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Alternative Multiformat Listening Test @ 128 kbps, at SoundExpert with the same contenders
Serge Smirnoff
post Jan 13 2006, 17:46
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As Sebastian Mares have practically finished accepting test results from participants I would like to offer for all who care to take part in alternative listening test with the same codec contenders but different sound samples. Testing methodology is also a bit different and makes testing much easier because sound artifacts are clearly audible in most cases. The main task of a listener is to grade annoyance of those artifacts.

Test files could be downloaded from here – ftp://www.soundexpert.info
Each time you click the link you’ll get random test file for one of these codecs:
• Nero AAC 3.1.0.2
• iTunes AAC 6.0.1.3
• LAME 3.97 Beta 2
• Ogg Vorbis AoTuV 4.51 Beta
• WMA Professional 9.1
• Shine 0.1.4 (Low Anchor)
Inside zip file you’ll find brief instruction and form for submitting results. The whole testing procedure is not hard and takes approx. 2-3 min., so you could easily test 5-10 files in one session. Each test file is 2-3 Mb.

Results of this test will appear on this page the same time with Sebastian Mares ones. After that they could be monitored in real time as new participants will add their grades.

Testing methodology used is described here - http://www.soundexpert.info/prozone.htm

Hope, comparison of both tests results will be interesting. If someone has any questions I am glad to answer.


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keeping audio clear together - soundexpert.org
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Ivan Dimkovic
post Jan 16 2006, 23:43
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QUOTE
So, using layers at higher than sweet spot bitrates is inefficient and could be reasonable for compatibility only.


I don't think that is really completely true - "Layers" were introduced basically because of pure performance reasons - to provide "scaling" in quality vs. CPU performance (there was probably also another reason, but it is out of scope of this forum wink.gif

Since MPEG-1 codecs were standardized in 1989/1990, therefore it was very important also to maintain low performance requirement for at least some coding modes because during that time DSPs being able to run audio coding were very expensive, and MPEG probably needed to keep everybody happy - therefore 3 layers were defined.

Layer III flaws, that prevent it to always outperform others were introduced by design requirement to be somehow "backwards compatible" with Layers I and II (which it is of course not) - without these limitations, MP3 would be very similar in its nature to LC-AAC excluding TNS and window shape switching, and with slightly inferior huffman coding smile.gif

QUOTE
(AAC is going to be an exclusion from this rule – time and tests will show)


It has been already shown, some 9 years ago - AAC @320 kbps was better than MP2 @640 kbps for 5.1 channel material smile.gif

This post has been edited by Ivan Dimkovic: Jan 16 2006, 23:46
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Posts in this topic
- Serge Smirnoff   Alternative Multiformat Listening Test @ 128 kbps   Jan 13 2006, 17:46
- - jido   QUOTE (Serge Smirnoff @ Jan 13 2006, 08:46 AM...   Jan 14 2006, 11:26
|- - Serge Smirnoff   QUOTE (jido @ Jan 14 2006, 01:26 PM)So the te...   Jan 14 2006, 12:19
- - loophole   Artificial stimuli? As opposed to music? Isn't...   Jan 14 2006, 12:32
|- - Serge Smirnoff   QUOTE (loophole @ Jan 14 2006, 02:32 PM)Artif...   Jan 14 2006, 12:46
- - DigitalDictator   Interesting to check out the comparisons at other ...   Jan 14 2006, 12:58
|- - Serge Smirnoff   QUOTE (DigitalDictator @ Jan 14 2006, 02:58 P...   Jan 14 2006, 13:46
- - DigitalDictator   QUOTE BTW, are you sure that mp2 has to be worse t...   Jan 14 2006, 14:00
|- - Serge Smirnoff   QUOTE (DigitalDictator @ Jan 14 2006, 04:00 P...   Jan 14 2006, 14:34
|- - Garf   QUOTE (Serge Smirnoff @ Jan 14 2006, 03:34 PM...   Jan 14 2006, 14:52
|- - guruboolez   QUOTE (Garf @ Jan 14 2006, 02:52 PM)QUOTE (Se...   Jan 14 2006, 15:27
|- - Serge Smirnoff   QUOTE (Garf @ Jan 14 2006, 04:52 PM)QUOTE (Se...   Jan 16 2006, 23:29
|- - halb27   QUOTE (Serge Smirnoff @ Jan 17 2006, 12:29 AM...   Jan 16 2006, 23:52
|- - Serge Smirnoff   QUOTE (halb27 @ Jan 17 2006, 01:52 AM)[What a...   Jan 17 2006, 00:03
- - Garf   Note the parts "256kbps", "Often...   Jan 14 2006, 15:36
|- - guruboolez   QUOTE (Garf @ Jan 14 2006, 03:36 PM)Note the ...   Jan 14 2006, 15:46
- - Jan S.   As far as I recall Klemm actually considered to mo...   Jan 14 2006, 15:56
- - Garf   If you spend more bits on the right coefficients, ...   Jan 14 2006, 16:15
|- - guruboolez   QUOTE (Garf @ Jan 14 2006, 04:15 PM)That...   Jan 14 2006, 16:56
|- - halb27   QUOTE (guruboolez @ Jan 14 2006, 05:56 PM)......   Jan 16 2006, 21:52
- - Garf   The problem of PS and SBR is that they are paramet...   Jan 14 2006, 18:13
- - guruboolez   The testing procedure of this second listening tes...   Jan 15 2006, 04:28
|- - Serge Smirnoff   QUOTE (guruboolez @ Jan 15 2006, 06:28 AM)Wha...   Jan 15 2006, 11:37
- - guruboolez   I understand. The procedure is indeed very easy to...   Jan 15 2006, 12:07
|- - Serge Smirnoff   QUOTE (guruboolez @ Jan 15 2006, 02:07 PM)The...   Jan 15 2006, 12:49
- - Sebastian Mares   Just noticed something on the page... QUOTE aac A...   Jan 15 2006, 13:15
|- - Serge Smirnoff   QUOTE (Sebastian Mares @ Jan 15 2006, 03:15 P...   Jan 15 2006, 18:25
- - Ivan Dimkovic   QUOTE So, using layers at higher than sweet spot b...   Jan 16 2006, 23:43
- - Ivan Dimkovic   "Sweet spot" comes from the relatively s...   Jan 17 2006, 00:11
- - Sagittaire   Just my 2 cents ... ;-) 1) Well ... not really 12...   Jan 18 2006, 13:26
- - Gabriel   QUOTE 1) Well ... not really 128 Kbps test but 140...   Jan 18 2006, 13:39
|- - Sagittaire   QUOTE The resulting overall on overall music is ab...   Jan 18 2006, 14:15
- - Alex B   The bitrates were measured with a big amount of co...   Jan 18 2006, 13:45
- - Alex B   BTW, this thread is about the alternative Sound Ex...   Jan 18 2006, 13:58
- - Garf   The ability of a codec to distribute more bits to ...   Jan 18 2006, 14:28
- - pepoluan   Just noticed that on SoundExpert site, the lower b...   Jan 19 2006, 18:01
- - Serge Smirnoff   QUOTE (pepoluan @ Jan 19 2006, 08:01 PM)Consi...   Jan 20 2006, 00:00


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