48 kbps listening test, pretest discussion thread, Pretest thread / Encoder settings Options

[Shade[ST]]

Hello!

After assisting like many of you on the controversy of guruboolez' tests concerning the Nero AAC encoders and having seen many suggestions towards preparing a listening test around 48kbps - in particular with the different HE encoders, I decided to take matters into my own hands.
I currently have 8 samples testing for tonality, transients and stereo separation. These are generally classical music, but also include electronic music, 80s pop, and I might add a jazz recording for ambience reproduction.
As for encoders, I'm stumped.

Should I also include an old version of nero (old being relative) as to see the progress in a general evaluation ? At this bitrate, many encoders is not really a problem, is it? For now, I was thinking :

-Nero AAC Tape / PNS Enabled / HE / High (Should I enable hint track?)
-Ogg Vorbis, latest AoTuV, q -2 to -4 (whatever's approximately the same bitrates ~42-53)
-Lame ABR 48 (any tunings suggested?)
-mp3pro, probably, at any close bitrate I can achieve (adobe audition's encoder)
-Itunes AAC (HE if available)
-CT encoder (winamp 5.12) 48kbps, HE.

If I should use an older nero as well, where can I find it?

Also, could anyone help me prepare the ABC/HR logs? (eg, Sebastian Mares)
Thanks in advance,
Tristan.

[Ivan Dimkovic]

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 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.

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

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

[IgorC]

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

[Halcyon]

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.