MP2 vs MP3

[mysticgohan17]

at which bitrate for each of these would they be equal in sound qualiy. like would a 192kbit MP3 file be equal to a 224kbit MP2 file?

[txpharoah]

MP2 and MP3 just different formats. Each at same k would be same quality.

More or less. Just be sure the MP2 is 192k+ and the MP3 (for music) is 160k+ (128 is a bit low for accurate quality, though used a lot on pirate/bootleg MP3 trading).

[SaSi]

MP2 and MP3 just different formats. Each at same k would be same quality.

Not entirely accurate.

MP2 is shorthand for MPEG-2 Audio Layer II, while MP3 is shorthand for MPEG-2 Audio Layer III.

While both these subformats belong to the same syntax, Layer III introduces several encoding enhancements (not in the format itself but in the way the original source signal is processed) that provide better encoding quality.

A rule of thumb is that Layer I audio requires at least 224kbps for "acceptable" sound quality, Layer II reduces that to 192 or so while Layer III further reduces bitrate demands to 128kbps, to achieve comparable audio quality.

What "acceptable" means is a wide issue and one that has more than one correct answers, however the fact remains that the higher the encoding layer goes, the better audio quality is achieved with the same bitrate.

[mysticgohan17]

cleared up alot of stuff.

[sterno]

Another thing to remember is that if you are converting an already-compressed audio file to another compressed format you'll need a higher bitrate to retain the same quality.

[mysticgohan17]

Another thing to remember is that if you are converting an already-compressed audio file to another compressed format you'll need a higher bitrate to retain the same quality.

if i were using an audio cd as a source that wouldn't be a problem. i could use a wav that was compressed to two separate files (mp3 and mp2) and then compare quality.

[EddyH]

hold on, if the secret of mp3 lies in how the source audio is preprocessed before compressing, then conceivably similar processing could be applied to input audio to an mp2 codec to achieve just the same quality as an equal bitrate mp3 file? (now that would be cool)

or am i misunderstanding something / the original author is talking bull?

[SaSi]

hold on, if the secret of mp3 lies in how the source audio is preprocessed before compressing, then conceivably similar processing could be applied to input audio to an mp2 codec to achieve just the same quality as an equal bitrate mp3 file? (now that would be cool)

or am i misunderstanding something / the original author is talking bull?

There is no secrets in MP3 encoding.

The only pre-processing that takes place is a high cut filter that cuts off any frequency above 16kHz or 18kHz, to reduce audio that is considered inaudible, and if I'm correct, this is true for all three layers of encoding.

The secret is that both the layer III encoder and the decoder know "more" tricks in encoding and decoding the audio. MP3 (MPEG2 Layer III) is more demanding in CPU power both in encoding and decoding compared to Layer II and this is the reason it became so popular after the first Pentium machines came out. It encodes (and decodes) using all the layer II tricks plus some additional, demanding techniques. For this reason, equal bitrates produce slightly better audio with Layer III encoding.

[energy80s]

MP2 audio doesn't offer as good compression as MP3 audio, although it has better error correction so is often used for transmission. Therefore to get similar sound quality you have to up the bitrate. Yes, a 224kbps MP2 is similar to a 192kbps MP3 file. The best quality comes from ACC (advanced audio coding) which is twice as good as MP2, therefore a 128k ACC file (what is currently available for download on the Apple iTunes site) is the same as a 256k MP2 audio file, but only occupies half the file size.

[Donny661]

Ogg Vorbis is even better than AAC (in my opinion) and is hands down better than mp3.

I've heard than a 320kbps mp1 is equal to a 224kbps mp2 and is equal to a 128kbps mp3. That is just the opinion I've heard and I have never tried any comparisons myself between the mpeg audio layers.

[RabidDog]

:P actually APE is better than all these (quality wise) as it is lossless compression. sadly nothing supports it hardware wise except computers.
APE from monkeys audio. You can compress original wav files to 40% of their size and still play them back.. good for those with golden ears ,large disks and audigy titanium soundcards

[vitualis]

The only pre-processing that takes place is a high cut filter that cuts off any frequency above 16kHz or 18kHz, to reduce audio that is considered inaudible, and if I'm correct, this is true for all three layers of encoding.

I believe that is optional...

The secret is that both the layer III encoder and the decoder know "more" tricks in encoding and decoding the audio. MP3 (MPEG2 Layer III) is more demanding in CPU power both in encoding and decoding compared to Layer II and this is the reason it became so popular after the first Pentium machines came out. It encodes (and decodes) using all the layer II tricks plus some additional, demanding techniques. For this reason, equal bitrates produce slightly better audio with Layer III encoding.

I don't know the details but the above is mostly right. Layer III encoding I believe divides the audio spectrum into more bands than Layer II encoding.

Layer III is generally more efficient than Layer II encoding at the same bitrate.

When the internet was young and MP3 was just out (i.e., BEFORE Winamp became popular), it was stated back then that although MP3 was more efficient than MP2, that at high bitrates, MP2 gave better fidelity. This probably is no longer true with modern encoders and this belief probably came about because MP2 was mature while MP3 encoders were still far from optimised.

Regards.

[vitualis]

...224kbps mp2 and is equal to a 128kbps mp3.

Definitely not. 224 kbit/s MP2 gives excellent audio quality and fidelity. If anything, it is probably close to 192 kbit/s MP3...

Regards.

[energy80s]

Yeah, 224k MP2 is just a bit below 192k MP3 in the audio stakes. It's when you go to ACC that you can halve the bitrate and still achieve the same quality as MP2.

[jeex]

MP3 is shorthand for MPEG-2 Audio Layer III.

i'm pretty sure its mpeg-1, not mpeg-2

[SaSi]

MP3 is shorthand for MPEG-2 Audio Layer III.

i'm pretty sure its mpeg-1, not mpeg-2

Actually, you may be right

The original MPEG-1 document (11172) comprised of 5 parts, part 3 of which was audio encoding. All Layers I ~ III were defined there.

The MPEG-2 standard (13818) has enhanced the definition of the audio part, with two notable additions:
a. 3 additional sampling frequencies (16kHz, 22.05kHz and 24kHz)
b. Multichannel audio. In addition to 2 channel stereo, MPEG-2 audio defines optional audio channels (5) that represent a central Low frequency enhancement channel, two front audio channels plus 2 surround ones. Not the same as Dolby 5.1

Since MPEG-2 enhances audio quality by adding 3 additional sampling frequencies, one can assume that an encoder that cut's off anything above 16kHz is not MPEG-2. I've seen some encoding programs that have a high frequency cut option. I guess that this is the differentiator between MPEG-1 and MPEG-2 compliant streams.

So, let me rephrase myself: MP3 stands for MPEG Audio Layer III

[vitualis]

MP3 is "MPEG Audio, Layer 3".

It was originally MPEG-1 Layer 3 audio and when MPEG-2 came around, it added some additional abilities (as listed above).

Regards.

[energy80s]

Just remember that the MP2 audio we use is actually MPEG1 Layer 2 and MP3's are really MPEG1 Layer 3 audio files.

[neroman00]

I use AVS VIDEO CONVERTER

My source input (original) file AUDIO CODEC is MPEG-2/4 Audio.


Which audio codec should I choose in order to get equal or better audio quality to my output (converted) file?

mp2 OR mp3 OR MPEG-2/4 Audio OR PCM



Please advive

[_Al_]

for avi container (DivX and XviD) use mp3 audio
for mp4 container (video H.264) use AAC audio
for mpeg2 container use AC3 audio (or mp2)

it is bitrate that will guarantee certain quality, just use 192 or 256 kbps and you are fine

[jagabo]

I use AVS VIDEO CONVERTER

My source input (original) file AUDIO CODEC is MPEG-2/4 Audio.


Which audio codec should I choose in order to get equal or better audio quality to my output (converted) file?

mp2 OR mp3 OR MPEG-2/4 Audio OR PCM



Please advive

PCM will give you equal quality. All the rest will give you less quality because your recompressing with lossy codecs. If you don't want to lose quality it's best to just remux the audio.

I'm surprise nobody is complaining that you revived an 11 year old thread for this question.

[neroman00]

for avi container (DivX and XviD) use mp3 audio
for mp4 container (video H.264) use AAC audio
for mpeg2 container use AC3 audio (or mp2)

it is bitrate that will guarantee certain quality, just use 192 or 256 kbps and you are fine

Thanks a lot _Al_

[neroman00]

I use AVS VIDEO CONVERTER

My source input (original) file AUDIO CODEC is MPEG-2/4 Audio.


Which audio codec should I choose in order to get equal or better audio quality to my output (converted) file?

mp2 OR mp3 OR MPEG-2/4 Audio OR PCM



Please advive

PCM will give you equal quality. All the rest will give you less quality because your recompressing with lossy codecs. If you don't want to lose quality it's best to just remux the audio.

I'm surprise nobody is complaining that you revived an 11 year old thread for this question.

Many thanks for your answer
Sorry for that. I've just google and that's why I found an old thread.

[hogger129]

If you have a lossless stream, compress that down to AAC at 160k or MP3 at 192k. That's if you're using stereo. For surround, use AC3 at 384, 448 or 640, depending on if you can tell a difference between them.

[jagabo]

Of course, 99 percent of people who say they want "no quality loss" really mean they want "not much quality loss". In that case you can use AC3, MP3, or AAC at moderate bitrates.

[pandy]

MPEG 1/2 Layer II audio usually provide less problems with difficult sound as it should not introduce pre and post ringing (fast transients) - thus sometimes it can be better than all more complex, DCT based codecs (AAC, MP3, AC3 etc).
There is only one codec based on Layer II - MPC or Musepack http://en.wikipedia.org/wiki/Musepack which seem to be highest quality lossy codec available today.

[Mephesto]

MP2 I think is still used in radio broadcasting. I use MP2 sometimes not for the compression/quality but for the kind of artifacts the compression produces makes some audio sound better to me.

In one listening test I did years ago I vaguely recall rating MP2 at the same bitrate to be a bit better quality than MP3. That was hard to explain.

EDIT: I found it.

ABC/HR Version 1.0, 6 May 2004
Testname: Windmill AAC/MP3/MP2 test 44/32KHz

1L = C:\Documents and Settings\Admin\wm64(32)mp4.wav
2L = C:\Documents and Settings\Admin\wm64mp3.wav
3L = C:\Documents and Settings\Admin\wm112mp3.wav
4R = C:\Documents and Settings\Admin\wm64mp4.wav
5R = C:\Documents and Settings\Admin\wm96mp3.wav
6R = C:\Documents and Settings\Admin\wm128mp3.wav
7L = C:\Documents and Settings\Admin\wm128mp2.wav
8R = C:\Documents and Settings\Admin\wm64(32)mp3.wav

---------------------------------------
General Comments:

---------------------------------------
1L File: C:\Documents and Settings\Admin\wm64(32)mp4.wav
1L Rating: 4.8
1L Comment: Very slight pre-echo on the percussion. Wouldn't be noticed without focusing on the percussion and ignoring the rest of the audio.
---------------------------------------
2L File: C:\Documents and Settings\Admin\wm64mp3.wav
2L Rating: 2.5
2L Comment: Really washed out.
---------------------------------------
3L File: C:\Documents and Settings\Admin\wm112mp3.wav
3L Rating: 3.3
3L Comment: Smearing not as severe as sample2. Tolerable.
---------------------------------------
4R File: C:\Documents and Settings\Admin\wm64mp4.wav
4R Rating: 4.0
4R Comment: Slight distortion on the percussion, like sample1 but somewhat worse, and the crystalline highs near the end badly distorted. Artifact of SBR.
---------------------------------------
5R File: C:\Documents and Settings\Admin\wm96mp3.wav
5R Rating: 3.3
5R Comment: Sounds the same as sample3.
---------------------------------------
6R File: C:\Documents and Settings\Admin\wm128mp3.wav
6R Rating: 3.3
6R Comment: The same...
---------------------------------------
7L File: C:\Documents and Settings\Admin\wm128mp2.wav
7L Rating: 4.5
7L Comment: similar pre-echo effect as sample1 but with the crystalline highs distorted as well.
---------------------------------------
8R File: C:\Documents and Settings\Admin\wm64(32)mp3.wav
8R Rating: 3.0
8R Comment: Better than sample2 but worse than the others.
---------------------------------------
ABX Results:
Original vs C:\Documents and Settings\Admin\wm64(32)mp4.wav
    26 out of 33, pval < 0.001
Original vs C:\Documents and Settings\Admin\wm112mp3.wav
    10 out of 10, pval < 0.001
Original vs C:\Documents and Settings\Admin\wm128mp2.wav
    16 out of 22, pval = 0.026

I should do a serious comparison of MP2 and MP3 sometime. This test that I did makes no sense.

EDIT2: I just realized this thread is from 2003, holy shit. No wonder the OP has a DBZ name. Everybody was so into that back then. Even if the rampant fanboyism at the time pissed me off, they were good old times. Hell of a lot better than today.

[pandy]

MP2 I think is still used in radio broadcasting. I use MP2 sometimes not for the compression/quality but for the kind of artifacts the compression produces makes some audio sound better to me.

In one listening test I did years ago I vaguely recall rating MP2 at the same bitrate to be a bit better quality than MP3. That was hard to explain.

I should do a serious comparison of MP2 and MP3 sometime. This test that I did makes no sense.

EDIT2: I just realized this thread is from 2003, holy shit. No wonder the OP has a DBZ name. Everybody was so into that back then. Even if the rampant fanboyism at the time pissed me off, they were good old times. Hell of a lot better than today.

Yes, this is like a necroposting but anyway - people still searching for best lossy codec, they go for 320kbps mp3 where in fact with this bitrate mp2 will do better especially on some difficult sounds and musepack will perform probably even better.
I would say that for above 192kbps mp2 will probably sounds better than mp3.

[Cornucopia]

MP2 still used in broadcasting and in certain digital tape acquisition formats (HDV, ProHD, MicroMV, a few others).

@pandy, at that high bitrate, they OUGHT to all 3 (MP1, MP2 & MP3) be sonically transparent (aka indistinguishable from uncompressed/LPCM to the great majority of listeners). More on that soon...
BTW, MP2 is also a DCT-type codec. And Musepak isn't the only extant realization of it, there is still TooLame (or its variant, TwoLame).

Scott

[El Heggunte]

pandy is right --- MP3 was designed to NOT suck at 128kbps, not to be "always better" than MP2.

(even though it often keeps sucking at 128kbps )

If storage space is not a problem, then I do recommend MP2 @ 384kbps.