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Nero 48 kbit/s HE-AAC (+v2) Test - STARTED!
Ivan Dimkovic
post Jan 24 2006, 12:13
Post #1


Nero MPEG4 developer


Group: Developer
Posts: 1466
Joined: 22-September 01
Member No.: 8



Dear All,

I would like to announce that the 48 kbps test of upcoming Nero AAC encoder has just started. The purpose of this test is to determine which bit allocation mode gives highest quality, and how big the quality difference is between ABR, CBR and VBR.

With this test, I wish to include true audiophile and scientific community into making the HE-AAC /v2 solutions even better in the future. Many thanks in advance for your help!

Test runs for 10 days, Until february 3rd 2006. It should be much easier and more interesting to the wide audience than the last 128 kbps test, since I hope many more people would be able to actually judge the quality smile.gif

So, What's in?

There are two tests actually - Test 1 and Test 2.

- Test 1 contains HE-AAC v1 tracks (AAC+SBR)
- Test 2 contains HE-AAC v2 tracks (AAC+SBR+Parametric Stereo)

The reason why they are split is that rating HE-AAC vs HE-AAC v2 is not the point of this test (it is the point of the next public 48 kbps multivendor AAC test coming in February)

Which codecs are tested?

For both tests, following codecs are being tested:

- HE-AAC (or v2) CBR - Constant Bit Rate, optimized for online streaming
- HE-AAC (or v2) ABR - Average Bit Rate, little bit more pre-buffer delay, more room for "hard to encode" frames
- HE-AAC (or v2) VBR v1 - Quality iterated VBR 1
- HE-AAC (or v2) VBR v2 - Quality iterated VBR 2
- MP3 at 128 kbps (LAME -b128) *** High Anchor ***
- MP3 at 48 kbps (LAME -b48) *** Low Anchor ***

Difference between quality iterated VBR modes is in the bit allocation strategy. All encoding modes (except high anchor) should produce clips of average bit rate close to the 48 kbps.

How To Test

1. Download test1.rar and test2.rar (links in the next message)

2. Extract these two RAR files in separate directories (for example, C:\TEST1 and C:\TEST2)

3. Download samples for the test, and extract them in the directory of the test (so, test1_atrain.rar should go to C:\TEST1 and test2_atrain.rar should go to C:\TEST2)

4. When you download all the samples, in each test directory (C:\TEST1 or C:\TEST2 in example) execute the decode_all.bat files. This will decode all the files and prepare the test. Note that you have to do it for both tests separately.

5. Alternatively, you can download and decode each sample, and execute individual bat files to decode just that sample (e.g. for test1_atrain.rar, unpacked in C:\TEST1, you have to execute C:\TEST1\atrain.bat)

6. Now everything is ready for the test, and the file structure should look like:

CODE
C:\TEST1\
C:\TEST1\ATRAIN\
                           atrain.wav
                           atrain_codeca.wav
                           atrain_codecb.wav
                           atrain_codecc.wav
                           atrain_codecd.wav
                           atrain_codece.wav
                           atrain_codecf.wav



7. Open ABC/HR by executing abchr.jar - and, to test each sample, open up the individual .ecf files. Each test set (test1 or test2) has an .ecf file for each sample.

8. From now on, typical ABC/HR methodology applies, you need to judge the quality of individual files - save the results after you're done, and send the files to me, either by PP or directly to: idimkovic (at) nero.com (replace at with @ to get an e-mail address)

Samples coming in the next post...

Happy Testing smile.gif

This post has been edited by Ivan Dimkovic: Jan 24 2006, 12:47
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Posts in this topic
- Ivan Dimkovic   Nero 48 kbit/s HE-AAC (+v2) Test - STARTED!   Jan 24 2006, 12:13
- - Ivan Dimkovic   Sample selection Total 14 samples are tested, exp...   Jan 24 2006, 12:20
|- - Shade[ST]   Finally it started! I'm going to take part...   Jan 24 2006, 14:24
|- - IgorC   ftp://ftp.morbo.org/pub/Nero_48_Test/test2_atrain....   Jan 24 2006, 15:18
- - Ivan Dimkovic   Thanks IgorC for noticing it - It is corrected now...   Jan 24 2006, 15:21
- - sehested   QUOTE (Ivan Dimkovic @ Jan 24 2006, 03:13 AM)...   Jan 24 2006, 15:39
- - Ivan Dimkovic   QUOTE - Will ranking any reference make the result...   Jan 24 2006, 16:04
- - Firon   Do we have to perform all the tests for the result...   Jan 26 2006, 00:12
- - Ivan Dimkovic   You can do both the tests, or a single test, or on...   Jan 26 2006, 09:26
- - vinouz   suggestion : a little shell script instead of the...   Jan 26 2006, 19:24
|- - IgorC   Maybe it is my ignorance but it seems to me there ...   Jan 29 2006, 03:42
- - Ivan Dimkovic   QUOTE suggestion : a little shell script instead o...   Jan 30 2006, 20:20
- - archish   which which version of nero encoder is HE-AAC v2 s...   Jan 31 2006, 12:58
- - Ivan Dimkovic   Basically all recent Nero7 AAC encoders have HE-AA...   Jan 31 2006, 13:17
- - Ivan Dimkovic   2 more days left for the test. Due to lack of res...   Feb 1 2006, 12:56
- - Alex B   I am not promising anything, but I could give it a...   Feb 1 2006, 13:42
- - Gabriel   QUOTE Due to lack of results (3 for test 1, 1 for ...   Feb 1 2006, 14:14
- - Ivan Dimkovic   Actually the results I mentioned are excludig @ner...   Feb 1 2006, 14:32
- - Firon   I'm still working on it, I've been busy un...   Feb 2 2006, 01:51
- - Ivan Dimkovic   Just a quick note - test is definitely extended un...   Feb 3 2006, 10:38


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