel Mode" to 6 channel.

My sound driver & Mixer is ALSA for nVidia.

Installing HP Printer in Ubuntu

2009-06-27T22:11:00.006+05:30

There is an easy way to install a HP printer in any Linux installation including Ubuntu. Thanks
to HP for providing an installer that does all the job on its own.

My printer is an HP Deskjet D2360. First goto the site -

http://hplipopensource.com/hplip-web/install_wizard/index.html

Then select Distribution, Version, Printer type and Model

Proceed to download the installer and move it into a folder. ( A separate folder)

The downloaded file will be something like hp[version].run. Start a terminal window and
access this folder then run the installer by typing

$sh hp[version].run

If you don't put the installer in a separate folder the default directory will be flooded with
installation files.

The installer itself will recommend you to run the installation as default user. Provide the
administrator/root user password when you are asked to.

Select automatic installation(Recommended by default). Proceed to answer some simple
questions and the installer will automatically download and install any dependancies if
required.

Then it will ask you to replug the printer and the installation is done. You can print a test page
if needed.

The HP download page also contains detailed instructions to run the installer.

CUPS Server not running

2009-06-26T17:56:00.007+05:30

To install a printer in ubuntu, the installer program demanded that the CUPS - Common Unix Printing System had to be be operational. But my system showed that CUPS was not active.

Then I verified System>Administration>Boot-up Manager and I couldn't restart CUPS

Typying cupsd at the terminal to evoke the daemon, I got the message -

"Child exited with status 1!"

A bit of googling told me to check /var/log/cups/error_log and it gave -

"/etc/cups/ssl/server.crt" is a bad symlink - No such file or directory

I found the solution later on as -

sudo apt-get install --reistall ssl-cert

It worked and CUPS was running again.

Making subwoofer work for mp3 playback in Ubuntu

2009-05-30T21:38:00.010+05:30

The only thing I felt missing whenever I played MP3s on Ubuntu was the rich punch of bass from my subwoofer speakers. There is no option of a mixer to reroute sub base frequencies to the subwoofer channel.

My Subwoofer is a home brewn one and has no external hardware to downmix and filter out the frequencies from the front stereo channels as found in 2.1 speaker systems. The ac3 filter or the ffdshow audio decoder I normally use in windows has this option but not in linux.

So I tried many media player applications in ubuntu. Amarok, Xine..etc...and ended up clueless

Then I installed mplayer from the repositories using

$ sudo apt-get install mplayer

MPlayer is a command line media player for KDE. The GUI version is GMplayer.

This one has got tons of command line options with it. The one I like particularly is the -af (Audio filter) option.

The man pages of mplayer are too large to scroll through, better make it into a file to be read by some thing like gedit.

it has the option sub=cutoff:channel

which it says will filter frequencies from the left and right channels using butterworth filter below the cutoff value and reroute it to the channel specified.

Here is what i have used

$ mplayer -ao oss -af sub=75:5 -channels 5

-ao : specifies the audio output driver, Here oss is given

-af : audio filter options without which the sub option won't work

sub=75:5 : the cutoff frequency and the sub channel

-channels : specifies the number of channels to be used.

Here mplayer recognises channel 5 as the sub channel.

if you want to invoke all these options when double clicking an MP3 file,

feed all these options with the "open with" menu's extra options. Add an "&" at

the end to make it work in the background.

Enjoy the thump of music!!!!

To configure the mixer for 6 channel mode in Ubuntu..see this post...

http://electrowonder.blogspot.com/2009/07/activate-subwoofer-channel.html

Solve APIC problem in Linux

2009-05-10T21:58:00.007+05:30

My AMD Athlon system used to freeze at boot time stating an APIC problem. We can temporarily skip the issue by adding noapic at the end of the boot command line.

But the problem keeps on nagging at each startup.

To solve the issue permanently edit the GRUB bootloader configuration file - menu.lst

$ sudo gedit /boot/grub/menu.lst

Scroll down to find some text similar to the ones we see at the bootup options. Here is one

title Ubuntu 8.10, kernel 2.6.27-9-generic
uuid d727a8ef-4fbe-457d-987c-6959924f76b6
kernel /boot/vmlinuz-2.6.27-9-generic root=UUID=d727a8ef-4fbe-457d-987c-6959924f76b6 ro quiet splash vga=792
initrd /boot/initrd.img-2.6.27-9-generic
quiet

Like wise we'll see many options below this one. Now we have to just add the word 'noapic'
at the end of the line "kernel".

Save the file & restart the system.

Simple way to get rid of USB flash Drive Viruses & Worms

2009-04-01T15:37:00.000+05:30

When it comes to the case of USB flash drives, some Anti-Virus softwares won't detect Worms or Viruses. U can get rid of them by a simple technique.

First ensure that the system you are using is virus free.

Before inserting your flash drive to the USB port, press and hold down the "SHIFT" key on your keyboard. Release the key only after 5 seconds. This will prevent the system from executing an autorun operation. Virues inside the drive get activated on these autorun events. DO NOT open the drive now in any way.

Then switch to WINRAR.Winrar provides a file browsing facility and is found almost in every PC. You can use any third party file browsing software. The viruses are made only to fool the Windows explorer. I have done this with ACDSEE's file browser too.

1) With Winrar, click the location dropdown bar to select the removable drive.

2) Here you can see the "autorun.inf" file which is primarily responsible for virus activation

3) Open the autorun.inf file by double-clicking it. It won't do any harm

The file says- Open 2fiji.com. There that's the one. Now we've to get rid of em. Close notepad

4) Press delete key on the keyboard after selecting the two files- The autorun.inf file and the other file mentioned in it

Thats it . Done. Now unplug the flash drive and insert it again. The drive is now ok and you can browse it using windows explorer.

Note that the name of the virus file may not be always 2fiji.com. Also it may not appear on the drive directly. It may be hidden inside folders and their subfolders. Also the filenames may have an extension of ".exe". and its name and icon might resemble that of a folder.

Watch Movies with a Laptop and TV - S-Video to Composite Converter

2009-02-14T07:28:00.001+05:30

A couple of months earlier, my tutor Mr.Shafeek rang me and asked how he could connect his laptop onto his television so he could watch movies on his big screen. He had brought a locally available "S-Video to RC cable" for 300 Rs and the thing didn't work. I assured him that I would find a solution and report to him at the earliest.

At the same time I was hunting for a circuit to convert VGA signals to composite video so that I could see my desktop on my TV screen. So I Googled it and came up with a simple, low cost solution to do S-Video to CVS(Composite Video Signal). I discussed this with my friend Arun.K.V and he too expressed interest with this small project for he was also tired of watching movies on his laptop LCD display.

Teaming up with him we first went to our local electronics market- Thakarapparambu road - where there are plenty of shops selling electronic components. To our dismay, all the shops offered an S-Video to RCA cable which costs between 100 to 500 Rs depending on the quality. When inquired, a salesman asked "You want S-Video to 2 RC or 3 RC???". We were dumfounded for a TV had only one CVS- RCA socket and the rest two were intended for stereo audio channels.

So we purchased an S-Video plug, an RCA plug, wires and a 470 pf capacitor (pretty small circuit). Again this costs between 60-100 Rs depending on the quality. Putting together everything according to the circuit diagram, the assembled cable worked fine and we saw a very lively, bright display of the desktop on the 21-inch TV screen. Laptops with S-video ports also have configuration menus to adjust the display on the TV.

Presenting the cable to Mr. Shafeek sir, it is needless to say he was delighted. A DivX movie played on the TV screen resembled DVD like video quality.

The same site which I googled up also had the circuit I was looking for - a VGA to CVS converter. As convertion to CVS involves generation of timing signals the circuit is a bit complex, but can be built.

Here is the page for the S-Video to CVS conveter: http://www.epanorama.net/circuits/svideo2cvideo.html

VGA to PAL and NTSC: http://www.epanorama.net/circuits/vga2tv/vga2palntsc.html

Chrome-A New Browsing Experience

2009-01-17T18:08:00.000+05:30

Google recently released its own browser named "Chrome". This one application is so tailored that it became popular within no time. Being part of an open source project too, Chrome is still under development and only the Beta version is available for download.

This browser is so fast-it loads in seconds and is less memory hungry. Chrome having excellent features like auto complete, predictive search, thumbnails of frequently visited web pages makes it the application for the regular net surfer.

If you haven't tried Chrome yet, give it a try- It weighs only about 8 MB

Download Chrome

Features at a Glance

Very short loading time - Activates within seconds
Tabbed browsing facility for easier browsing
Requires less memory
Provides thumbnails of frequently visited pages at the welcome screen
Provides protection against malicious websites
Updates itself without user intervention
Its freeware - feel free to use

Expecting more from Google. Stay tuned.

Links for more information:

http://www.google.com/chrome/intl/en/features.html

http://en.wikipedia.org/wiki/Google_Chrome

http://en.wikipedia.org/wiki/Comparison_of_web_browsers

To the Four abodes of Lord Ayyappa

2008-10-09T07:58:00.000+05:30

Being a theist, I like to kickstart good things with the name of the Lord Almighty. I'm not being superstitious but I have the belief that it will make me do virtues.

Think of Lord Ayyappa, and the only name that rushes into everyones' mind is Sabarimala. I have astonishingly discovered that many people in kerala do not even know about the other three (important) temples that have Lord Ayyappa as the diety. The other abodes are

Kulathupuzha, Aryankavu and Achankovil.

All the four temples lie in the southern part of Kerala-The land of lakes, paddy fields, rivers mountains, forests- everything to call it the "God's Own Country". And all these temples lie at the foothills of the Western Ghats. One can visit all these temples in one day. But only according to a pre-planned schedule. The reason being the long hill climb at Sabarimala which takes hours.

I'll start with the speciality of each temple. Even if Lord Ayyappa was brought up at Pandalam, these places deserve special importance in the life of Ayyappan. He has exhibited miracles many a time at these places.

In Kulathupuzha, he is worshipped in the form of a little boy. In Aryankavu he resides as a teenager warrior, In Achankoil he is with his two wives (Purna & Pushkala) and at Sabarimala as a Sanyasin.

When I start from my home town Thiruvananthapuram, I advance North-West along Nedumancaud, Palode route. The first stop would be Kulathupuzha and is by the side of the main road. It lies to the right side as we go North, and one has to cross a narrow bridge across the river. Ladies are allowed here from the ages 10-60. One of the main offerings here is to feed the fishes in the river. It is said that Ayyappan considers them as his children.

Now continuing the journey North, we'll pass through the Thenmala Eco Tourism area. The road actually leads to the NH 208 connecting Kollam City with Thirunelveli City. Take a right from Thenmala to advance towards Aryankavu.

Just before the Kerala-Tamilnadu border we'll find Aryankavu Temple entrance by the right side of the road. Decend the steps to the temple. Ladies of ages 10-60 are not allowed inside. As I said, Ayyappa resides here as a teenager armed with weapons. A young warrior who exhibited his capabilites which were way ahead in his age.

Now the journey to Achan kovil is not a straight path. There are two routes- One starting from "Shenkottai" in Tamilnadu and another from "Aalimukku" near Punalur. The latter takes us through private plantations and the road is not fine most of the year round. The former one is maintained up to a Kerala-Tamilnadu check post by the TN government. Choosing the former one is better to save time and the automotive suspension.

On the way, we'll encounter 11 hairpin bends...6 uphill and 5 downhill after passing through a tamil agricultural village. The road is much narrow and only wide enough for a bus to pass through. On the way there is a place known as Kottaivasal. An idol of Lord Ganesha is kept there and travellers won't forget to give offerings at the temple while climbing uphill.

As I mentioned earlier, the diety is in the form of Dharma Sasthaavu, who resides there as a king with two wives. The history of this temple dates back centuries. Numerous stories are associated with this temple. The group of small temples that we find opposite to the Sastha temple are loyal disciples of sashtavu and all the dieties found there are linked to Sasthavu in some way. A detailed description of this temple and the stories linked with it are given in the book "Iytheehyamaala" by Kottaarathil Shangunni.

If we want to proceed further towards Sabarimala from this point, we should take the road to Punalur which takes us through some private plantation roads. Then we can advance towards Sabarimala.

Sabarimala, being a major piligrim center in Kerala, is much important to the Kerala Govt. too. Therefore the roads to Sabarimala are always fine. The temple has to open on the 1st day of every malayalam month. One can reach up to pampa by wheels. Then from the base point we start climbing up hill and walk the 4 km journey upto sannidhanam bare foot. The 4 hills we need to climb are karimala, neelimala, appachimedu and saramkuthi. The path through saramkuthi is used only during season time. The rest of the time piligrims use an alternate path built by Subramaniam Trust for carrying construcion materials and other goods by tractor upto sannidhanam.

There are 18 steps to climb upto the temple. At the top we find the diety Lord ayyappa in his sanyasin form. Down below the steps we find a "Vavar nada" where Vavar- a king who was an Islam and a very close friend of Lord Ayyappa. There is also a Vavar Mosque at Erumeli- another place from which devotees start up hill climb. In all the ayyappa temples we find Karuppswami who was a friend of Lord Ayyappa and Karuppayi amma his consort.

Festivity time in Sabarimala is during November-January. It is in January when Maraka vilakku and Makara samkramana pooja are conduted.

I have heard about a fifth important Ayyappa temple "Kanthamala". But I'm not aware of its existence or location.