Public MP3 Listening Test @ 128 kbps - CLOSED Options

[Sebastian Mares]

Greetings!

After months of endless discussion and preparation, the MP3 listening test is finally open.

The featured encoders, as most of you know already, are:

LAME 3.97
LAME 3.98.2
iTunes 8.0.1.11
Fraunhofer IIS mp3surround CL encoder v1.5
Helix v5.1 2005.08.09

The anchor used in this test is:

l3enc 0.99a as low anchor

If you want to read more before starting, the address of the test is http://www.listening-tests.info/mp3-128-1/. If you want to start right away, have a look at the readme. Please note that you do NOT have to test all samples - it is a great help even if you test one or two!

Info: The people who did not start testing already but who would like to participate, it would be very nice if you could focus especially on samples: 5, 6, 8, 9, 10, 11, 13, 14. Sample 1 already has 25 valid results, so please do not test it (of course, if you already did, you can submit your results for it, but if you just started, maybe invest time and effort in testing the aforementioned samples first).

Update: The test is scheduled to end on November 22nd, 2008.

Warning: There seem to be problems with ABC/HR when JRE 1.6 is installed. If you are affected by hangs, crashes or any other difficulties, please download and install JRE 1.5 Update 15 from http://java.sun.com/products/archive/j2se/5.0_15/index.html. You do NOT have to uninstall your existing copy of JRE 1.6 since both versions can be installed at the same time. However, if you have JRE 1.5 and JRE 1.6 installed, please make sure you start ABC/HR with JRE 1.5 manually. Since the working directory has to be the location where abchr.jar is stored, the best thing you can do is to open a command prompt window, navigate to the location where you stored abchr.jar and the rest of the files and then call "C:\Program Files\Java\jre1.5.0_15\bin\java.exe -jar abchr.jar". Of course, this is only an example which you have to adapt according to where java.exe is stored on your PC.

Note: As Hydrogenaudio Forums members and I found out, there is a bug in the iTunes MP3 encoder that is present in all iTunes versions since 5.0.1.4 (including the tested version 8.0.1.11). The problem manifests itself only on multi-core CPUs (both PCs and Macs) and leads to a significantly lower bitrate of the encoded samples. Apple engineers confirmed our findings and assured me that the next iTunes release will contain a fix for this problem. Please notice that the only functioning work-around is to disable all but one core in your computer's BIOS or to start Windows with the /numproc=1 parameter. Setting the iTunes process affinity to one core does NOT help.

Happy testing!

This post has been edited by Sebastian Mares: Nov 19 2008, 14:19