Geek Thy Neighbor|
[ No. 6 - Apr 1997 ]
Things That Are New
Progressive Networks (the RealAudio people) have released a
RealVideo product, which adds video streaming to their existing
audio technology. We hold the usefulness of incorporating some
video content alongside your audio stuff to be self-evident.
We will begin to hint at the melding of these media in upcoming
columns. Prices start from
$295.00 without tech support. You have to pay extra for that.
Let's face it: R&D and production is expensive, we understand,
but tech support should be included in the purchase price - not
added on as an option. The above comment reflects the views of
the FezGuys, not the magazine wherein this column is printed.
LiquidAudio demo player is now available for the Mac. For
those still waiting with baited breath on word from us
regarding the Liquid Audio Beta Liquifier, we offer this
comment: "it looks great!" More later. Honestly. :}
Hello to all in print and web space, from our home in FezBurg.
This month's column finds us throwing a great handful of separate items
from the audio codecs larder at the wall of our digital dining room.
Some of these items may be news to you and some may be termed "common
knowledge." Please read on and take notes. There will be a test.
Let's posit that you have placed a file on the web. Let's assume that
it works. You know this because you received email from an ex who
successfully downloaded (or streamed) your song and, after listening to
the lyrics, felt compelled to round on you (in ascii) for divulging
secret pillow idiocyncracies. May we suggest that you expand your web
participation with a couple of new techniques and some useful
Hyperbolic jargon becomes useful information when translated into
understandable language. Uncle Al the Fez asked Reverend Jon the Fez
to give him a layman's explanation of the varying bandwidth options
available as of this writing. Is it worth getting an ISDN line in your
home? Maybe. Should you buy that dirt cheap 14.4 modem from your
Bandwidth affects the speed at which your computer interacts with the
web. Modems rated at specific levels rarely, if ever, perform that
function at their advertised speeds. You are familiar with the use of
headroom in amplification. Even though you would almost never crank up
an amplifier to its full wattage rating, having that extra space (or
headroom) contributes to the amplifier's efficiency, audio quality and
overall performance. Modems can be thought of in the same way. Just
because you have a 28.8kbps connection to your ISP, doesn't mean you
get 3.6K/sec downloads from all sites on the Internet. There are a
number of reasons for this, beginning with bandwidth and including (but
not limited to):
- The far-end computer is connected at 28.8kbps and 100 people (your
competion) are trying to download files. No doubt, we all have
experienced what happens when six lanes of freeway merge in one-- a
similar type of congestion (read: it gets slow!) happens here.
- The ISP that the far-end computer is on has a T1 into the Internet
but has 3,000 users who are also your competition.
- There is a general "network overhead" involved with the way that
data is sent over the Internet (the ubiquitous and mystic charm of
"packet switching") so that you never quite reliably get full use of
that 28.8kbps. This is the headroom analogy.
- Even though you have a 28.8kbps modem, it's a different
manufacturer than your ISP's and perhaps uses a different language
which means they only talk to each other at a lower speed like
22.0kbps. This is the Tower Of Babel analogy. Everything is shrieking
at the top of its lungs in a lexicon that requires at least one, and
usually several, interpreters.
- Your telephone line is being eaten by rats and BOY IS IT NOISY, and
therefore a lot of re-transmission brings your overall datarate from
28.8kbps to 8kbps. This is where the digital Dutchmen, with their coded
fingers in the leaking hardwire dike, are holding back the flood of
data lost during phone line transfer by casting the most holy and high
"error correction" spells.
Because of this, a RealAudio 28.8kbps stream is actually encoded at
approximately 16kbps. ShockWave audio provides for 16kbps and 24kbps
encoding rates (at the low-end). 24kbps often has dropouts on a
28.8kbps modem, so 16kbps is more commonly used.
Things That Are Useful
Do you have a dialup connection with an ISP or online service
that doesn't have a RealAudio server for realtime streaming? We
suggest that you familiarize yourself with RealAudio's HTTP
streaming solution, which allows you to stream your files
without needing the proprietary server. You should already be
familiar with the .ram metafile (FezGuys #4) which contains a
line that looks like:
To enable streaming via HTTP (the protocol your web server
runs), change it to look like:
You'll be set to go. It does require the 3.0 player at the
other end, so anyone who has been living in a cave for the last
few months will need to upgrade. Protocols and the apps that
must provide the interface between them and us humans change
like the weather. If you like change, read on. If you don't
want any more change in your life drop this magazine now!
Anyway, there is at least one disadvantage to using this format
for your stream (as opposed to purchasing a RealAudio server or
renting space on a server that someone else has purchased and
installed). The player cannot seek to random positions
throughout the file. There are other little things as well.
After all, if you are going to pay $300.00 and up for
something, you want to get features that you can't otherwise
get for free, right? As we said: R&D is expensive.
Fair enough. Using the yardstick of one minute of audio at three
levels of compression Reverend Jon the Fez was able to make Uncle Al
the Fez understand, in estimated, real world terms, what different
rates of information exchange through phone lines actually translates
into in terms of heating soup while waiting for a file to download.
If we start with a file containing...
- A: 1 minute of CD quality (44.1kHz, 16bit, stereo)
- B: 1 minute of MPEG 192kbps audio (44.1kHz, 16bit, stereo)
- C: 1 minute of 16kbps compressed audio (RealAudio 28.8, Shockwave
Audio, Xing, etc.) (5-8kHz, 8bit, mono)
...it will will take, at the following rates, this long to download said file:
14.4k (for use over standard phone lines) - The FezGuys strongly
recommend that you upgrade to at least a 28.8k modem. All ISPs should
support 28.8k by now.
- A ~ 11 hours
- B ~ 13 minutes
- C ~ 1 minute 10 seconds
28.8k (for use over standard phone lines) - This is the average home
user speed now for people browsing the Web, sending email, etc. If
you're starting to do *real work*, you might feel that this is causing
you to drink too much coffee while you wait for downloads and uploads.
- A ~ 5 hours
- B ~ 6 minutes
- C ~ 40 seconds
56k (for use over standard phone lines) - The new modem standard is in
the process of coming out of the baudy closet. ISPs will begin
supporting this as it becomes more common.
- A ~ 2.5 hours
- B ~ 3 minutes
- C ~ 20 seconds
ISDN (requires special phone line and hardware) - This can be 1 or 2
channels. 64kbps is typical, depending upon the type of telephone
service in your area.
- single channel 64kbps
- A ~ 2 hours
- B ~ 3 minutes
- C ~ 15 seconds
- dual channel 128kbps
- A ~ 1 hours
- B ~ 90 seconds
- C ~ 8 seconds
T1 - 1.54Mb (requires special phone line and hardware) Standard for
- A ~ 38 minutes
- B ~ 1 minute 15 seconds
- C ~ 2 seconds
T3 - 54Mb (requires special phone line and hardware) When you want it now.
- A ~ really fast
- B ~ the blink of an eye
- C ~ you do the math
Some useful information relevant to this table:
Nk (also Nkbps) = N kilobits per second transferred. A kilobit (kb) is
1,000 bits. A megabit (Mb) is 1,000,000 bits. A byte is 8 bits. So
28.8kbps = 28,800 bits/per/second which is 3,600 bytes per second, is
what translates to the 3.6K/sec in your Netscape download window.
The FezGuys remind you that, to play around creating audio content for
the Web as we have been discussing, the following hardware requirements
should be met: On any platform, 32MB of RAM is recommended, especially
since RAM is so cheap these days! 1GB of disk space is also
recommended (also cheap right now).
If you are PC based: a Pentium class CPU, operating at or higher than
133Mhz and a Soundcard of some sort.
If you are Mac based: the 8500 series (operating at or higher than
120MHz) are great. The 7600 series are nice, too. The 7500 series or
below cannot do live RealAudio encoding, but are fine for encoding from
pre-recorded clips. As is standard with the Macintosh machines of
these classes, the recommendations above come with built-in audio
If you are UNIX Based: there's some decent audio software for the SGI
Indy. Xing has a long history with SGI support for their software.
RealAudio supports Sun, Linux, NetBSD and SGI. In general, UNIX
systems aren't recommended unless you already have a basic
understanding of their arcane nature. The FezGuys recommend that you
stick to Mac or Windows for easy GUI (Graphical User Interface)
solutions. Point. Click. Point. Click. PANIC. System Crash.
Point. Click. (Repeat).
Coming up over the next couple of months: different software, recording
gear and technology comparisons relevant to our work.
Our first correction: thanks to several who emailed us about the
Macintosh AIF-to-MPEG audio file converstion program shareware URL. An
errant "www" slipped into the address. It should read:
May the Fez be with you!
Dear Jon and Allen, Howcum I have RA 3.0 yet it [our secret word, see
FezGuys #2] came out as a 14.4 stream when I have 28.8. Hey whatever
it works right? - David Kaufman
Indeed-- "whatever works" is often our motto :} The
FezGuy behind the curtain whispered into our ear while creating that
clip that we should make it as small as possible, thus enabling even
those struggling 14.4k modem dialup users to listen to it in real-time.
Since we did our *encoding* at 14.4k, no matter how fast your
connection is (28.8k, ISDN, or T1), you will still only receive our
14.4k sound file. Think of it this way: you still have enough bandwidth
available to download those "Kill Barney" graphics while listening to
us ramble on about secret passcodes (which has been changed, by the way).
All the best - The FezGuys
May the Fez be with you!
Please check out the FezGuys website:
We welcome your comments.