Stream Recording from the Internet

Audio stream recording from the Internet...

This is the first attempt I've made to document my approaches to capturing audio streams.

Capturing the stream versus Recording the Audio

Internet audio is subjected to what is called "lossy compression." The various formats - mp3, Windows Media, Real, etc. - are ways of reducing the huge amount of data required for full-fidelity sound while still sounding halfway decent. Each has its advantages, disadvantages, and adherents, and there are all kinds of comparative tests on which sounds best at different bitrates, etc.

At first, I just used an audio recording program to record the audio directly from the player program onto the hard disk. If you recorded it to a CD-quality uncompressed file - usually 16-bit WAV files at a 44.1 kHz sample rate (lossless format, no "lossy compression" involved - you would have no loss of quality from the original, but you've increased the file size tremendously. Now, if you were to recompress the files to, say, a typical 128 kbps mp3 file, you will have gained some hard disk space, but added ANOTHER step of "lossy" compression. So even if you were listening to 128 kbps mp3 off the Internet, saving it as an uncompressed WAV file, and re-compressing it to 128 kbps mp3... you have just submitted the audio to TWO steps of lossy compression, which is less than desirable. If the original source were of lower quality, say a 48 kbps Windows Media stream, you would probably be even worse off if you re-compressed it into another "lossy" format. Various added audio distortions and artifacts can result depending on how closely you listen.

Thus began my quest to capture the streams directly, at their original quality.

The tools are out there. This site, all-streaming-media, was my starting point. You want to make it easy? Just go there and buy their recommended commercial products!

But no, not me! The open-source software movement has provided free community-supported tools to do this, if you want to get your hands dirty with scripting, using command-line interfaces, and so on. That's the approach I've dealt with here.

A lot of this is closely associated with Linux. I use Windows for most day-to-day work, but with many forays into Ubuntu Linux on the desktop as well. Since the kids usually want to do their thing on most of the good computers, constantly logging in and out, I wanted to have one or two machines dedicated to server and multimedia recording functions 24/7. And with some older slower machines lying around, why pay for more copies of Windows XP or <gasp!> Vista for these older machines? A server with Ubuntu Server (no fancy grapical interface) is an old Celeron 500 MHz machine with only 256 MB RAM, and keeps up pretty well for light-duty file and web serving. And my "old faithful" first PC, a 600 MHz Pentium 3 with 256 MB RAM, runs Ubuntu in full graphical mode, and is accessed remotely via VNC from any computer in the house, and sometimes the world too! My personal e-mail is also on this machine.

The combination of the multimedia programs VLC Media Player and mPlayer with the powerful scripting and scheduled task capabilities of Linux takes care of capturing Internet radio automatically at various scheduled times. These programs are available for Windows as well, and much of this can be done with the Windows "scheduled task" function and "batch files" capability. But a dedicated machine for recording would be most desirable, otherwise all the background tasks popping up while you or the family are doing something else might be a problem, and the constant logon-logoff of users would also cause problems.

VLC is a veritable "Swiss Army Knife" of media playback, saving, streaming, and transcoding capabilities. It is also more complicated to use, with a mind-boggling array of interfaces and capabilities and a labyrinth of command-line structures that can just fry your brain. mPlayer is a bit simpler, and with some help from cron (Linux task scheduler) or "Scheduled Tasks" (in Windows) you can do most of what you need with it. But VLC is worth learning, too, as I found some Internet radio sources which for mysterious reasons mPlayer could not handle that VLC could. Helps to have those alternate tools on hand...