Category: Tech

[Long post warning: Read if you want to record internet audio streams on the Macintosh]

I’m a big fan of the CBC Radio1 show Ideas. Over the years, I have found that it provides some of the most consistently thought-provoking content available on radio. My only problem is that the broadcast time for Ideas is weekdays from 21h05 until 22h00, a period when I am almost always busy. To circumvent this, I need a way to time-shift the program so that I can listen to it later (typically, either when I go to bed or on the way into work the next morning).

As most of you know, I am a Mac-weenie. This website lives on my G5 server/DAW, as does my iTunes library. I sync my iPod to that library, so the easiest way to access the Ideas content is using the iPod. Given this, the problem statement becomes: How do I record CBC Radio1 (weekdays from 21h05 to 22h00) and convert the result into something I can listen to on my iPod?

The Content

Like all forward-thinking broadcasters (:-P), CBC Radio is available on the web, which means that I ought to be able to record it, without needing to physically hook up an FM tuner. Unfortunately, they have standardized on Windows Media Player, which they tell me is the “most commonly used” format. They would, of course, have been better off standardizing on the most compatible format, rather than the most popular one, but at least they make the content available.

The CBC online listening page explains that Mac users should use the Flip4Mac Windows Media plugin to play WMA content. I have this plug-in, but for me at least, if I follow the Ottawa Radio1 link, I get dubious results. There is something wrong with one or more of…

• the CBC stream,
• the Flip4Mac plug-in, or
• Safari’s caching strategy

… that causes the resulting embedded Quicktime player to play the same 10 minute clip whenever I go there. That is, it will only play 10 minutes of audio before the “thumb” on the player reaches the end of the scrollbar, and returning to the same page at a later time will cause it to play the same 10 minutes of audio as last time — not very useful.

I imagine others have had problems using the WMA streams as well, since despite the claim that they were going to standardize on one format, it turns out that you can also listen to an Ogg Vorbis stream of (at least) Toronto’s Radio1 feed. I would have prefered getting the stream from Ottawa, but given that Ideas is available on both, I am set.

Or am I?

Setting Up the Recording

It turns out that iTunes is not able to play the “.m3u” wrapped Ogg Vorbis stream, but it at least recognizes that it is continuous (i.e. not just 10 minutes long). As usual, when faced with an audio or video file that I cannot play with the standard tools, I then pull out VLC, which is a very nice freeware audio/video player available for all major operating systems. I can’t say enough good things about VLC; if it wasn’t for some un-Mac’ish GUI choices, it would always be my first choice.

VLC happily connects and starts playing the OV stream, but wouldn’t you know it, it too stops after 10 minutes. Very odd. It has worked fine for other streaming content I have tried, which seemingly adds credence to the theory that there is something wrong with the way the feeds are being created, but who knows?

After trolling around on the web for a while, I discover that some problematic audio will play correctly from the command line VLC player, even though it will not play in the GUI application. Sure enough,…

/Applications/VLC.app/Contents/MacOS/VLC \
    http://www.cbc.ca/livemedia/cbcr1-toronto.m3u

… works perfectly, so I finally have something that I can use to listen to CBC. Whew!

The next step is actually recording it.

I believe the best application for recording the audio output of arbitrary programs on the Mac is Audio Hijack Pro. I purchased the Pro version because it has some nice features that I use more for digital audio work. There is also a non-Pro version, which seems like it would be perfectly fine if all you want to do is record something at a scheduled time. As of the time of this posting, it costs 16 $US (it’s a whopping $32 for the Pro version).

You can configure Audio Hijack to:

1. Start any program you want on a flexible, repeating schedule.
2. Record the audio output of that program (and not any other sounds your Mac is making) to a file of your choosing, optionally appending a timestamp to allow multiple recordings to be kept.
3. Mute the output of the program, so that you don’t hear it, even though it is being recorded.
4. Automatically exit the program after the recording is complete
5. Import the resulting file into iTunes

As you can see, this is perfect for the task at hand. There is a wide range of format options for the recordings, including both MP3 and AAC at many bitrates. I use 48kbps AAC to record Ideas, which produces a listenable recording in an approximately 20Meg file (for 55 minutes).

The program I run is just a shell script that has the above command line in it, and that’s all there is to it.

A Final Note

It would not surprise me at all to find out that there are simpler ways to get this process going. What I ended up with is largely a result of trial-and-error. It works, but it’s not pretty. If you have found a better answer, feel free to leave a comment.