IPB

Welcome Guest ( Log In | Register )

 
Reply to this topicStart new topic
what is mpeg2 layer 3?
rdo
post Aug 16 2005, 10:29
Post #1





Group: Members
Posts: 7
Joined: 3-August 05
Member No.: 23665



Hi everyone,

I've got some files that have mp3 extension.
My player shows that they have bitrate 80kbs and frequency 225000.
EncSpot shows me that they are of type mpeg2 layer III.

I wonder what is this mpeg2 layer III? I thought mp3 is of type mpeg1 layer III.

I find that my files are very small in size and still the quality is acceptable.
Anyone that has experience with such encoding? Does it worth to try it? How to encode and how to achieve good results?
Go to the top of the page
+Quote Post
DreamTactix291
post Aug 16 2005, 10:48
Post #2





Group: Members (Donating)
Posts: 552
Joined: 9-June 04
From: A place long since forgotten...
Member No.: 14572



Has to do with the samplerate and possible bitrates.

CODE
        Sample Rates   Bitrates
MPEG-1  32, 44.1,  48  32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320
MPEG-2  16. 22.05, 24  8,  16, 24, 32, 40, 48, 56, 64,  80,  96,  112, 128, 144, 160


This post has been edited by DreamTactix291: Aug 16 2005, 10:48


--------------------
Nero AAC 1.5.1.0: -q0.45
Go to the top of the page
+Quote Post
Sebastian Mares
post Aug 16 2005, 10:57
Post #3





Group: Members
Posts: 3629
Joined: 14-May 03
From: Bad Herrenalb
Member No.: 6613



If the sampling rate is lower than 16 KHz, the files are MPEG 2.5. smile.gif
AFAIK, MPEG 2.5 is not an official standard but was introduced to support low sampling rates.

This post has been edited by Sebastian Mares: Aug 16 2005, 10:58


--------------------
http://listening-tests.hydrogenaudio.org/sebastian/
Go to the top of the page
+Quote Post
SebastianG
post Aug 16 2005, 12:18
Post #4





Group: Developer
Posts: 1317
Joined: 20-March 04
From: Göttingen (DE)
Member No.: 12875



The mpeg2 specification not only contains a low sampling rate extension but also a multichannel extension.

Sebi
Go to the top of the page
+Quote Post
Synaptic Line No...
post Aug 16 2005, 15:41
Post #5





Group: Members
Posts: 92
Joined: 19-May 05
Member No.: 22137



I noticed that the mp3 sound files that are part of the game "Sid Meier's Alpha Centauri" are MPEG2.
Go to the top of the page
+Quote Post
DreamTactix291
post Aug 16 2005, 17:47
Post #6





Group: Members (Donating)
Posts: 552
Joined: 9-June 04
From: A place long since forgotten...
Member No.: 14572



QUOTE (SebastianG @ Aug 16 2005, 06:18 AM)
The mpeg2 specification not only contains a low sampling rate extension but also a multichannel extension.

Sebi
*
A multichannel extension that has never had an encoder implementation AFAIK smile.gif


--------------------
Nero AAC 1.5.1.0: -q0.45
Go to the top of the page
+Quote Post
rjamorim
post Aug 16 2005, 18:06
Post #7


Rarewares admin


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



QUOTE (DreamTactix291 @ Aug 16 2005, 01:47 PM)
A multichannel extension that has never had an encoder implementation AFAIK smile.gif
*


There is an MP2 encoder. Check RRW.


--------------------
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
DreamTactix291
post Aug 16 2005, 18:35
Post #8





Group: Members (Donating)
Posts: 552
Joined: 9-June 04
From: A place long since forgotten...
Member No.: 14572



Alright no MP3 implementation. The MP2 encoder sounds interesting though smile.gif


--------------------
Nero AAC 1.5.1.0: -q0.45
Go to the top of the page
+Quote Post
gasmann
post Aug 18 2005, 09:44
Post #9





Group: Members
Posts: 112
Joined: 18-August 05
Member No.: 23986



couldn't this be mp3pro, too? I mean if you play a mp3pro file in a non-mp3pro-compatible standard mp3 player a 44kHz file ends up in a 22kHz standard mp3 file. The Spectral Band Replication (or whatever its called tongue.gif ) will not be seen by a standard mp3 decoder and so there are no higher frequencies available even though they are in the mp3pro file.


--------------------
flac 1.2.1 -8 (archive) | aoTuVb5.7 -q 4 (pc, s1mp3)
Go to the top of the page
+Quote Post
bond
post Aug 19 2005, 13:16
Post #10





Group: Members
Posts: 881
Joined: 11-October 02
Member No.: 3523



mp3pro is not part of the official mp3 standard


--------------------
I know, that I know nothing (Socrates)
Go to the top of the page
+Quote Post
SebastianG
post Aug 19 2005, 13:42
Post #11





Group: Developer
Posts: 1317
Joined: 20-March 04
From: Göttingen (DE)
Member No.: 12875



though, it makes use of mpeg2 (half the sampling rate) layer 3 for the "compatibility layer"

Sebi
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: 20th April 2014 - 03:45