There was a lot of discussion 6 months ago about the possibility of the ipod having a line-in. This discussion seems to have dried up a little, and i though i'd try and see if there has been any more advances in this field as everyone was convinced that there would be an add-on with a line-in on the market soon (anyone listening - Apple?)

It was sparked off when someone at ipodding (http://www.ipodding.com) discovered that there was an option in diagnostic mode which allowed a 6 second test of audio recording:

http://www.ipodding.com/modules.php?op=modload&name=News&file=article&sid=1135

This option in the dagnostic mode has been dissabled since firmware version 2.1.

After a bit of investigation, and pulling together of information from a few resorses, the audio chipset inside the new generations of ipod seems to consist of the PortalPlayer PP5002 digital audio processor:

http://www.portalplayer.com/products/documents/5002_brief_0108_Public.pdf

and the Wolfson WM8731L audio codec chip:

http://www.wolfsonmicro.com/products/digital_audio/codecs/WM8731/

The main points to note about the specs for these chips are:

For the PP5002:

Real-time encoding of MP3 and ACELP.NET
Real-time decoding of MP3, WMA (yes WMA!), AAC, and ACELP.NET
SPDIF interface?

For the WM8731L

ADC and DAC sampling freq: 8kHz - 96kHz (note: this does not necesseraly mean encoding at 96kHz - the PP5002 datasheet does not specify)
Stereo Line level input
Mono Mic input

So it seems that it is possible to do many things, including having a decent quality line level recorder to MP3. (I'm not that bothered if they don't include WMA support - in fact i'd rather thy didn't support it!)

There is alredy several microphone recorders (which I believe use the ACELP.NET encoder - because thats better for encoding pure voice - but I don't know too much about that format, so excuse me if i'm talking out of my arse!) which proves that apple have had the forethought to wire it up correctly! And rumours have it that the line-in signal is connected in the dock connector somewhere (all those pins have got to do something!)

I think it would be good to specify here that i'm not 'expecting' anything from Apple... as they have never advertised the fact that the iPod has any recording capabilities... it would just be another bonus, like the advent of the voice recorders.

Right, I think that enough speculation for now. I'll get back if i find anything more concrete!

Lee

PS: Please! Please! don't post any crap in this topic about the microphone voice recorders... that has nothing to do with the line-in!

PPS: If anyone has got an errm... 'unofficial' copy of the pin out for the dock connector i'd be more than a little interested...