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. (duh!) 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 information.

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 neighbor? No!

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):

1. 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.

2. 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.

3. 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.

4. 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.

5. 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: pnm://realaudio.server.com/path/to/yourfilename.ra To enable streaming via HTTP (the protocol your web server runs), change it to look like: http://web.server.com/path/to/yourfilename.ra 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 most ISPs.

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 input/output jacks.

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: <http://home.ptd.net/~warnergt/>

May the Fez be with you!

Letters To The FezGuys

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

---

Dear David:

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: <http://www.fezguys.com/>

We welcome your comments.