IPB

Welcome Guest ( Log In | Register )

Possible Poor Performance Of Alt-presets, found a problem sample?
KikeG
post Sep 23 2002, 23:58
Post #1


WinABX developer


Group: Developer
Posts: 1578
Joined: 1-October 01
Member No.: 137



I've just doing some ABX tests with the sample trumpets1.wav, which you can find at http://www.pcabx.com/product/reference/trumpets1.wav

It's a trumpet sound, with no pre-echo issues, just added harshness on some alt-presets.

My results:

--alt-preset standard: 6/6 p= 1.6%, quite easy
--alt-preset standard -Z : 7/7 p= 0.8%, quite easy
--alt-preset extreme : 7/7 p= 0.8%, quite easy
--alt-preset extreme -Z : 12/14 p= 0.6%, seems more difficult, or I'm more tired
--alt-preset insane: 3 trials, total 20/32 p=14%, quite difficult, I think I can ABX it on optimum conditions, but I can't prove it right now rolleyes.gif . Edit: not so sure I can ABX it...





So, seems that the VBR alt-presets have more room for tuning?
Go to the top of the page
+Quote Post
 
Start new topic
Replies
wkw
post Sep 24 2002, 17:36
Post #2





Group: Members
Posts: 85
Joined: 7-June 02
Member No.: 2241



I did some studies on the awe32.wav clip with AAC encoder. It has the same problem as with fatboy.wav. The attacks are too closely spaced and somehow, temporal processing is not sufficient to compensate for pre-echo.. As a result it is necessary to switch to short-block completely just as Ivan has pointed out for fatboy.wav (search for AAC forum about QTime MPEG4 encoder)..



wkw
Go to the top of the page
+Quote Post

Posts in this topic


Reply to this topicStart new topic
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:

 



RSS Lo-Fi Version Time is now: 16th April 2014 - 16:05