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48 kbps listening test, pretest discussion thread, Pretest thread / Encoder settings
dimzon
post Dec 13 2005, 17:20
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QUOTE (Ivan Dimkovic @ Dec 13 2005, 01:42 PM)
QUOTE
don't forget about 3GP reference encoder:
http://forum.dbpoweramp.com/showthread.php?t=7107


There are two things to take care when using it:

- It works only with 48 kHz input
- At 48 kbps, it will produce HE-AAC v1 Streams


there are quick fix to allow 44.1 kHz input !
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Ivan Dimkovic
post Dec 13 2005, 17:34
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QUOTE
Any word of yet as to how any of these tests are going to be set up?


As for my idea of 48 kbps AAC-only pre-test, I am still waiting for the reply of the person I mentioned (sorry to keep name private, I will of course reveal it as soon as/if he accepts)

My proposal (to be discussed further) would be the following:

#1 - We will have open discussion on HA of the sample set, that should last couple of days - my current idea and proposal would be to use 10-15 samples that scored worst in previous Roberto's 64 and 128 multiformat listening tests. "Worst" means lowest average SDG for all codecs used to code that sample, excluding low-anchors

#2 - Myself and Person X wink.gif will encode files in CT's, Nero's and anchor formats, previously agreeing on the coding modes, and making public verification of the bitrates.

#3 - We will exchange the files and verify they are the same and within the bit-rate criteria

#4 - We will preapre and sign the ABC-HR test sets, upload the file and store the codec list.

This is just my rough idea about the AAC pre-test - I do have very strong belief that testing v1 and v2 HE-AAC modes @48 kbps would have a huge value before the multiformat 48 kbps test.

QUOTE
I think Gabriel has a good idea at comparing various AAC contenders before a multiformat test; Also, organizing many tests might make people feel more enthusiastic about the community, and thus conduce a retour en force of hydrogenaudio.


Agreed completely smile.gif

I also think that it would be good that HA as the whole takes more active role in this - people behind the test organization would surely get the credit, and HA could host the results as unique one-and-only listening test database.

This post has been edited by Ivan Dimkovic: Dec 13 2005, 17:37
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IgorC
post Dec 13 2005, 19:40
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It wil be good to see not only music samples but also movie tracks (for video encoding), (wo)man speech for radio. This way test will be more usefull for different aplications.

Maybe it will be also interesting to see how perform codec with and withoust PS.
48 kbit/s (VBR aprrox 51-52 kbit/s) is highest bitrate when PS is still usefull.

This post has been edited by IgorC: Dec 13 2005, 19:41
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Halcyon
post Dec 13 2005, 21:24
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Before you start any test, I suggest you take the sane advice given already in this thread.

Also, read all the previous pre-test discussion threads very carefully and ask if you don't understand something.

The first question any tester should ask is: why am I doing this test? What do I want to find out.

Define your test question first.
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user
post Dec 14 2005, 12:00
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QUOTE (Sebastian Mares @ Dec 12 2005, 05:52 PM)
  • 128 kbps extension test featuring ATRAC3, MusePack and WMA Standard (later might be problematic because of the settings)
  • Low bitrate (32/48/64 kbps) multiformat test
  • Low bitrate (32/48/64 kbps) AAC test

*


As said by Gabriel, it would make sense to make an AAC test first, maybe on personal basis, or only few interested participaters, to select best AAC.
Then a multiformat low bitrate 48k test, including lame abr48, and maybe Fraunhofer, if that is known to be best mp3@48, we will see, that is the reason for tests. Excluding mp3 from those tests is not appropriate, as it is most widespread and compatible encoder.


[*]128 kbps extension test featuring ATRAC3, MusePack and WMA Standard (later might be problematic because of the settings)

I have said already something to this,
best solution imo: set down the averaged all-music bitrate from 128k down to 9x or 10x k., so that wma suits regarding bitrate. And, as bitrate is lower than 128k, testing is little bit easier.


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Ivan Dimkovic
post Dec 14 2005, 12:43
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Gabriel and I discussed these ideas - and we will organize this 48 kbps AAC pre-test somewhere near the end of Jaunary.

I will soon post the general ideas for the test, so we could discuss them before anything is done smile.gif

Basically, the test should test current state-of-the-art AAC encoders at 48 kbps:

* HE-AAC v1: Nero Digital HE-AAC v1, Coding Techologies aacPlus, 3GPP Reference Encoder

* HE-AAC v2: Nero Digital HE-AAC v2, Coding Technologies Enhanced aacPlus

* Low-Anchor: LC-AAC at 48 kbps

* High Anchor: Maybe MP3 @128 kbps?

So the main idea of the test is not just to chose best candidates for the 48 kbps multiformat, but also to verify the usefullness of Parametric Stereo at this bet rate, as well as to check the quality of the 3GPP reference encoder.
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fpi
post Dec 14 2005, 16:45
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Before testing aoTuV beta 4.51 would be interesting compare beta 4.51 with beta 4, looking which has better quality (beta 4.51 should have better quallity with q < 3, but no one have confirmed it).
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gameplaya15143
post Jan 18 2006, 04:15
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QUOTE (fpi @ Dec 14 2005, 10:45 AM)
Before testing aoTuV beta 4.51 would be interesting compare beta 4.51 with beta 4, looking which has better quality (beta 4.51 should have better quallity with q < 3, but no one have confirmed it).
*

i cant hear any difference between them, the latest version should probably be used unless problems are found.

suggested encoding settings:
vorbis aotuv b4.51: -q -.5 --resample 37800 --advanced-encode-option lowpass_frequency=17
lame v3.93.1: -q 1 -V 9 --lowpass 9 --resample 22 --nspsytune (about 48kbps, and sounds better than lame3.97 abr 48 IMO)

what about including plusV in this test? (i know, i know, its old and dead, but it is meant to be used with low bitrates) the only improvement i have hacked into the plusV reference software is control over the plusV bands, the ability to encode down to 16khz input, and the ability to have full control over how the mp3 portion is encoded rolleyes.gif . Was plusV ever included in any listening tests? I for one am curious how people would rate it.

edit: corrected lame command line
edit2: 'better' vorbis settings

This post has been edited by gameplaya15143: Jan 21 2006, 05:40


--------------------
Vorbis-q0-lowpass99
lame3.93.1-q5-V9-k-nspsytune
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pepoluan
post Jan 19 2006, 17:51
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Ahhh... the thread has been resurrected tongue.gif

So. Is this test for real? What if we put a link on the Current Events wiki page informing about another up-coming test? Although it is currently still in pre-test discussion stage... so the link should point to this pre-test discussion instead smile.gif

If the test will go through, of course.


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I am Nobody.

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