OT: Audacity noise removal question

For security reasons, you don't want to be logged in as root all the time.

Opensuse is well known for working well next to windows, so I use it in dual boot as well as the primary OS. I need to think if it ever wiped out my binaries. I don't believe updates touch user/local/bin. If you put a binary where the OS puts them, then I suspect all bets are off. But that is a problem in many OSs, including windows. If the windows program doesn't have an installer, I put the binary in a bin directory which I have added to the path.

The real problem with opensuse is the library locations. I often find myself having to set parameters so that libraries can be found, or creating symbolic links to make them appear in the right place.

I've also found opensuse a bit buggy with gnome. It works fine with KDE.

Hopefully the filtered audio was saved in wave format. I had mentioned that when you started this journey. If you saved it as mp3, then you doubly compressed it, hence the dreaded cascade of codecs.

Memory is so cheap these days, I do all recording in wave. You want to compress only once.

Sox is a handy tool. I've used it to take sampled audio and create a PWL input deck for spice to evaluate comm circuitry. It took minimal programming to get it from sox to spice.

Sox is multiplaform and not very hard to use. It is a default install in linux.

There is a lot of good software that is strictly command line. I don't blame the programmers for doing this since gui programming is just plain annoying busywork. It is far more interesting to code algorithms than deal with buttons.

Some command line programs are so good that another programmer writes the gui just so the great unwashed can use it. Exiftool for example.

The deal with command line and scripting is all the control data is presented at once. With gui, you never know how the user will enter data. It is a time sink to cover all bases.

Incidentally, the greatest command line program of all time is probably dd. Very powerful, and in the wrong hands, very destructive.

The final step in any audacity processing is to normalize.

On a sunny day (Sat, 24 Mar 2012 18:44:01 -0700) it happened miso wrote in :

And dvdauthor.

There is also siggen-2.3.10, it has an utility called 'sweepgen' That pops up a small curses sweep generator in the xterm or rxvt. You can set sweep range, and output the signal on one channel, an set the sweeping speed, sweeping waveform, and output that on the other channel and use that a scope X trace, if you use it as input to a filter or amp, then you can see the frequency characteristic just like that, Say sweep from 10 Hz, to 14 kHz, at 10 Hz, with triangle or sine wave, you can just check your audio filters or equalisers or whatever. It is audio range only, via the soundcard, but those little command line utilities are very nice to have.

On a sunny day (Sat, 24 Mar 2012 18:24:54 -0700) it happened miso wrote in :

I have heard that song many times, and, at least to me, it makes no sense.

There are different cases, for many years, > 4, I had several servers online 24/7, http, ftp, mail, named, etc. Of course Apache runs as some user. But there is no reason why "*I*, or say the system administrator should not be logged in as root. What are you going to do to me? Nothing, try it.

That is one aspect, then there is the 'protection from your own mistake' fable. Put it this way, after running as user 'dummy' with zero permissions to do anything usefull,, they get so used to typing sudo this_or_that, that the word 'sudo' becomes their command prompt. Ok, wait, sudo rm -rf /* Oops why does that take so long? Oh I meant sudo rm ~/*, oops, I actually meant rm ~/*

And the third issue is, that they, if they never even use sudo, so basically just use the peesee as a scratchpad, then the one time they need to be root they are so unexperienced and spaced out that they really cause big damage to the system, and then also do not know how to fix it.

In an environment where others can have access to your root terminal I agree, use ctrl D, log out if you leave the keyboard. But a bad guy will have no problem pulling the powerplug...

They should not, but mine did.

Dunno what you mean by that, OS does not put binaries anywhere,

Until this day it seems there is no agreement if things should go in /usr/local/.... or /usr/...

Sometimes one is in the path first, then the other. Cost me a lot of time to make links and delete old versions, on top of that the version system of different distros then often interfere. I prefer /usr/local/.., but watch out, some 'make install' may dump it in /usr/.. or even in /opt or worse in /usr/share I have seen it all.

I have installed (compiled from source the old fvwm (not version 2) and xfm file manager, I have 9 virtual screens, one with xfm and some icons, all others carry rxvt. Programs I use often are under key sequencies (xmodmap, xbindkeys), and all the rest I just type. I have a thousand scripts too, those do the heavy works. That means you only have to find a solution once, not like that GUI stuff every time again. Still Linux has become top-heavy, and money making oriented enterprises like RatHead, Suse in bed with Microshot, just love to add their incompatible stuff as 'customer binding' and then have you pay for support because it wont work. Maybe QNX? Maybe open BSD? I really want to try that sometimes, but already disk is full again...

On a sunny day (Sat, 24 Mar 2012 18:48:26 -0700) it happened miso wrote in :

Yes, use it all the time, to cut some point in a long HD .ts dd if=movie.ts bs=1000000 skip=150000 | mplayer -

I have an old version of mplayer that I modified to show the input byte count, makes it easier to cut larger satellite files.

More dangerous is: [sudo] deedee if=/dev/urandom bs=1000000 count=1 > /dev/sda

I have modified dd to deedee just out of compassion for the cut and paste crowd that wants to try it :-) BTW if anybody want to try it, it also works with /dev/zero as input.

On a sunny day (Sat, 24 Mar 2012 15:05:22 -0700) it happened Joerg wrote in :

my xpequ has an AGC option.

But simpler, 'sox' has the 'norm' option that normalises a wave file for amplitude.

To quote: --norm Automatically invoke the gain effect to guard against clipping and to normalise the audio. E.g. sox --norm infile -b 16 outfile rate 44100 dither -s is shorthand for sox infile -b 16 outfile gain -h rate 44100 gain -nh dither -s See also -V, -G, and the gain effect.

Please read man sox and look for gain, typing /gain will highlight that word everywhere in the manual

It may teach you some things about audio too.

On a sunny day (Sat, 24 Mar 2012 14:27:09 -0700) it happened Joerg wrote in :

You already wasted one CD. Having a CD-RW around pays itself back many times, I use them, I make mistakes. Especially with DVD menus and buttons... Try before you have many coasters.

Irrelevant for an audio CD.

-- "For a successful technology, reality must take precedence over public relations, for nature cannot be fooled." (Richard Feynman)

Some older CD players don't like some phtalocyanine CDs. You need to pick good name brand ones. I find Memorex OK.

I use Mapivi. Written in perl. Very comprehensive.

Jeez. Upscaling DVD players are less than $75 these days, and they all play CDs and do so likely better than any CD player for the same money.

Multiple media benefits. Mainly that they are not picky about base media type.

This Luddite Joerg idiot is probably still using an original Sony CD player.

On a sunny day (Sun, 25 Mar 2012 09:28:20 -0700) it happened Fred Abse wrote in :

Right :-)

He has no control over what the disks will be played on. Maybe ten year old car players, or worse.

Nothing to do with whatever Joerg himself uses.

They are for members of his Church, which you should know already, if you've been following the thread.

Yep, I store in Audacity format and at the end WAV.

I think I'll live.

Easy to say if you leave in or near an urban environment. Out here it's not a problem to buy horse feed of glow plugs for the tractor. But CD-RW, wots dat? :-)

Maybe I find a CD-RW somewhere. But not today.

Suggest to read the whole thread before making such unqualified remarks.

Actually they are people in the midwest who could not fly in for the service, due to advanced age and subsequent health issues. And right, I do not know what players they have, I don't even know them personally. The widow knows them.