Posts Tagged ‘interactivity’

Text mode (console) browsing with tabs with Elinks / Text browsers – (lynx, elinks, links and w3m) useful HTTP debugging tools for Linux and FreeBSD servers

Friday, April 27th, 2012

The last days, I'm starting to think the GUI use is making me brainless so I'm getting back to my old habits of using console.
I still remember with a grain of nostalgy how much more efficient I used to be when the way to interact with my computer was primary in text mode console.
Actually, I'm starting to get this idea the more new a software is the more inefficient it makes your use of computer, not to mention the hardware resources required by newer software is constantly increasing.

With this said, I started occasionally browsing again like in the old days by using links text browser.
In the old days I mostly used lynx and its more advanced "brother" text browser links.
The main difference between lynx and links is that lynx does not have any support for the terrible "javascript", whether links supports most of the Javascript ver 2.
Also links and has a midnight commander like pull down menus on the screen top, – handy for people who prefer some more interactivity.

In the past I remember I used also to browse graphically in normal consoles (ttys) with a hacked version of links calledTThere is also a variation of linksxlinks suitable for people who would like to have graphical browser in console (ttys).

I used xlinks quite heavily in the past, when I have slower computer P166Mhz with 64MB of memory 2.5 GB HDD (What a times boy what a times) .
Maybe when I have time I will install it on my PC and start using it again like in the old days to boost my computer use efficiency…
I remember the only major xlinks downside was it doesn't included support for Adobe flash (though this is due to the bad non-free software nature of Adobe lack of proper support for free software and not a failure of xlinks developers. Anyways for me this wasn't a big trouble since, ex Macromedia (Adobe) Flash support is not something essential for most of my work…

links2 is actually the naming of links version 2. elinks emerged later (if I remember correctly, as fork project of links).
elinks difference with links constitutes in this it supports tabbed browsing as well as colors (links browser displays results monochrome).

Having a tabbed browsing support in tty console is a great thing…
I personally belive text browsing if properly used can in many ways outbeat, graphic browsing in terms of performance and time spend to obtain data. I'm convinced text browsing is superior for two reasons:
1. with text there is way less elements to obstruct your attention.
– No graphical annoying flash banners, no annoying taking the attention pictures

2. Navigating in web pages using the keyboard is more efficient than mouse
– Using keyboard shorcuts is always quicker than mouse, generally keboard has always been a quicker way to access computer commands.

Another reason to use text browsing is, it is mostly the text part of a page that matters, most of the pages that provide images to better explain a topic are bloated (this is my personal view though, i'm sure designer guys will argue me :D).
Here is a screenshot of a my links text browser in action, I'm sorry the image is a bit unreadable, but after taking a screenshot of the console and resizing it with GIMP this is what I got …

Links text console browser screenshot with 2 tabs opened Debian GNU / Linux

For all those new to Linux who didn't tried text browsing yet and for those interested in computer history, I suggest you install and give a try to following text browsers:
 

  • lynx
  • (Supports colorful text console text browsing)
    lynx text console browser Debian Squeeze GNU / Linux Screenshot

  • links
  • Links www text console browser screenshot on Debian Linux

  • elinks
  • (Supports colors filled text browsing and tabs)
    elinks opened duckduckgo.com google alternative search engine in mlterm terminal Debian Linux

  • w3m
  • w3m one of the oldest text console browsers screenshot Debian Linux Squeeze 6.2

By the way having the 4 text browsers is very useful for debugging purposes for system administrators too, so in any case I think this 4 web browsers are absoutely required software for newly installed GNU / Linux or BSD* based servers.

For Debian and the derivatives Linux distributions, the 4 browsers are available as deb packages, so install them with following apt 1 liner:
 

debian:~# apt-get –yes install w3m elinks links lynx
….

FreeBSD users can install the browsers using, cmd:
 

freebsd# cd /usr/ports/www/w3mfreebsd# make install clean
….
freebsd# cd /usr/ports/www/elinksfreebsd# make install clean
….
freebsd# cd /usr/ports/www/linksfreebsd# make install clean
….
freebsd# cd /usr/ports/www/lynxfreebsd# make install clean
….

In links using the tabs functionality appeared, somewhere near the 2001 or 2000 (at least that was the first time I saw links with tabbed browsing enabled). My first time to saw links support opening multiple pages within the same screen under tabs was on Redhat Linux 9

Opening multiple pages in tabs in the text browser is done by pressing the t key and typing in the desired URL to open isnide.
For more than 2 tabs, again t has to be pressed and same procedure goes on and on.
It was pretty hard for me to figure out how I can do a text browsing with tabs, though I found a way to open new tabs it took me some 10 minutes in pondering how to switch between the new opened links browser tabs.

Hence, I thought it would be helpful to mention here how tabs can be switched in links text browser. Actually it turned it is pretty easy to Switch tabs tabs back and foward.

1 tab to move backwards is done with < (key), wheter switching one tab forward is done with the > key.

On UK and US qwerty keyboards alignment the movement a tab backward and forward is done with holding shift and pressing < onwards holding both keys simultaneously and analogously with pressing shift + >
 

Best software available today for Linux video Desktop capturing on Debian

Tuesday, April 19th, 2011

I’ve been experimenting since some time in order to understand better what is the current situation with Video Desktop Capturing Software available today for Linux and FreeBSD.

My previous investigations has led me to write an article about xvidcap called How to make Video from your Linux Desktop with xvidcap

Though xvidcap works pretty well, it is currently uncapable of capturing the audio stream of a Linux Desktop env and hence part of the interactivity of the videos is missing when used.

A bit of further investigation on the topic has pointed me to 3 free software programs which are capable to record Desktop environment on Linux with sound embedded

The interesting screen video capturing Desktop tools I’ve found are:

1. recordMyDesktop
2. Istanbul
and
3. vnc2swf

Installing them on a Debian based distribution is pleasable, as there are installable debian packages of each one which I installed easily with apt:

debian:~# apt-get install istanbul recordmydesktop gtk-recordmydesktop vnc2swf

RecordMyDesktop‘s package contains a command line little tool which when started directly starts capturing video and audio of the Linux Desktop. After a Ctrl+C is pressed the program quits, saves and encodes the video in ogg-encapsulated theora-vorbis file format.

Here is the output I got in saving a sample file by launching recordmydesktop without any arguments:

hipo@debian:~/Desktop$ recordmydesktop
Initial recording window is set to:
X:0 Y:0 Width:1024 Height:768
Adjusted recording window is set to:
X:0 Y:0 Width:1024 Height:768
Your window manager appears to be Metacity

Initializing…
Buffer size adjusted to 4096 from 4096 frames.
Opened PCM device hw:0,0
Recording on device hw:0,0 is set to:
2 channels at 22050Hz
Capturing!
Broken pipe: Overrun occurred.
Broken pipe: Overrun occurred.
Broken pipe: Overrun occurred.
^C
*********************************************

Cached 5 MB, from 207 MB that were received.
Average cache compression ratio: 97.3 %

*********************************************
Saved 69 frames in a total of 69 requests
Shutting down..Broken pipe: Overrun occurred.

STATE:ENCODING
Encoding started!
This may take several minutes.
Pressing Ctrl-C will cancel the procedure (resuming will not be possible, but
any portion of the video, which is already encoded won’t be deleted).
Please wait…
Output file: out.ogv
[100%]
Encoding finished!
Wait a moment please…

Done.
Written 692529 bytes
(635547 of which were video data and 56982 audio data)

Cleanning up cache…
Done!!!
Goodbye!

The captured file as I you see in the above output is saved in file out.ogv

RecordMyDesktop has also a GUI interface (written in Python) called gtk-recordmydesktop

Below you see a screenshot of the GUI gtk-recordmydesktop:

RecordMyDesktop GTK interface entry screen

gtk-recordmydesktop is a super-easy to use as you already see in the picture, you can either configure it with Advanced button or use Save As button to select where you want the Desktop captured video and audio to be stored.

In Debian Squeeze 6.0, the Advanced GUI button interface button is not working but that’s not such an issue, as the rest of the buttons works fine.
After the recordmydesktop‘s Record button is pressed it will start capturing from your Desktop and the window seen in the above screenshot will disappear/hide in the system tray:

recordmydesktop recording minimized in system tray
When you press over the white little square in the system tray the screen capturing will be interrupted and a window will pop-up informing you that the captured video and audio is being encoded, here is another screenshot of recordmydesktop encoding a saved Desktop video stream:

recordmydesktop saving captured desktop video

After the final .ogv file is encoded and saved to further transfer it into (.flv) I used ffmpeg;

debian:~# ffmpeg -i test.ogv test.flv
...

Now let’s evaluate a bit on the the final results, the produced test.ogv‘s synchronization between sound and video was not good as the sound was starting earlier than the video and therefore even though recordmydesktop used to be highly praised on the net, the proggie developers still needs to do some bug fixing
Further on, I continued and (gave the other Desktop screen capturer) Istanbul a try hoping that at least with it the video and audio of my Linux desktop will be properly captured. But guess what, the results with Istanbul was even more unsatisfactory as the produced videos and sounds, were slow and a lot of frames from the screens were missing completely.
Moreover the sound which was supposed to accompany the video was completely 🙁

Thus I will skip on talking about Istanbul as in my view, this piece of software is far away from being production ready.

I also tested vnc2swf , launched it by: pressing alt+f2 and typing in vnc2swf in GNOME’s run application prompt, just to be surprised by an error …:

vnc2swf error no 111 Connection refused

The reason for this error is caused by the xserver (Xorg) port 5900 is being closed by default on Debian

However this error is easily solvable, by making the Xserver to listen to a the port 5900, to make the Xorg server on Debian to listen on this port you need to edit the file:

/etc/X11/xinit/xserverrc

and change inside it:

exec /usr/bin/X -nolisten tcp "$@"

with:

exec /usr/bin/X "$@"

and either reboot your Linux or restart only the Xorg server by pressing Ctrl+Alt+BackSpace

Now let me conclude, the results from my desktop video screen capturing experiments prooved that vnc2swf is superior (as it is capable of properly saving a movie with sound and video from a Linux Desktop). It appears this soft is actually the best one you can use to make a video of your Linux desktop.

Sadly my testing has proven that Linux is still lacking behind Windows and Mac in even doing the most simple tasks …
Let’s hope that situation will get better soon and Gnome or KDE developers will soon provide us with better software capable to save properly a video and audio captured from the Linux Desktop.