Tuesday, May 29, 2012

extracting audio from DVD

The older post on this topic mentioned DVD Decrypter and others. This time, for some reason, that method did not work. Perhaps because of some mistake in the sequence of steps, I suppose, the resulting file was a VOB file and not an mp2 file. Anyway, the file was not being opened by any of the AC3 decoding methods like WinAmp plugin etc.

So, this time, I tried just copied the VOB files to the hard disk and opening them with VirtualDubMod, extracting the audio stream using Streams -> Stream List -> Save wav. That wav was opened using Soundforge, using AC3 codec. Slightly buggy, since each VOB file's wav data had the duration info of the entire program chain, and so had some sort of repeating audio after the first 25 minutes or so which had to be cut out. But otherwise OK.

Sunday, May 20, 2012

installing Perl module on dreamhost

K wanted me to include mp3 tags on the downloads at dl.radiosai.org. Googled installing Perl Module without root access, and found lots of people doing it, so went on to install MP3::Tag module without root access.

First I tried the procedure at
but the perl process kept getting killed as given at

Dreamhost recommends installing via the CPAN command, as given at
and then the process doesn't get killed.

But the wiki had some bugs. Got errors like

Cannot gzopen $ENV{HOME}/.cpan/sources/authors etc. Googled it and found
where the user k2S explains that he did two things differently from the wiki page
that is

**don't forget to add the suggested lines into your '~/.bash_profile' - that is, not ~/.profile
 ** test command 'echo $PERL5LIB', it should return the correct path

* *I had to edit also ~/.cpan/CPAN/MyConfig.pm and replace all '$ENV{HOME}' with the correct path

Once I did this, the install worked fine, with perl -MMP3::Tag -e 1 not returning any errors.
 (I had actually done the manual config of the MyConfig.pm  as given in the wiki, too.)

After the module installation, some trial scripts still gave errors. Trying out a basic script from

got errors like
Can't call method "get_tags" on an undefined value

Found this explanation, that it is because the file has no tag to begin with:

Then tried tagging the file with no tag to start with, and got errors like:
Can't call method "new_tag" on unblessed reference at ./mp3tagger.pl line 6.

Problem was - the filename has to have the full path, and not start with ~/
Once that was done, the script worked. Now to work out some sort of tagging scheme, after which the tagging can be done.

Friday, May 18, 2012

Cyberoam and ftps

The guys at the studio had some trouble connecting to secure ftp. Their newly commissioned server would accept connections only over secure FTP on port 21, as below,
I was able to connect from BSNL network as well as from the Planetarium. But when they tried from the studio, they were getting timed out at "Initializing TLS". I replied with the following:
When the connection is initialized, a dialog box pops up, talking about the certificate, and whether we want to accept the certificate - attached. Only after you say yes does it connect. So, there are several possibilities - either your machine is not getting the certificate due to cyberoam, or somewhere in settings you have set it to not ask, or deny the certificate.

My guess is cyberoam. Cyberoam is set to proxy ftp connections. So, ftps may need some settings. You may want to ask the cyberoam support about this.

"Cyberoam parses SSL handshake (SSLv2, SSLv3, and TLS) and extracts “Common Name” (CN) from the certificate. It applies control filters on common name. Based on the outcome of filters, user is either served the page or the connection is terminated."

So probably somewhere in cyberoam you will need to add the certificate of this server, saying accept this certificate. Only then, I am guessing, will cyberoam connect to the server....
They contacted cyberoam support, and as per their recommendation added a MASQ rule so that this connection goes directly instead of through cyberoam's transparent proxy. Then it worked fine.

Wednesday, May 16, 2012


A sent me this link,
for software which can create a portable subset of your desktop with the software you need, which you can then run from USB key or other portable storage on any Windows computer. Basically making any app portable. Interesting concept.

Wednesday, May 09, 2012

Google Sky Map

I remember seeing a device on Amazon.com which you could point to the sky, and it would label the objects seen. Now, an app - free to boot - does the same job. Google Sky Map.