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LAME 3.98.2 VBR bitrate test, all -V settings in 0.5 step increments
Alex B
post Nov 24 2008, 18:31
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Over three years ago I tested the LAME 3.97b1 VBR bitrates (link). For that test I gathered a set of 25 various "reference" tracks. The tracks were specifically selected so that they could more or less represent an average large media library of pop/rock/jazz etc genres. Since then the same set has served well in many occasions. During the preparations of the new public 128 kbps VBR MP3 listening test I gathered another set of classical tracks.

Now I have tested all LAME 3.98.2 VBR settings (in 0.5 step increments) using these two reference sets. For this test I encoded 1050 MP3 files (21x50). I analyzed the files with EncSpot Pro v.2.1 and prosessed the exported data with Excel.

Here are the results:

Some general details: (the frequency values are kHz)


Bitrates "Various":


Bitrates "Classical":


Average Bitrates:




The test tracks:


EDIT:
The classical track #4 has a slightly incorrect name in the table. It should be "Berlin Radio Symphony Orchestra - Mahler, Symphony No 8, 2. Ewiger Wonnebrand".


The source data is available here: http://www.hydrogenaudio.org/forums/index....st&p=601002 (Excel sheet)

This post has been edited by Alex B: Dec 3 2008, 11:03


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Alex B
post Nov 25 2008, 12:59
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Thanks tosse. I did some tests and I think you are right. I should have thought about that.

When EncSpot calculates the track specific average bitrates it naturally takes the amount of each differently sized frame into account. Logically and practically it is correct to do the same when the average bitrate of a bunch of files is calculated.

If there is a 30 s 80 kbps file and a 2 min 320 kbps file EncSpot correctly reports that the average bitrate is 272 kbps instead of 200 kbps.

I'll add the EncSpot calculated average bitrates to my test results.

EDIT

On a second thought, for the purpose of this test, I am not interested about the mathematically correct disk space usage / audio duration ratio of my complete test file sets.

I am trying find out how the encoder behaves with various kinds of source material. In that sense each source track should probably be weighted equally. For instance, I may have a difficult to encode shorter track that represents a certain type of source material and an easy to encode longer track that represents another type of source material.

In any case this is not going to be an exact science.

This post has been edited by Alex B: Nov 25 2008, 14:01


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Posts in this topic
- Alex B   LAME 3.98.2 VBR bitrate test   Nov 24 2008, 18:31
- - guruboolez   Excellent and useful work. This table should appea...   Nov 24 2008, 19:06
|- - Alex B   QUOTE (guruboolez @ Nov 24 2008, 20:06) O...   Nov 24 2008, 20:17
|- - tosse   QUOTE (Alex B @ Nov 24 2008, 21:17) I not...   Nov 25 2008, 08:45
- - Alexxander   Thanks for sharing your helpfull information. The ...   Nov 24 2008, 19:15
- - DigitalDictator   I wonder what the plot (or chart) would look like ...   Nov 24 2008, 19:42
|- - Alex B   QUOTE (DigitalDictator @ Nov 24 2008, 20...   Nov 24 2008, 20:51
|- - /mnt   QUOTE (Alex B @ Nov 24 2008, 20:51) QUOTE...   Nov 24 2008, 22:14
- - melomaniac   Thank you for this interesting bitrate table. Very...   Nov 24 2008, 19:49
- - senab   QUOTE (Alex B @ Nov 24 2008, 20:17) I not...   Nov 24 2008, 22:21
- - kornchild2002   I saw that the Evanescence track suffered from the...   Nov 24 2008, 23:25
- - /mnt   And for some reason Powerslave by Iron Maiden real...   Nov 24 2008, 23:37
- - Alex B   Actually I really would not like to start testing ...   Nov 25 2008, 00:12
- - CiTay   I updated the bitrate estimates on the LAME page a...   Nov 25 2008, 00:20
- - /mnt   I have made a table of 29 sfb21 bloated tracks at ...   Nov 25 2008, 01:27
- - skelly831   Great info guys! the ~60kbps savings with -Y a...   Nov 25 2008, 07:01
- - Alex B   Thanks tosse. I did some tests and I think you are...   Nov 25 2008, 12:59
- - Pio2001   Hello, A bit surprised by the low target bitrate o...   May 31 2009, 19:31
- - MClemo   On my collection of 12579 files I got an average b...   Jun 1 2009, 10:42


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