OGG versus MP3 Tests :)

[tfm]

Hi,

I just made some tests about VORBIS and MP3 :

I used first minute from "KOSHEEN - HIDE U (Single - Radio Edit)", because have at the begining, some specific sound.

- track was extracted from CD with "Exact Audio Copy v0.9 beta 4"
- for MP3, i used LAME.EXE from "lame-3.93.1.zip" (v3.92 ???)
- for OGG, i used OGGENC.EXE from "vorbis-tools v1.0" and
OGGDROPXPD.EXE.
- Spectrum Analisys was made with SOUND FORGE v6.0


Page with results is :
[removed]

Script for encode with LAME :
[removed]
Script for encode with OGG :
[removed]

[pacohaas]

you should probably check out some of the recommended settins for LAME, check the audio FAQ.

[tfm]

Hi,

... i don`t try to get BEST QUALITY from OGG or MP3.
I try to compare with the same (almoust) options.

- both ABR
- both the same Bitrate
- both (almoust) the same SamplingRate

... and see what freq. are still present in file after compression.


I don`t try to talk about HQ of one or other.
I try to get best audio from a given Bitrate.

[pacohaas]

Originally posted by tfm
I try to get best audio from a given Bitrate. yes, and with LAME 3.92, the correct command-line to get the best audio from a given bitrate is:

lame --alt-preset <bitrate>

Also, LAME's resampling algorithms aren't up to par with say, ssrc, so comparing a resampled mp3 to a ogg(which is better tuned for 48KHz anyhow) is not really a good comparison.

[tangent]

Test is fatally flawed in 2 ways.

1. You're not using the best settings for either encoder or even settings that your particular audience (I'm assuming DVD rip transcoding) will use.

2. You're comparing using graphical analysis which is completely useless as the results of graphic analysis has very little to do with actual audio quality.

For more ideas about how good audio quality tests are performed, you'll want to check out this few places

http://www.ff123.net
http://sjeng.sourceforge.net/audio/codecs.html

Or a search in the forums at
http://www.hydrogenaudio.org

[ChristianHJW]

LMAO ...

Reminds me of a friend who was always fine tuning his loudspeaker crossovers such that the impulse response coming back from them, measured with one of those PCI card based louspeaker measurement systems, would LOOK like the impulse on the input of his measurement amp.

It took me several weeks to convince him that the impulse response from a loudpspeaker can NEVER look like that under normal circumstances, because speakers can normally not reproduce DC components in signals ( :D ) and without such a DC component a Dirac impulse will never look like it does ..... he was very surprised when he wa upgrading his measurement system with a better software one day, and his system would show him the phase curve over frequency for his 'tuned' speakers ... sure looked like complete shit, some allpasses in there ( 180° shifts ) and in this case ( phase response ) you can believe your eyes and deduct how your system may sound if its not flat, or at least linear ;) ....

[tfm]

Hi,

I don`t compare compression for converting DVD audio ... only for CD extracted tracks.

My interests is in frequencyes present in file after coding.
Audio artifacts is another discussion.
Audio hearing test is not my goal.

Why ?

I work for a radio station. I develop a "radio automation system". At the moment, work with MP3, of course. I need to determine two aspects :

a) what codec to use for next YEARS (currently i use only MP3 320 CBR)
b) what codec to use for internet streaming (currently i use ASF at 24kbps) - for DialUp listeners.


I only intented to see what freq. are left off by codecs.

For archival purposes, my OGG at 500kbps is 1/3 in size from WAV.
But in that case, i use ADPCM instead.

For Internet listeners, artifacts, at lower bitrates, are present any codec i use. For that reason, i try to get more HIGHER FREQ. too. (like in ASF).
If i get a medium sound (20Hz to 6-8KHZ), it sounds like AM Radios. :)
I need more than that :)


Usable for my goal :
- MP3 :
:( problems with licencing. More in future to come, it seems.

:) many tools already made.
:) i already have specifications for this.
:) i already developed appz for this.
:) more of my coleagues already know how to work with MP3s.
(even that who call "Volume Icon in the Taskbar" - "That little funnel". :))) )

- OGG : ... testing at the moment.

:) access to sources.
:) 44.1 khz for lower bitrates too.


... at the moment, i see a bright future for me ... because it seems coz i neet to "abandon my work" and switch to OGG :)))

----
pacohaas :

lame --alt-preset <bitrate>

... ok, i will remade tests with this ... :)


... comparing a resampled mp3 to a ogg(which is better tuned for 48KHz anyhow) is not really a good comparison.

...Yes, i know that. In fact, at lower freq., i don`t know how to compare mp3s with oggs (because that offer possibility to work with 44-48 khz for lower bitrates too) ... :)

---
tangent :

1. You're not using the best settings for either encoder or even settings that your particular audience (I'm assuming DVD rip transcoding) will use.

... nope. I need to determinate best encoders settings to make 30000-40000 cd tracks to a compressed format.


2. You're comparing using graphical analysis which is completely useless as the results of graphic analysis has very little to do with actual audio quality.

... See up.

---

10x for feedback,

[tangent]

In which case you are still using the wrong encoder settings. You should be using --alt-presets for lame and simple -q for ogg vorbis.

If you intend to make comparisons of perceptual audio encoders as an employee of a radio station, you should at least try to be more professional and understand perceptual encoding and psychoacoustic effects first before making a comparison. Otherwise what you are doing is the equivilent of comparing the heights of two people by measuring their weight.

Graphical analysis is useless to compare codecs because:

1) The purpose of perceptual audio encoders is to take advantage of psychoacoustic effects (namely the masking effect and the absolute threshold of hearing) to get rid of frequencies which the human ear cannot hear. Just because an encoder isn't encoding a particular frequency doesn't mean that you can tell the difference between original and encoding.

2) You mentioned radio station. Assuming it's going to play the music over FM waves, you are already limited to ~15.5kHz lowpass.


P.S. For archival quality, there is no need to look any further. MPC (aka musepack) is what you are looking for.

[tfm]

Hi,

k, 10x for your feedback, only if i make a question, i learn (try and error - learn/listen to other)


:)

[pacohaas]

Originally posted by tangent
...what you are doing is the equivilent of comparing the heights of two people by measuring their weight.VERY well put!

[Sirber]

RealAudio is quite better than OGG and MP3 @ 32kbps and 64kbps. Give it a try!