Strange Mono ALAC Discrepancy

[MusicTrax]

I've noticed an oddity with Apple Lossless file sizes when dealing with mono audio files.

For example, I have a stereo WAV file of a mono song, which is 15.6MB. If I convert it to a mono WAV file, it shrinks down to what you'd expect: 7.8MB, exactly half as much.

Using dBPowerAmp, if I convert the stereo WAV file to a stereo FLAC file, it's 8.1MB. If I convert it to a mono FLAC file, it's 5.4MB.

However, if I convert it to a Apple Lossless file with dBPowerAmp, the file size is 8.1MB (8.2MB with iTunes). There appears to be no provision for converting to a mono ALAC file within iTunes. However, when I tried to use the "Channel Count" feature within dBPowerAmp to force the conversion to 1 channel, I get intermittent glitches in the file (which is smaller than 8.1MB).

My suspicion is that Apple did not build in any provision for mono-only files within their Lossless spec. Anybody know anything about this, or can point to specifications on the web that would go into this in detail?

[Spoon]

Re: Strange Mono ALAC Discrepancy

No I don't think there is, internally there could be some kind of fake stereo creation before encoding (in the ALAC encoder).

[MusicTrax]

Re: Strange Mono ALAC Discrepancy

No I don't think there is, internally there could be some kind of fake stereo creation before encoding (in the ALAC encoder).

Nope, it's a straight mono file. My concern is the problem with trying to create a 1-channel mono file with the "Channel" plug-in. I suspect this is an M/S (mid-side) processing artifact, and somehow the stereo difference signal goes nuts with the way dBPowerAmp is making the Apple Lossless file.

Again, mono or stereo is not a choice for Lossless available within iTunes.