After having a few busy weeks, I find a day available to finally do this. Define in my own time, and with my own ears an audio codec test.
I was particularly taken by the promises from iTunes and Dubbers enthusiasm for converting his digital music collection from mp3 to the new AAC/mp4 technology, and since I'd also heard a bit about the open source OGG, I decided I needed to do this.
For testing I played the media through windows media player 9, winamp and foobar (for AAC/MP4) to get player perspectives. I have also written this so my Mum can understand what the hell it's all about.
Each test has a place winner, from first to fifth.
The first test I did was for - 128kbps, 44.1 stereo (CBR)
#1 The best sounding was MP3 although it wasn't the smallest file size.
#2 MP2 had a lot of high frequency 'bubbling' (Sounds like its underwater)
#3 OGG lost some treble.
#4 Windows Media Player was slow to play its own WMA files! Lots of lag and sounded metallic.
#5 AAC/MP4 was the worst sounding at this setting. just horrible.
The second test was 192kbps, 44.1 stereo, (CBR). Things should be really close to perfect here but,
#1 MP3 was as close to clean as could be, with a tiny bit of high frequency 'bubbling', but was hardly noticeable.
#2 AAC/MP4 certainly made up for its suckful performance at 128kbps.
#3 WMA still had a metallic sound to it, but had the smallest file size.
#4 MP2 still had some high frequency clipping, but not bad on the whole.
#5 OGG regained its top end, but still some bubbling on vocals.
Anything higher on any of these codecs should have been unnoticeable. So I went downward to streaming quality.
The final test was at 64kbps, 44.1 stereo, (CBR). I was looking for the cleanest, and most bandwidth friendly codec.
#1 OGG wins!. Double Take!! OGG is VERY clean and has a crisp top end. It also has the smallest file size, because it actually played at 57kbps. Unbelievable!
#2 WMA comes in a close second. Small chunk sizes, and you can hear the top end losing fidelity, but sounds ok on pc speakers.
#3 AAC lost a lot of top end. It sounds much better than mp3, considering they are the same file size.
#4 MP3 lands fourth, with only bass and midrange only. Pitiful output.
#5 MP2 is dead last in the streaming test. Sounds like an AM radio station. Muddy as hell.
#1 Big winner was still MP3 with general cross-compatibility, and consistent file sizes with most other competitors.
#2 Second runner up goes to OGG for its brilliant performance for streaming.
#3 Third place is MP2, for being a general all rounder considering its old age.
#4 Fourth place goes to WMA for best effort without superior result.
#5 finally, AAC lands last place - because of its general incompatibility, slow conversion times and average result.
HARD-DISK PLAYBACK = MP3 (winner)
FILE SHARING = MP3 (winner)
STREAMING = OGG (winner)
note - Real Media was not included because the codec could not be obtained, and it generally sucks anyway. Maybe Dubber should hold off?