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#1 | Link |
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L.A.M.E. developer
Join Date: Dec 2001
Location: Paris - France
Posts: 276
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48kbps AAC public listening test
A 48kbps AAC public listening test is coming:
http://www.mp3-tech.org/content/?48k...0public%20test |
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#3 | Link | |
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Registered User
Join Date: Feb 2006
Posts: 36
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Listened to a few samples, but honestly I think my audio-sensory organs need a tuning...
![]() Sometimes 1 or 2 were noticably worse than others, yet most of time it was hard for me to distinguish between them. As for the 48kbps itself, what is the target for the codecs? I have listened to online radio a lot, and that was on dial-up. One thing was for sure, listening to anything over 32kbps was sure to result in interrupted broadcasts. As this test is intended to see progress in AAC HEv2 compared to others wouldn't it make sense to test ER (Error Resilience) as well? The AAC paper features many techiniques to limit audio degradation during limited transfer speeds. This goes for mobile transmission as well, of course. So... if broadcast or mobile use is (also) scope of the test it might be more usefull to ask / set up an online broadcast (degredation here can be equalled to that of mobile networks) and have 1 station use the 4-5 codecs you want tested for a week. Listeners can then just casually listen and switch between station no. 1, 2, 3 etc. without having to pay full attention to comparing. After a week there'd sure be preferences over 1 station over another, you can allways simulate transmission failure during the test to test resillience of the codes. Naturally, all this is moot when you're interested in locally stored samples, but I for one don't see the use in cbr 48 for that. Also, the AAC amendment doesn't seem to focus on that and sort of states that AAC LC is intended for those purposes. hope i'm making sense here. Timetable : Quote:
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The average person thinks he isn't.
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#4 | Link |
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Registered User
Join Date: Apr 2004
Posts: 1,317
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The test was extended untill 19 of the March. There are not enough results for test. Please, participate in this test.
We all need to know wich HE-AAC is good, right? PS (HE-AAC2) is not always better (but often even noticebly worse) than simply SBR (HE-AAC1) at 48 kbits. That's another good reason to do this public test. Thank you. For each sample as minimum 15 results are needed. http://www.hydrogenaudio.org/forums/...howtopic=41598 Single result is accepted. Last edited by IgorC; 12th March 2006 at 19:11. |
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#5 | Link |
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Registered User
Join Date: Apr 2004
Posts: 1,317
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The test is finished.
http://www.hydrogenaudio.org/forums/...howtopic=42679 |
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#6 | Link |
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L.A.M.E. developer
Join Date: Dec 2001
Location: Paris - France
Posts: 276
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Test results are now available:
http://www.mp3-tech.org/tests/aac_48/results.html ![]() *Nero and CT are both quite competitive *3gpp code is quite good for a reference code *It seems that parametric stereo does not overall bring benefits at 48kbps. |
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#7 | Link |
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nobody's nobody
Join Date: Mar 2005
Location: The Sun, somewhere around
Posts: 553
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One thing which cannot be overlooked here is that the NERO encoder was using ABR(new implementation) while others were encoded with CBR.
If the segment of the ABR becomes larger, I guess it becomes closer to VBR(same overall bit rate) which is considered more than 10% more efficient than CBR. We are not sure, ATM, what kind of ABR algorithm is used in the encoder, as well as how differently it is affecting the PS encoding : note the difference 317 - 308(9 for CT CBR) < 329 - 310(19 for Nero ABR) . It can also mean the CBR is more efficient than ABR or VBR for the PS encoding. With that small sample size, I agree the results are statistically tied, with an exception of the (itune's) LC encoding. But still it can also mean the lower bit rate LC encoding is not efficient with CBR at all.
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u know everything in the end, or now if aligned... no right(x).right(y) pls. it's confusing... : phase-shift /Jun.2006 |
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#8 | Link | |
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BluRay Maniac
Join Date: Dec 2005
Posts: 2,419
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Quote:
Last edited by shon3i; 21st March 2006 at 12:39. |
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#9 | Link |
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Registered User
Join Date: Feb 2003
Posts: 67
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There was a listening test on Hydrogenaudio where various Nero encoding modes were tested:
http://www.hydrogenaudio.org/forums/...howtopic=41191 ![]() So, it could be seen that the difference between Nero ABR and Nero CBR is not that big: Nero VBR1 - 3.56 Nero ABR - 3.53 (note, this is exactly the same encoder as used in Gabriel's test) Nero CBR - 3.48 Difference Nero CBR/Nero ABR - 1.4% (absolute) And, in the current test we have: Nero ABR - 3.29 CT CBR - 3.17 Difference CT CBR/Nero ABR - 3.78% (absolute) It is very hard to compare two different tests, but since Nero codecs are the same as used in Gabriel's test I am quite convinced that Nero, if forced to pure CBR mode, would still be a bit better than CT CBR. Also, this is the same old argument we are seeing on many tests - but long time ago the decision was made to test the best what a codec could offer at a bit-rate range - if CT does not have VBR / ABR - it is not the fault of the other encoders with more advanced options. Besides, Nero ABR was well within the bit rate deviation limits on this test (in fact it was less than average bit rate of the test) - so I cannot see any reason to complain. Just my 2 eurocents
Last edited by Ivan Dimkovic; 21st March 2006 at 13:36. |
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#10 | Link | |
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nobody's nobody
Join Date: Mar 2005
Location: The Sun, somewhere around
Posts: 553
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I appreciate the hydrocents! Grains of salt.. I will drop by more often to read the news, even if I am not planning on posting on the forum yet.
Btw, a recent CT based-Winamp5.1 encoder DLL frontend CLI (enc_aacPlus.exe) now seems to support the bitrate-based(better result size estimation than quality based one) vbr(or abr) encoding. Quote:
If it is related to naac.exe's quality grades(3~10) and actually having the varying bitrate to keep the given even quality grade, I believe the algorithm would be very different than CT's one. And of course, it would be very hard to get the similar overall bit rate(yeah, it didn't mentioned the result bit rates for the vbr keys), which makes the comparison vary rough on the very bitrate-sensitive low-bitrate area. The ABR with entire segment would be similar to CT's one, if I am correct. Another thing to mention is the algorithm optimization for the target bitrate zone : I guess the AAC HE is optimized for the bit rate around 64k(ST) , overlapped then surpassed by PS(optimized @ around 32k?) below 48k. If the VBR(or ABR) does not yield the noticeably(far more than 2.2% I guess) better quality than CBR, I believe it's the algorithm optimization problem on the zone. Lastly, my common sense has been VBR > ABR > CBR theoretically and practically by some reasonable margin. I seem to need some more precise data to be understood by such as : . performing some comparison between CT CBR, VBR(or ABR I am not sure), Nero CBR, ABR and VBR. . quantitative analysis with more accurate/relevant data & strictly controlled variables. ... Thanks.
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u know everything in the end, or now if aligned... no right(x).right(y) pls. it's confusing... : phase-shift /Jun.2006 Last edited by Rockaria; 21st March 2006 at 14:49. |
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#11 | Link | ||||
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Registered User
Join Date: Feb 2003
Posts: 67
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With that in mind - I think even 2.2% quality improvement is a success ![]() But I do expect 2-pass to yield even better results, so there is definitely more space for improving. Last edited by Ivan Dimkovic; 21st March 2006 at 15:04. |
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#12 | Link | |
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Testeur de codecs
Join Date: May 2003
Location: France
Posts: 2,546
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Quote:
CT HE-AAC V1 : 46.22 Kbps Nero HE-AAC V1 : 47.94 Kbps Difference CT CBR/Nero ABR - 3.72% (absolute) always these bitrate problem ...
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Le Sagittaire ... ;-) 1- Ateme AVC or x264 2- VP7 or RV10 only for anime 3- XviD, DivX or WMV9 |
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#13 | Link |
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Registered User
Join Date: Apr 2004
Posts: 1,317
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@Sagi.
Audio bitrate issue is different from video. Yes there is different on short samples. Try to do : 1. Encode 1 CD 10-20 songs with CT CBR 48 kbps and Nero VBR v3 (48 kbprs). You will see the same size. 2. But when you will cut some part of the song and will evualuate that bitrate has very big variance. VBR buffer is repected so final size of a big files (like 10 songs of CD or soundtrack 1-2 hours) will have 48 kbit/s. You already discused it with guys from HA so do I. ![]() You know how hard for me to agree with facts sometimes but I did it ![]() If you will read some information about it you will find it's abolutly normal if bitrate is higher on short testing Last edited by IgorC; 21st March 2006 at 18:20. |
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#14 | Link | |
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BluRay Maniac
Join Date: Dec 2005
Posts: 2,419
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Quote:
But my personaly notice is that this test is unfair beacouse CBR and ABR can't compare, ABR is much better in all cases. This test is very good and i not agins't Nero but name of the test is wrong. For me the test will be right if in test be used old N7 codec. Bye |
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#15 | Link |
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Registered User
Join Date: Nov 2001
Posts: 9,770
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isnt ct's encoder available for free?
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Between the weak and the strong one it is the freedom which oppresses and the law that liberates (Jean Jacques Rousseau) I know, that I know nothing (Socrates) MPEG-4 ASP FAQ | AVC/H.264 FAQ | AAC FAQ | MP4 FAQ | MP4Menu stores DVD Menus in MP4 (guide) Ogg Theora | Ogg Vorbis use WM9 today and get Micro$oft controlling the A/V market tomorrow for free |
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#16 | Link | |
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BeHappy/MeGUI developer
Join Date: Oct 2003
Location: Moscow, Russia
Posts: 1,727
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Quote:
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BeHappy - AviSynth-based audio transcoding tool Audio encoding via AviSynth On2 VP7 is great in quality but it is unusable for long-term video backup puposes! Sincerely Yours, MCPD/MCTS |
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#17 | Link |
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Registered User
Join Date: Apr 2004
Posts: 1,317
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NO!!!!! (God gave me capslock for a little while) It's not free http://www.winamp.com/player/
To encode to AAC+ pro version $19.90 . It's some kind of demo version like Nero7 package. It's not meaning if you are free to download pro version you can use it forever for free. Another time politic games what is freeware what's shareware etc. "Use FAAC if you open source beleiver. Nero,Apple and CT are commercial products." Good point, isn't it? Open source and commercial projects are always here *together* . Without open source com. prods would not exist and vice versa without com. projects nobody will working on reference code. Last edited by IgorC; 21st March 2006 at 19:58. |
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#18 | Link | |
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BeHappy/MeGUI developer
Join Date: Oct 2003
Location: Moscow, Russia
Posts: 1,727
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Quote:
http://www.winamp.com/player/free.php
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BeHappy - AviSynth-based audio transcoding tool Audio encoding via AviSynth On2 VP7 is great in quality but it is unusable for long-term video backup puposes! Sincerely Yours, MCPD/MCTS |
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#19 | Link | |
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Registered User
Join Date: Feb 2003
Posts: 67
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#20 | Link | |
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BeHappy/MeGUI developer
Join Date: Oct 2003
Location: Moscow, Russia
Posts: 1,727
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Quote:
Nero is not free so using aacenc32.dll from Nero (without having Nero licence) is illegal
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BeHappy - AviSynth-based audio transcoding tool Audio encoding via AviSynth On2 VP7 is great in quality but it is unusable for long-term video backup puposes! Sincerely Yours, MCPD/MCTS |
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#21 | Link | |
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BluRay Maniac
Join Date: Dec 2005
Posts: 2,419
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#22 | Link | |
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Registered User
Join Date: Feb 2003
Posts: 67
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#23 | Link | |
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BeHappy/MeGUI developer
Join Date: Oct 2003
Location: Moscow, Russia
Posts: 1,727
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Quote:
__________________
BeHappy - AviSynth-based audio transcoding tool Audio encoding via AviSynth On2 VP7 is great in quality but it is unusable for long-term video backup puposes! Sincerely Yours, MCPD/MCTS |
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#25 | Link |
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Registered User
Join Date: Apr 2004
Posts: 1,317
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Dimzon
please read what it says here http://www.winamp.com/player/ : AAC+ costs 20$. If you donwloading free Winamp 5.21 and get .dll files and use it for your cli is totally illegal beacuse you did not use restriciton of speed 6.x . Your cli doesn't use any restriction. It's illegal. You also support higher than 128 kbit/s and it's available only in pro version. Nero7 is updating each month so theoricly speaking you have a 30 days trial each month for personal use. Yes. That's is. When one commercial encoder is better than open source or freeware there is nothing to say but "na na na. I like open source" Ok Nero isn't open source but it's best HE-AAC encoder. And that's I'm caring about. Quality. If it's open source or payware it's another question. Don't mix economics and politics factors. That never was usefull. Last edited by IgorC; 21st March 2006 at 21:11. |
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#26 | Link | ||
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BluRay Maniac
Join Date: Dec 2005
Posts: 2,419
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Quote:
Quote:
Last edited by shon3i; 21st March 2006 at 21:22. |
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#27 | Link |
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Registered User
Join Date: Apr 2004
Posts: 1,317
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Free version only up to 128 kbit/s http://www.winamp.com/player/free.php
Nero is the best HE-AAC Stereo encoder You can't be disagree with the results of professional public test.
Last edited by IgorC; 21st March 2006 at 21:27. |
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#28 | Link |
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Registhreaded User
Join Date: Mar 2005
Location: Serbia
Posts: 94
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I think that codecs should be judged by maximum quality they can reach with fixed filesize no matter what modes are used.
Codecs with more features should not be punished. There was similar discussion where MSU limited AVC video codecs to main profile and 1 pass in their testing and thats not good. I cant wait to test 2pass nero audio encoder. It should do wonders with movies with lots of silence compared to CBR and ABR... just my 2 pare
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#29 | Link |
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BluRay Maniac
Join Date: Dec 2005
Posts: 2,419
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@IgorC i know that diagram and whole day i debate with Ivan Dimkovic about that on some local forum. Newermind. I agree with result but this result is unfair beacouse Nero use ABR instead CBR. Someone can tell me that only 2% difference is ABR than CBR, but i think that is not true because ABR is more better. That's my notice. The right result will be if on test be used old Nero7 codec. Bye
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#32 | Link | |||
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Blah!
Join Date: Jul 2002
Location: Brazil
Posts: 337
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#33 | Link |
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Registered User
Join Date: Apr 2004
Posts: 1,317
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I know that estadisticly it's not sure to say what codec is better. They are all tied, except 3GP. I've learned probability and estadistic. Yes, it's not correct to interpret like that.
I also understand that it wasn't ideal test and maybe it wasn't correct from my part to say "professional public". But in the same time this test is enough fair (based on abxing of 18 samples by approx. 12-16 persons) . P.S. My personal respect to people from neigbour Brazil. Igor Cavalera and Lula da Silva well knowed people. Igor Cxxx is my real name. It's coincidence. Tudo bem!
Last edited by IgorC; 22nd March 2006 at 02:57. |
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#34 | Link | |
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L.A.M.E. developer
Join Date: Dec 2001
Location: Paris - France
Posts: 276
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Quote:
However, we are more than 95% sure that all contenders are lower quality than Lame -V5 (high anchor) and higher quality than iTunes (low anchor). |
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