Clint Savage set out to inexpensively record audio from Linux user group
(LUG) meetings that could be easily shared. Soon after he started making
podcasts available, though, he started getting requests for video. That led
investigate cheap video hardware as well as free software solutions for
video. At the Utah Open Source Conference (UTOSC), Savage described his
journey and the solutions he has found.
Near the beginning of his talk, Savage stressed that he is not an
audio/video engineer, just an interested hobbyist, and that he was
presenting tools and equipment that worked for him—not necessarily
the "best" way to handle audio and video on Linux. He started out very
simply, using a $7 microphone from Radio Shack to record LUG meetings. He
used Audacity to add in some
introductory audio and then made the audio available as podcasts.
Once he had that working, he investigated live streaming with a
Shoutcast-compatible server. He tried Icecast, but it "took a long time to
set up". In the meantime, his listeners wanted video, and he wanted
to stay with free and open solutions while not breaking the bank, so he
started looking into cheap
For cameras, he settled on a Canon ZR80 MiniDV digital camcorder, but said
you can also use almost any webcam, including those built-in to laptops. He
wanted to be able to do screen capture for presentation slides and
screencasts, which led him to the vga2usb device from Epiphan. While
that works well, it costs around $300, so he found a much cheaper solution
using a scan converter and EZCap, which does a reasonable job for around
$60. Lowering the cost allowed him to outfit each of the half-dozen UTOSC
presentation rooms with systems capable of recording audio synced with each
For video capture software he looked, briefly, at the proprietary
offerings for Windows and Mac OS X, but was quickly put off by the price.
Not only is there the "Apple tax" on hardware, which makes it
more expensive than the equivalent Windows or Linux box, but then you need
to spend something like $3000 for video software. Windows has similar
offerings, but it is just as expensive.
For Linux, there are multiple choices for video editing (Kdenlive, Kino,
PiTiVi) and for screen capture (Istanbul, gtk-recordMyDesktop), but none of
those directly provide streaming solutions. Flumotion is a free streaming server,
but he spent three days and "never got it working". Most of
those tools use GStreamer under the
hood, though, so he started looking into that.
GStreamer is a library and set of command-line tools for handling
multimedia content. Savage showed several examples of using GStreamer from
the command line, starting with a very simple:
$ gst-launch videotestsrc ! ximagesink
and moving up into much more complex examples, including one that combined
audio and video. GStreamer is based around the idea of sources
(i.e. inputs) and sinks (i.e. outputs), along with capabilities
(i.e. filters), that can all be combined with a pipe-like syntax using '!'
rather than the shell's '|'. One can examine the available
$ gst-inspect | more
But the command line doesn't allow programmatic changes, nor changes "on
For doing more interesting things with GStreamer, Savage pointed to gst-python,
which are Python bindings for the GStreamer library. Using gst-python
allows adding and removing filters or adjusting audio/video inputs and
outputs in real-time under the control of a program. It has been used to
build various applications including audio players like Rhythmbox and Amarok.
Savage is quite excited about another, fairly new tool that uses
gst-python. Freeseer is an "open
source video studio in a backpack", according to its web page, that is
built on GStreamer, Python, and KDE. It originally used the FFmpeg command
line, but switched over to gst-python after a fairly short time. It is
designed for recording conferences, but is more versatile than that.
Freeseer has a simple interface and, as Savage demonstrated, just hitting
the "record" button starts recording the screen. It can record from
various sources, including audio sources, and is set up to tag the
multimedia files with things like which room is being recorded,
title and presenter from an RSS feed, and so on. There are some features
that Freeseer is missing—streaming, multiple video sources for
picture-in-picture, and automatic upload for example—but development
is moving quickly so those things, and undoubtedly others, will be
Savage was the executive director for this year's UTOSC, so he set up
systems using Freeseer to do the audio and slide recording for each
presentation room. He borrowed refurbished, low-end systems from the Electroregeneration society,
and added in around $100 worth of equipment (screen grabber and microphone)
for each room. He recommended a $50 Radio Shack wireless lapel microphone
as the best he had found for presentations, and recording systems only
require a Pentium 4 or better. So, for "a few hundred
dollars", anyone can put together a system to record presentations,
and it wouldn't take that much more to add in live video.
That was clearly a major part of Savage's intent with his presentation: to
conferences, LUGs, and user groups of all kinds to do more recording of the
presentations that they have. From a financial standpoint, it is well
within the budget of almost any group, and the free tools are available and
getting better. The financial barriers to entry for any
group—technical or not—are
pretty low, which is quite a change from where things stood five or even
three years ago.
Comments (4 posted)
When you build software in Java and the JVM, you are being locked
into only running it on a platform controlled by a single company -
Oracle. Oracle is working to maintain this platform control, by
refusing to remove the field of use clauses in the TCK, effectively
preventing Apache Harmony from ever being able to ship a real
release. The lawsuit against Google also confirms Oracle belief
about using their control of the platform aggressively.
As Roozbeh noted
, Unicode 6.0 came out yesterday. Somewhat fittingly (given it having been National Coming Out Day), it adds
U+1F46C 👬 TWO MEN HOLDING HANDS and
U+1F46D 👭 TWO WOMEN HOLDING HANDS
Unfortunately most people will probably be looking at small boxes with numbers in there for a while yet, which is probably a wonderful metaphor but I'm not quite sure for what.
-- Matthew Garrett
Please pull the changes below, I've forgotten about them for too
long now. They've been in my tree long enough to develop a full
colour, an exquisite bouquet and a nutty, slightly cheddary
flavour. It's just too good, I can't hold that back from
anyone. Best enjoyed with crack(ers), because clearly anyone who
tackles grab code needs that anyway.
-- Peter Hutterer
Comments (1 posted)
The first public release of EAP (Evolutionary Algorithms in Python) is out;
EAP is a package intended to make the implementation of evolutionary
algorithms easy. "This public release (version 0.6) is more complete and simpler than
ever. It includes Genetic Algorithms using any imaginable
representation, Genetic Programming with strongly and loosely typed
trees in addition to automatically defined functions, Evolution
Strategies (including Covariance Matrix Adaptation), multiobjective
optimization techniques (NSGA-II and SPEA2), easy parallelization of
algorithms and much more like milestones, genealogy, etc.
Full Story (comments: none)
For those of you looking to run Firefox on mobile devices: the
first Firefox 4 beta for mobile
is available. "Firefox 4 Beta
includes Firefox Sync to create a seamless Web browsing experience between
desktop and mobile. With Firefox Sync, you can take your browsing history,
bookmarks, tabs, passwords and form-fill data with you anywhere so you
never have to retype passwords or long URLs again.
Comments (12 posted)
The GNOME Foundation is requesting bids from developers who would like to
work toward the integration of GTK+ with the MeeGo handset platform.
"The tasks to be achieved are:
Ensure that GTK+ applications display as expected on the MeeGo Handset
platform, including checking that fixes to the compositor are made if
Full Story (comments: none)
The Linspotting project provides
a video editing workflow
that is now ready for production use. "The solution includes most features expected in professional video editing packages, such as: multi-track editing, support for a wide range of formats and codecs (mp3, mpeg2, mpeg4, DnxHD, Theora and others) and platforms (eg, Vimeo, Youtube), an important set of effects and transitions, support for screen captures, custom rendering profiles and subtitle support.
Comments (4 posted)
Pogo is a new audio player; the first release (0.1) is now available.
"Pogo plays your music. Nothing else. It tries to be fast and
easy-to-use. Pogo's elementary-inspired design uses the screen-space
very efficiently. It is especially well-suited for people who organize
their music by albums on the harddrive.
Full Story (comments: 2)
Newsletters and articles
Comments (none posted)
On his blog, KDE hacker Aaron Seigo looks
at the differences between "activities" in GNOME 3 and KDE 4. Both desktop environments use the term, but they each have their own interpretation. "They [GNOME] call this "activities" in an attempt to make the abstract and geekish "virtual desktops" more approachable to people. It is not, however, what most humans would call an activity in every day conversation. It's just a more recognizable name for an old concept that they gave some polish.
In KDE software, an "activity" is actually much closer to what we'd call an activity in the real world: it's a collection of tools with a task based theme. What the theme is remains up to the person using the computer; Plasma just provides an interface with which to create an activity and start defining what belongs to it.
Comments (16 posted)
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