IPB

Welcome Guest ( Log In | Register )

7 Pages V  « < 5 6 7  
Reply to this topicStart new topic
64 kbps listening test 2005, Pre-test thread
Sebastian Mares
post Jul 9 2005, 18:13
Post #151





Group: Members
Posts: 3633
Joined: 14-May 03
From: Bad Herrenalb
Member No.: 6613



I think it'd be better to conduce an 128 kbps test once LAME 3.97 and Nero AAC are out.


--------------------
http://listening-tests.hydrogenaudio.org/sebastian/
Go to the top of the page
+Quote Post
Sagittaire
post Aug 12 2005, 00:07
Post #152





Group: Members
Posts: 28
Joined: 17-April 04
Member No.: 13559



I vote for WMA9 Pro and Sdt because:
1) Not the same codec
2) wma9 pro was never tested to 64 Kbps
3) hardware compatibility is not a problem : HE-AAC or MP3Pro are not compatible with hardware
4) wma9 sdt vs wma9 pro fight is very interessing

WMA9 Standard setting
I think that for very bitrate the best setting could be that:
cscript.exe wmcmd.vbs -a_codec WMA9STD -a_mode 4 -a_setting 64_44_2 -a_peakbitrate 96000 -a_peakbuffer 5000 -input C:\Audio -output C:\Audio

-> Max bitrate is 96 Kbps : lower variability
-> Max buffer = 5 sec : lower variability
In fact with these setting wma9 is between real VBR and real CBR and IMO it's better for overall quality at very low bitrate

WMA9 Pro sample
In theory it's impossible to make WMA9Pro with exact bitrate at 64Kbps (no profil for 64 Kbps target bitrate) but if you want I can make these encoding with exactly 64 Kbps for each sample in two pass mode.
Go to the top of the page
+Quote Post
rjamorim
post Aug 12 2005, 01:16
Post #153


Rarewares admin


Group: Members
Posts: 7515
Joined: 30-September 01
From: Brazil
Member No.: 81



QUOTE (Sagittaire @ Aug 11 2005, 08:07 PM)
2) wma9 pro was never tested to 64 Kbps


It is not even meant to be used at 64kbps.

QUOTE
3) hardware compatibility is not a problem : HE-AAC or MP3Pro are not compatible with hardware


HE AAC is actually playable on some cell phones. And MP3pro is playable on several Thomson/RCA devices, among other brands.

QUOTE
4) wma9 sdt vs wma9 pro fight is very interessing


It is not a fight. Not even Microsoft is interested in that fight! For them, WMA Std is the consumer codec, meant to be used for CDDA resolution at 64kbps. WMA Pro is the professional codec meant to be used at high resolutions, multichannel streams, at bitrates higher than 128kbps.

QUOTE
WMA9 Standard setting
I think that for very bitrate the best setting could be that:
cscript.exe wmcmd.vbs -a_codec WMA9STD -a_mode 4 -a_setting 64_44_2 -a_peakbitrate 96000 -a_peakbuffer 5000 -input C:\Audio -output C:\Audio

-> Max bitrate is 96 Kbps : lower variability
-> Max buffer = 5 sec : lower variability
In fact with these setting wma9 is between real VBR and real CBR and IMO it's better for overall quality at very low bitrate


Settings tweaking IST EVUL.

QUOTE
WMA9 Pro sample
In theory it's impossible to make WMA9Pro with exact bitrate at 64Kbps (no profil for 64 Kbps target bitrate)
*


There you go. WMA Pro is not meant to be encoded at 64kbps.

This post has been edited by rjamorim: Aug 12 2005, 01:18


--------------------
Get up-to-date binaries of Lame, AAC, Vorbis and much more at RareWares:
http://www.rarewares.org
Go to the top of the page
+Quote Post
pieroxy
post Aug 12 2005, 09:03
Post #154





Group: Members
Posts: 51
Joined: 16-February 05
Member No.: 19890



QUOTE (Sebastian Mares @ Apr 1 2005, 07:19 PM)
Regarding samples, I have enough now, thank you. It's a bit hard to decide which ones to use, since almost all of them are more or less killer samples.
*


Beware of the bias of testing only killer samples. Comparing codecs on killer samples will only give you a hint on how they perform... on killer samples. Not on regular music. See here for a thread on the subject.


--------------------
http://nerds.palmdrive.net
Go to the top of the page
+Quote Post
level
post Aug 12 2005, 18:20
Post #155





Group: Members
Posts: 42
Joined: 18-May 05
Member No.: 22125



QUOTE (pieroxy @ Aug 12 2005, 02:03 AM)
Beware of the bias of testing only killer samples. Comparing codecs on killer samples will only give you a hint on how they perform... on killer samples. Not on regular music. See here for a thread on the subject.
*

Not necessarily. You remember that many killer samples (in particular here in this thread) are only regular music. In other words, are situations of the real life. Tuning any encoder with "difficult parts of music" (killer samples) in order to do it more robust is the way as HA has managed to improve the performance of the encoders.
Go to the top of the page
+Quote Post
xmixahlx
post Aug 12 2005, 19:21
Post #156





Group: Members
Posts: 1394
Joined: 20-December 01
From: seattle
Member No.: 693



QUOTE (pieroxy @ Aug 12 2005, 01:03 AM)
Beware of the bias of testing only killer samples. Comparing codecs on killer samples will only give you a hint on how they perform... on killer samples. Not on regular music. See here for a thread on the subject.
*

keep your ridiculous ideas on conducting listening tests to your own thread.


later


--------------------
RareWares/Debian :: http://www.rarewares.org/debian.html
Go to the top of the page
+Quote Post
echo
post Aug 12 2005, 20:29
Post #157





Group: Members
Posts: 165
Joined: 31-January 04
Member No.: 11670



QUOTE (pieroxy @ Aug 12 2005, 12:03 AM)
QUOTE (Sebastian Mares @ Apr 1 2005, 07:19 PM)
Regarding samples, I have enough now, thank you. It's a bit hard to decide which ones to use, since almost all of them are more or less killer samples.
*


Beware of the bias of testing only killer samples. Comparing codecs on killer samples will only give you a hint on how they perform... on killer samples. Not on regular music. See here for a thread on the subject.
*


Heh, now this has become a fact? wink.gif

QUOTE (Sebastian Mares @ Jul 9 2005, 09:13 AM)
I think it'd be better to conduce an 128 kbps test once LAME 3.97 and Nero AAC are out.

I think that would be more interesting for everyone...
Go to the top of the page
+Quote Post
Sebastian Mares
post Aug 12 2005, 20:55
Post #158





Group: Members
Posts: 3633
Joined: 14-May 03
From: Bad Herrenalb
Member No.: 6613



QUOTE (echo @ Aug 12 2005, 09:29 PM)
I think that would be more interesting for everyone...
*


I bet the two encoders will be released right after my summer vaction is over. tongue.gif Hope not.


--------------------
http://listening-tests.hydrogenaudio.org/sebastian/
Go to the top of the page
+Quote Post
rjamorim
post Aug 12 2005, 21:39
Post #159


Rarewares admin


Group: Members
Posts: 7515
Joined: 30-September 01
From: Brazil
Member No.: 81



QUOTE (Sebastian Mares @ Aug 12 2005, 04:55 PM)
I bet the two encoders will be released right after my summer vaction is over. tongue.gif Hope not.
*


You might have LAME 3.97 beta before your vacation is over, but you'll hardly have final!


--------------------
Get up-to-date binaries of Lame, AAC, Vorbis and much more at RareWares:
http://www.rarewares.org
Go to the top of the page
+Quote Post
Sebastian Mares
post Aug 12 2005, 21:51
Post #160





Group: Members
Posts: 3633
Joined: 14-May 03
From: Bad Herrenalb
Member No.: 6613



Would you test with a beta or a final?


--------------------
http://listening-tests.hydrogenaudio.org/sebastian/
Go to the top of the page
+Quote Post
rjamorim
post Aug 12 2005, 22:11
Post #161


Rarewares admin


Group: Members
Posts: 7515
Joined: 30-September 01
From: Brazil
Member No.: 81



QUOTE (Sebastian Mares @ Aug 12 2005, 05:51 PM)
Would you test with a beta or a final?
*


Wise words from Roberto:

Ask the Developers opinion. That way, you save your face and don't get cornered in case everything blows up. smile.gif


--------------------
Get up-to-date binaries of Lame, AAC, Vorbis and much more at RareWares:
http://www.rarewares.org
Go to the top of the page
+Quote Post
Sagittaire
post Aug 13 2005, 00:52
Post #162





Group: Members
Posts: 28
Joined: 17-April 04
Member No.: 13559



QUOTE (rjamorim @ Aug 12 2005, 01:11 PM)
Settings tweaking IST EVUL.


arghhhhhh .... smile.gif
then 2 pass streaming mode with default setting : it's an usual mode in WMEnc
cscript.exe wmcmd.vbs -a_codec WMA9STD -a_mode 4 -a_setting 64_44_2 -input C:\Audio -output C:\Audio

default are:
- 1.5*bitrate for maxbitrate
- 3 sec for maxbuffer

QUOTE (rjamorim @ Aug 12 2005, 01:11 PM)
There you go. WMA Pro is not meant to be encoded at 64kbps.


In fact q10 quality is perhabs this mode ... but it's just impossible for you to obtain the good target bitrate for your specific samples tests ...

This post has been edited by Sagittaire: Aug 13 2005, 00:53
Go to the top of the page
+Quote Post
guruboolez
post Aug 19 2005, 05:10
Post #163





Group: Members (Donating)
Posts: 3474
Joined: 7-November 01
From: Strasbourg (France)
Member No.: 420



QUOTE (xmixahlx @ Aug 12 2005, 07:21 PM)
QUOTE (pieroxy @ Aug 12 2005, 01:03 AM)
Beware of the bias of testing only killer samples. Comparing codecs on killer samples will only give you a hint on how they perform... on killer samples. Not on regular music. See here for a thread on the subject.
*

keep your ridiculous ideas on conducting listening tests to your own thread.
*


Pieroxy's ideas have nothing ridiculous. He was very clear: a listening test involving VBR and CBR encoders should include low-bitrate encodings, mid-bitrate encodings and high-bitrate encodings.
I'm quoting Pieroxy:
QUOTE
So in an ideal test, you would have 160kbps, 130kbps and 90kbps samples. THAT would be representative, not merely 128kbps.


Now I'm quoting someone who's not used to post "ridiculous ideas" about listening tests, ff123:
QUOTE
Ideally, you'd like the bitrate distribution to look somewhat like a bell curve with its mean at 128 kbit/s.

=> Exactly the same "ridiculous" idea about the "ideal" test.

And ff123 followed:
QUOTE
For the 48 kbit/s test, if there are VBR codecs, I think we should strive to have about an equal number of bitrates above and below the average bitrate (which should work out to be 48 kbit/s on average across the sample set).

Would you also say that ff123 has ridiculous ideas about listening test organisation? I'd really like to see that...



I posted the bitrate distribution curve of VBR encoders involved in my latest 80 kbps listening test:
http://foobar2000.net/divers/tests/2005.07...UTION_WMA80.png
http://foobar2000.net/divers/tests/2005.07...ION_aoTuV80.png

For both encoders, ~50% of the total samples were encoded with a bitrate lower to the targeted bitrate, and the ~50 remaining percent were encoded with a bitrate superior to the targeted bitrate. The distribution is close to the perfect curve for WMA and classical music (150 samples), with both mean and median at exactly 80 kbps. The curve is perfectible for aoTuV (median is 75 kbps), but distribution is also near-symetrical from both side of the median value.
It was maybe luck - I don't know - or maybe a consequence of the huge number of samples involved in my test (150+35) which maybe help to get a good distribution.

This post has been edited by guruboolez: Aug 19 2005, 05:27
Go to the top of the page
+Quote Post

7 Pages V  « < 5 6 7
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: 26th November 2014 - 21:21