My iPOD, all ready to record.
When I first got my iPOD, it occurred to me that a large portable hard drive device like that should really be able to record at high quality, as well as play back. There I go again, I thought, wanting more than the designers intended.
It's not such an unreasonable demand to make, though, in my view. We have Mini-Disc recorders of a similar size, but these limit us to 80 mins of stereo, and always seem to feature an unacceptable level of unwanted motor noise when recording using those cute little plug-in mics. (as seen above) There has to be a better way, and not many of us can afford a portable DAT recorder.
So, imagine my joy when I head about the Griffin iTrip. Here was a plug-in unit which enabled recording from a built-in mic, but also enabled use of an external mic, plugged in the top. More than that, line level recording was also possible using the same mini-jack input. I was delighted, that for not much money a simple and elegant solution was on offer.
Of course, I am leading up to the let down - and here it is. The recordings are only at 8Khz, 16bit quality. Even more puzzling are that they are WAV files. Apparently this is dictated by the iPOD software designed by Apple. They didn't want to make the device into a “boot-legging” machine. I find this attitude rather parental and, of course, unwelcome.
At this point in the story, all-set as I was with my external microphones, I felt pretty fed up. Then the phone rang - it was Jason. I felt embarrassed, I really should know the difference between Jason and the phone by now. Anyhow, Jason had news. He had found an article showing how it is possible to record up to 96Khz using the iTalk and an external microphone or line input. I was, of course, instantly intrigued.
The solution is thanks, as so often, to Linux people, who are cleverer than us normal folks. Maybe a fraction nerdy, but with an almost God-like ability to suss out the most complex computer problems. I've seen them write an operating system for a satellite receiver and create countless internet server solutions - now they top it off by creating a full operating system for a closed development platform like the iPOD.
Not just like the iPOD - the iPOD itself. Awesome. Here you see the tiny kernel booting on my trusty 3rd Generation iPOD. The installer for OSX is simple and not techy at all. I love Linux booting screens - so many lines of text that means all but nothing to me. I reckon they leave the screen output on to impress us all. It works, guys.
In case you're wondering, the operating system works alongside the Apple one. You can choose which one is the default, and then access the other one whenever you fancy. If you use the Apple version more, just reboot the iPOD (MENU and PLAY together) and hold down the rewind key till PODZilla loads.
Once loaded, PODZilla looks much like the standard iPOD screen, but the font is different, as are the menu options and, of course, the games. I am using version 0.3 - which is, of course, an early beta, so there are lots of bugs. Worst bug: Well... it doesn't actually play back MP3s in anything like an acceptable way. Kinda crucial, I suppose, for an object which exists to play tunes. On this, I have faith that progress will be made. I can foresee a time when PODZilla is the OS of choice for a sector of the market.
The real joy of PODZilla for me, is that the recording at higher bit-rates really does work, and works well. Setting the bit-rate to 44.1Khz is more than sufficient for my needs. Recording through external mics is clear and clean, with no breakthrough from the mechanics of the device. There are two options for source selection: Mic and Line. I have only tested MIc, and this records a mono uncompressed WAV file. Selecting the Line option, records a file of twice the size - so I presume this would be stereo if I attached a line-in input.
The file sizes, are therefore normal for uncompressed sound files. 5Mb per minute for mono, 10Mb per minute for stereo. If you have have 20Mb left on your iPOD, that gives you around 66 hours of mono recording. Should be enough to gather a good-sized sample library, record a week of lectures or interview a whole heck of a lot of people.
I have prepared some demo files to help you judge the sound quality for yourselves:
MP3 conversion masks the true quality, but if you have just a modem connection, this is better than nothing.
FULL Test in MP3 format (708Kb)
FULL Test in AIFF format (3.8Mb)
The BUMP in AIFF format (106Kb)
96Khz Actual file in AIFF format (1.1Mb) - You will need a system capable of playing back at 96Khz for this.
I have one complaint of the recordings, and I have edited it away on all of them apart from the one that ONLY features it. This is, of course, the BUMP that is bestowed on each recording, right at the beginning. It's a shame, and I wish it was not necessary. The bump is so much louder than the actual recording, it can be quite a shock through headphones. One bug of the current build of PODZilla is that files cannot be replayed greater than 8Khz using PODZIlla itself. To hear what you have recorded, you'll need to reboot into the standard iPOD software. I'm not even sure if you can play it that way until you have docked and sync'ed.
If you open up your iPOD, once docked, all the recordings are in a folder called “Recordings” in the root directory of your iPOD. Very easy to get to and work on.
Sure, there are limitations to using the iPOD in this way, but it requires only a little patience to release your iPOD's potential as a portable hard disc recording machine. We can dream for the future that there will be lovely LED-style level displays, direct to MP3 recording and, of course, playback. I guess it will all happen in time if there is the demand and encouragement for these things.
I wish all on the project well, and I hope that this piece will play a tiny part in keeping Linux on the iPOD alive. Keep up the good work, guys. You really are clever, it's official.
Thanks for the great article (and kind words!). I'm confused that the playback in podzilla only lets you use 8KHz - that may be a problem with the release you are using because you should be able to playback anything you record.
Also regarding the "bump" at the start of the recording. That sounds like a bit of a bug. If you could drop by IRC sometime and discuss the problem with one of the developers I'm sure we could sort it out.
Posted by: Bernard | March 13, 2005 at 10:03 AM