IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
Lame 3.99.3x, A functional extension
halb27
post Dec 8 2011, 15:59
Post #1





Group: Members
Posts: 2414
Joined: 9-October 05
From: Dormagen, Germany
Member No.: 25015



I finished work on 3.99.3x. It can be downloaded from here.
The functional extension is invoked by using -Vx+ instead of -Vx.

The functional extension - technically speaking
a) inaccurately encoded frames are avoided
Compared to 3.98.4, Lame 3.99.3 does a good job at avoiding inaccurate frames. It uses a frame packaging strategy which covers the issue while being efficient in not introducing unused data in the output file. Lame 3.99.3 doesn’t use specific restrictions any more for 320 kbps frames. Moreover the way the sfb21 extremely high frequency range is treated helps on the problem.
3.99.3x goes a bit beyond. -V0+ avoids usually 50 to 75 per cent of the out of data space situations left over from -V0. For more details read the doc file provided by the download link.
b) keeping a minimum audio data bitrate
Lame 3.99.3x controls the audio data bitrate and keeps it above a certain value depending on -V level. The control is more stringent compared to my previous 3.98.4x version. (This is also the case for the data space control for avoiding inaccurate frames.)

The functional extension - properties of -the various -Vx+ levels
The functional extension is working from -V7.5+ to -V0+.
For level -V7.5+ to -V2+ it is assumed that users care much about quality and efficiency. That's why bitrate increase from -Vx to -Vx+ is very moderate in this quality level range. Nearly nothing is done for avoiding inaccurate frames - it's not necessary here. Minimum audio data bitrate requirements are not very demanding.
For the levels above -V2+ up to -V0+ it is assumed that users care very much about quality, but not about efficiency. That's why this quality level range covers the average bitrate range from 200 up to nearly 320 kbps. -V1.5+ makes internal use of -V1, -V1+ uses -V0 internally. Minimum audio data requirements howver are still quite moderate up to -V1+. Above -V1+ up to -V0+ -V0 is used internally, and minimum bitrate requirements are becoming more and more severe.

The functional extension - a listening test
a) -V5+ against -V4.75 (135 kbps both on average for my standard test set of various pop music)
-V4.75 is the better choice. For details see the doc file.
b) -V2+ against -V1.55 (200 kbps both on average)
-V2+ is the better choice. For details see the doc file.
c) -V0+ against -V0 (maximum settings both in their environment, unequal contenders of course)
-V0+ is the better choice. For details see the doc file.
d) Comparing with 3.98.4x
For a comparison I ported the 3.99x mechanism back to 3.98. I also transfered some 3.99 goodies (frame packaging strategy for levels up to -V2, sfb21 behavior).
I did all the tests I did for 3.99.3x for this new 3.98.4x. The results were similar, with the exception that 3.98.4x -V5+ makes sense in the 3.98.4 world.
I compared the 3.98.4x results with the 3.99.3x results, and they were in favor of 3.99: As well as for -V5+ as for -V2+ 3.99.3 is to be preferred. For -V0+ none of the versions is better than the other. For details see the doc file here.
The difference is due to the improvements of 3.99 over 3.98 and has nothing to do with the functional extension deschribed here.

This post has been edited by halb27: Dec 8 2011, 16:09


--------------------
lame3100m --bCVBR 300
Go to the top of the page
+Quote Post
IgorC
post Dec 8 2011, 20:34
Post #2





Group: Members
Posts: 1506
Joined: 3-January 05
From: Argentina, Bs As
Member No.: 18803



Interesting.

I have tried V0+ for one album. It gives very high bitrate > average 319 kbps . I suppose this is the way it works.
~17.5 kHz lowpass is incredibly adequate and the encoder sounds amazingly clean and still detailed. I like it. Will give a detailed try to it. smile.gif
Go to the top of the page
+Quote Post
Hanseat
post Dec 8 2011, 22:23
Post #3





Group: Members
Posts: 9
Joined: 22-July 11
Member No.: 92467



Thanks for 3.99.3x. Im going to start testing tomorrow.
Go to the top of the page
+Quote Post
halb27
post Dec 9 2011, 00:28
Post #4





Group: Members
Posts: 2414
Joined: 9-October 05
From: Dormagen, Germany
Member No.: 25015



@IgorC and Hanseat: Your tests are very welcome.
@the moderator who corrected the topic: thank you very much.


--------------------
lame3100m --bCVBR 300
Go to the top of the page
+Quote Post
Thorolf
post Dec 9 2011, 08:04
Post #5





Group: Members
Posts: 5
Joined: 6-November 11
Member No.: 94992



Fantastic, halb27!

Thanks a lot for your efforts! Now, if I could only convince the XLD team to allow standard LAME binaries, so I could swap myself... ;-)
Go to the top of the page
+Quote Post
ShotCaller
post Feb 13 2012, 05:30
Post #6





Group: Members
Posts: 34
Joined: 8-August 11
Member No.: 92854



Hey halb27, would you mind making and uploading 3.99.5 with your extension? I guess not until it is finalized and released (soon I think). Thanks, and thanks for making my MP3 encoder of choice.
Go to the top of the page
+Quote Post
halb27
post Feb 13 2012, 09:56
Post #7





Group: Members
Posts: 2414
Joined: 9-October 05
From: Dormagen, Germany
Member No.: 25015



Yes, there will be a 3.99.5x, but as you said, not before the official 3.99.5 will be released.

Moreover, I am thinking about some additions, and 3.99.5x could be an occasion to put them in. In case I will it will probably take a bit longer especially as I am busy with other things at the moment.


--------------------
lame3100m --bCVBR 300
Go to the top of the page
+Quote Post
ShotCaller
post Feb 29 2012, 23:30
Post #8





Group: Members
Posts: 34
Joined: 8-August 11
Member No.: 92854



hey halb27, just wondering what the status of 3.99.5x is now that 3.99.5 has been officially released. Please excuse my anxiousness. Thanks!
Go to the top of the page
+Quote Post
halb27
post Mar 1 2012, 00:22
Post #9





Group: Members
Posts: 2414
Joined: 9-October 05
From: Dormagen, Germany
Member No.: 25015



Now that 3.99.5 is out I'm going to work with 3.99.5x within the next days.
First I'll find out whether or not it makes sense to take care of some additions. So please be a bit patient at the moment. As long as you don't have the very special problems 3.99.4 and 3.99.5 solved you can use 3.99.3x. That's exactly what motivates me to investigate additional functionality: without it you won't get any advantage of 3.99.5x over 3.99.3x. The bitrate bloat issue for quiet passages doesn't apply to 3.99x, and the other issues fixed with 3.99.4 and 3.99.5 are not relevant to 'normal' usage of Lame.


--------------------
lame3100m --bCVBR 300
Go to the top of the page
+Quote Post

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: 25th April 2014 - 03:01