Listening Comparison 4
 

OK, I've given in to unrelenting popular demand and posted yet another
Listening Comparison.

**** simple this one, in each of the following 3 sets, which tracks sound
the better - the 01s or 02s?

(All files under 5 Mb)


http://www.apah69.dsl.pipex.com/keit...t1-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t1-track02.mp4



http://www.apah69.dsl.pipex.com/keit...t2-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t2-track02.mp4



http://www.apah69.dsl.pipex.com/keit...t3-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t3-track02.mp4

Listening Comparison 4
 

Not much in it.

Without an ABX (which I know you wouldn't care about anyway) difficult to
tell the difference.
Treble clearer on the 2s(?)

Btw, not seen an mp4 in a while! IIRC, isn't it a propietry format named
to dupe people into thinking it's the successor of mp3 (instead of mpro3)?
Maybe I've got my wires crossed.

With all this ripping maybe try this link
http://cdexos.sourceforge.net/downloads.php - dead easy little ripper that
supports the newer formats and IME gets data from scratched CDs after EAC
threw them out.


On Sun, 14 Dec 2003 21:32:56 -0000, Keith G wrote:


OK, I've given in to unrelenting popular demand and posted yet another
Listening Comparison.

**** simple this one, in each of the following 3 sets, which tracks sound
the better - the 01s or 02s?

(All files under 5 Mb)


http://www.apah69.dsl.pipex.com/keit...t1-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t1-track02.mp4



http://www.apah69.dsl.pipex.com/keit...t2-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t2-track02.mp4



http://www.apah69.dsl.pipex.com/keit...t3-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t3-track02.mp4







--
Jim H jh
@333
.org

Listening Comparison 4
 

Not much in it.

Without an ABX (which I know you wouldn't care about anyway) difficult to
tell the difference.
Treble clearer on the 2s(?)

Btw, not seen an mp4 in a while! IIRC, isn't it a propietry format named
to dupe people into thinking it's the successor of mp3 (instead of mpro3)?
Maybe I've got my wires crossed.

With all this ripping maybe try this link
http://cdexos.sourceforge.net/downloads.php - dead easy little ripper that
supports the newer formats and IME gets data from scratched CDs after EAC
threw them out.


On Sun, 14 Dec 2003 21:32:56 -0000, Keith G wrote:


OK, I've given in to unrelenting popular demand and posted yet another
Listening Comparison.

**** simple this one, in each of the following 3 sets, which tracks sound
the better - the 01s or 02s?

(All files under 5 Mb)


http://www.apah69.dsl.pipex.com/keit...t1-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t1-track02.mp4



http://www.apah69.dsl.pipex.com/keit...t2-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t2-track02.mp4



http://www.apah69.dsl.pipex.com/keit...t3-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t3-track02.mp4







--
Jim H jh
@333
.org

Listening Comparison 4
 

"Jim H" wrote in message


Not much in it.

Without an ABX (which I know you wouldn't care about anyway)
difficult to tell the difference.
Treble clearer on the 2s(?)


I obtained a MP3 plug-in for Winamp and used it to perform the conversion of
both Mp3 and Mp4 files to .wav files. I then checked them out for time and
level matching in Adobe Audition, and found them to be good. I then spent
several hours PCABXing, and frustrated myself with a lot of "random
guessing" type scores, even though at times I felt I was reliably hearing a
difference.

Since the MP4 (AAC) format has received a lot of favorable press, and some
of this music seems like the kind of stuff that makes some MP3 encoders do
bad things, I think the time was well-spent.

I conclude that MP4 does not have a day-and-night advantage over MP3. Thanks
Keith, for the stimulus to actually do the comparison.

Listening Comparison 4
 

"Jim H" wrote in message


Not much in it.

Without an ABX (which I know you wouldn't care about anyway)
difficult to tell the difference.
Treble clearer on the 2s(?)


I obtained a MP3 plug-in for Winamp and used it to perform the conversion of
both Mp3 and Mp4 files to .wav files. I then checked them out for time and
level matching in Adobe Audition, and found them to be good. I then spent
several hours PCABXing, and frustrated myself with a lot of "random
guessing" type scores, even though at times I felt I was reliably hearing a
difference.

Since the MP4 (AAC) format has received a lot of favorable press, and some
of this music seems like the kind of stuff that makes some MP3 encoders do
bad things, I think the time was well-spent.

I conclude that MP4 does not have a day-and-night advantage over MP3. Thanks
Keith, for the stimulus to actually do the comparison.

Listening Comparison 4
 

"Arny Krueger" wrote in message
...
"Jim H" wrote in message


Not much in it.

Without an ABX (which I know you wouldn't care about anyway)
difficult to tell the difference.
Treble clearer on the 2s(?)


I obtained a MP3 plug-in for Winamp and used it to perform the conversion
of
both Mp3 and Mp4 files to .wav files. I then checked them out for time and
level matching in Adobe Audition, and found them to be good. I then spent
several hours PCABXing, and frustrated myself with a lot of "random
guessing" type scores, even though at times I felt I was reliably hearing
a
difference.

Since the MP4 (AAC) format has received a lot of favorable press, and some
of this music seems like the kind of stuff that makes some MP3 encoders do
bad things, I think the time was well-spent.

I conclude that MP4 does not have a day-and-night advantage over MP3.
Thanks
Keith, for the stimulus to actually do the comparison.





OK, difficult to ignore a constructive, helpful and useful response.

My own initial feeling (in what was ostensibly a 128 Kbps CBR/MP3 vs.
110 -150 Kbps VBR/MP4 comparison) is that the MP4s sounded a little
'fresher' (more open in the treble?), but I haven't yet had the opportunity
to do this blind (using my own Electro-Acoustic Replay Scrutinizer), where
the tracks will be selected for me in random pairs......

Anyhoo, it don't end here! This file comparison was done at the approx. 5
Mb/track mark, but as it has been recently pointed out storage is becoming
cheaper, I want to ramp this up a notch to filesizes of about 7 Mb/track
which will allow me to try MP4s with a 160 - 250 Kbps VBR and also to bring
WMA files into the equation on an equal filesize basis, so if you feel
inclined suggest a more suitable type of music (artist, band or genre) and
I'll try to get as close as I can from the somewhat limited choice of, er,
'non-analogue original' music that is available to me.....

Listening Comparison 4
 

"Arny Krueger" wrote in message
...
"Jim H" wrote in message


Not much in it.

Without an ABX (which I know you wouldn't care about anyway)
difficult to tell the difference.
Treble clearer on the 2s(?)


I obtained a MP3 plug-in for Winamp and used it to perform the conversion
of
both Mp3 and Mp4 files to .wav files. I then checked them out for time and
level matching in Adobe Audition, and found them to be good. I then spent
several hours PCABXing, and frustrated myself with a lot of "random
guessing" type scores, even though at times I felt I was reliably hearing
a
difference.

Since the MP4 (AAC) format has received a lot of favorable press, and some
of this music seems like the kind of stuff that makes some MP3 encoders do
bad things, I think the time was well-spent.

I conclude that MP4 does not have a day-and-night advantage over MP3.
Thanks
Keith, for the stimulus to actually do the comparison.





OK, difficult to ignore a constructive, helpful and useful response.

My own initial feeling (in what was ostensibly a 128 Kbps CBR/MP3 vs.
110 -150 Kbps VBR/MP4 comparison) is that the MP4s sounded a little
'fresher' (more open in the treble?), but I haven't yet had the opportunity
to do this blind (using my own Electro-Acoustic Replay Scrutinizer), where
the tracks will be selected for me in random pairs......

Anyhoo, it don't end here! This file comparison was done at the approx. 5
Mb/track mark, but as it has been recently pointed out storage is becoming
cheaper, I want to ramp this up a notch to filesizes of about 7 Mb/track
which will allow me to try MP4s with a 160 - 250 Kbps VBR and also to bring
WMA files into the equation on an equal filesize basis, so if you feel
inclined suggest a more suitable type of music (artist, band or genre) and
I'll try to get as close as I can from the somewhat limited choice of, er,
'non-analogue original' music that is available to me.....

Listening Comparison 4
 

"Keith G" wrote in message ...

My own initial feeling (in what was ostensibly a 128 Kbps CBR/MP3 vs.
110 -150 Kbps VBR/MP4 comparison) is that the MP4s sounded a little
'fresher' (more open in the treble?), but I haven't yet had the opportunity
to do this blind (using my own Electro-Acoustic Replay Scrutinizer), where
the tracks will be selected for me in random pairs......

At 128 Kbps and below, formats such as Ogg Vorbis and AAC are clearly
better than MP3, specially using a good AAC implementation such as
Apple iTunes one. At 128 Kbps and over, there's another very good
performing contender called Musepack or MPC. At high bitrates, MP3 is
not that bad, specially if compared to Ogg Vorbis, but at around 160
Kbps, Ogg Vorbis and even more AAC, tend to still be better, and MPC
is probably the best with difference. At bitrates of 200 Kbps MPC is
the winner without doubt, achieving perceptual transparency with
virtually all kind of sounds, and of the formats left, probably only
AAC is still beter than MP3.

Listening Comparison 4
 

"Keith G" wrote in message ...

My own initial feeling (in what was ostensibly a 128 Kbps CBR/MP3 vs.
110 -150 Kbps VBR/MP4 comparison) is that the MP4s sounded a little
'fresher' (more open in the treble?), but I haven't yet had the opportunity
to do this blind (using my own Electro-Acoustic Replay Scrutinizer), where
the tracks will be selected for me in random pairs......

At 128 Kbps and below, formats such as Ogg Vorbis and AAC are clearly
better than MP3, specially using a good AAC implementation such as
Apple iTunes one. At 128 Kbps and over, there's another very good
performing contender called Musepack or MPC. At high bitrates, MP3 is
not that bad, specially if compared to Ogg Vorbis, but at around 160
Kbps, Ogg Vorbis and even more AAC, tend to still be better, and MPC
is probably the best with difference. At bitrates of 200 Kbps MPC is
the winner without doubt, achieving perceptual transparency with
virtually all kind of sounds, and of the formats left, probably only
AAC is still beter than MP3.

Listening Comparison 4
 

"KikeG" wrote in message
om...
"Keith G" wrote in message
...

My own initial feeling (in what was ostensibly a 128 Kbps CBR/MP3 vs.
110 -150 Kbps VBR/MP4 comparison) is that the MP4s sounded a little
'fresher' (more open in the treble?), but I haven't yet had the
opportunity
to do this blind (using my own Electro-Acoustic Replay Scrutinizer),
where
the tracks will be selected for me in random pairs......

At 128 Kbps and below, formats such as Ogg Vorbis and AAC are clearly
better than MP3, specially using a good AAC implementation such as
Apple iTunes one. At 128 Kbps and over, there's another very good
performing contender called Musepack or MPC. At high bitrates, MP3 is
not that bad, specially if compared to Ogg Vorbis, but at around 160
Kbps, Ogg Vorbis and even more AAC, tend to still be better, and MPC
is probably the best with difference. At bitrates of 200 Kbps MPC is
the winner without doubt, achieving perceptual transparency with
virtually all kind of sounds, and of the formats left, probably only
AAC is still beter than MP3.


Interesting. I've discounted MP4 for the moment on the grounds that it's a
bit of a red herring. I've also come to a bit of a conclusion on the MP3/WMA
front and have posted a couple more tracks to compare, if anyone is
interested. (Ain't like we're busy in here, or anything.....)


http://www.apah69.dsl.pipex.com/keit...t1-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t1-track02.wma

and

http://www.apah69.dsl.pipex.com/keit...t2-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t2-track02.wma


I've picked music to contrast with the earlier samples and would recommend
anyone to download them and burn an audio CDR so they can be flicked about
on an ordinary CDP. If anyone has got a 'sudden death' preference, I would
be interested to hear it......

Listening Comparison 4
 

"KikeG" wrote in message
om...
"Keith G" wrote in message
...

My own initial feeling (in what was ostensibly a 128 Kbps CBR/MP3 vs.
110 -150 Kbps VBR/MP4 comparison) is that the MP4s sounded a little
'fresher' (more open in the treble?), but I haven't yet had the
opportunity
to do this blind (using my own Electro-Acoustic Replay Scrutinizer),
where
the tracks will be selected for me in random pairs......

At 128 Kbps and below, formats such as Ogg Vorbis and AAC are clearly
better than MP3, specially using a good AAC implementation such as
Apple iTunes one. At 128 Kbps and over, there's another very good
performing contender called Musepack or MPC. At high bitrates, MP3 is
not that bad, specially if compared to Ogg Vorbis, but at around 160
Kbps, Ogg Vorbis and even more AAC, tend to still be better, and MPC
is probably the best with difference. At bitrates of 200 Kbps MPC is
the winner without doubt, achieving perceptual transparency with
virtually all kind of sounds, and of the formats left, probably only
AAC is still beter than MP3.


Interesting. I've discounted MP4 for the moment on the grounds that it's a
bit of a red herring. I've also come to a bit of a conclusion on the MP3/WMA
front and have posted a couple more tracks to compare, if anyone is
interested. (Ain't like we're busy in here, or anything.....)


http://www.apah69.dsl.pipex.com/keit...t1-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t1-track02.wma

and

http://www.apah69.dsl.pipex.com/keit...t2-track01.mp3

http://www.apah69.dsl.pipex.com/keit...t2-track02.wma


I've picked music to contrast with the earlier samples and would recommend
anyone to download them and burn an audio CDR so they can be flicked about
on an ordinary CDP. If anyone has got a 'sudden death' preference, I would
be interested to hear it......

Listening Comparison 4
 

"Keith G" wrote in message ...

Interesting. I've discounted MP4 for the moment on the grounds that it's a
bit of a red herring.

Some months ago there was a listening test over various codecs at 128
Kbps, performed by a multitude of people, using double-blind methods.
You can look at the results at he

http://audio.ciara.us/test/128extension/results.html

At the end of the page is the overall score of each codec. At the
beginning of the page there is a link to the codecs and options used.

Listening Comparison 4
 

"Keith G" wrote in message ...

Interesting. I've discounted MP4 for the moment on the grounds that it's a
bit of a red herring.

Some months ago there was a listening test over various codecs at 128
Kbps, performed by a multitude of people, using double-blind methods.
You can look at the results at he

http://audio.ciara.us/test/128extension/results.html

At the end of the page is the overall score of each codec. At the
beginning of the page there is a link to the codecs and options used.

Listening Comparison 4
 

On 18 Dec 2003 02:01:05 -0800
(KikeG) wrote:


Some months ago there was a listening test over various codecs at 128
Kbps, performed by a multitude of people, using double-blind methods.
You can look at the results at he

http://audio.ciara.us/test/128extension/results.html

What an appaling test. the bitrates are way off (at least the guy documents that)

only three of the codecs are nominally 128kbit, LAME is substantially lower and ogg somewhat higher.

if you look st the results knowing that, it shows the test up as useless.

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

Listening Comparison 4
 

On 18 Dec 2003 02:01:05 -0800
(KikeG) wrote:


Some months ago there was a listening test over various codecs at 128
Kbps, performed by a multitude of people, using double-blind methods.
You can look at the results at he

http://audio.ciara.us/test/128extension/results.html

What an appaling test. the bitrates are way off (at least the guy documents that)

only three of the codecs are nominally 128kbit, LAME is substantially lower and ogg somewhat higher.

if you look st the results knowing that, it shows the test up as useless.

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

Listening Comparison 4
 

"KikeG" wrote in message
m...
"Keith G" wrote in message
...

Interesting. I've discounted MP4 for the moment on the grounds that it's
a
bit of a red herring.

Some months ago there was a listening test over various codecs at 128
Kbps, performed by a multitude of people, using double-blind methods.
You can look at the results at he

http://audio.ciara.us/test/128extension/results.html

At the end of the page is the overall score of each codec. At the
beginning of the page there is a link to the codecs and options used.




Interesting, but not quite what I'm looking to compare (MP3 vs. ordinary
WMA) - thanks for posting anyway.

Listening Comparison 4
 

"KikeG" wrote in message
m...
"Keith G" wrote in message
...

Interesting. I've discounted MP4 for the moment on the grounds that it's
a
bit of a red herring.

Some months ago there was a listening test over various codecs at 128
Kbps, performed by a multitude of people, using double-blind methods.
You can look at the results at he

http://audio.ciara.us/test/128extension/results.html

At the end of the page is the overall score of each codec. At the
beginning of the page there is a link to the codecs and options used.




Interesting, but not quite what I'm looking to compare (MP3 vs. ordinary
WMA) - thanks for posting anyway.

Listening Comparison 4
 

Ian Molton wrote in message ...

What an appaling test. the bitrates are way off (at least the guy documents that)
if you look st the results knowing that, it shows the test up as useless.

The fact is that these codecs do achieve a average bitrate of 128 Kbps
when used to encode full albums. The actual bitrate used just for
these small test samples is not representative of realistic usage when
encoding full albums. That's the nature of VBR encoding. Please read
the presentation of the test (the first link at the page), this is
explained at there.

This issue was thoroughly discussed at the Hydrogenaudio forums before
the test was launched, and it was agreed that the final procedure used
was the most realistic way of calculating bitrates.

Listening Comparison 4
 

Ian Molton wrote in message ...

What an appaling test. the bitrates are way off (at least the guy documents that)
if you look st the results knowing that, it shows the test up as useless.

The fact is that these codecs do achieve a average bitrate of 128 Kbps
when used to encode full albums. The actual bitrate used just for
these small test samples is not representative of realistic usage when
encoding full albums. That's the nature of VBR encoding. Please read
the presentation of the test (the first link at the page), this is
explained at there.

This issue was thoroughly discussed at the Hydrogenaudio forums before
the test was launched, and it was agreed that the final procedure used
was the most realistic way of calculating bitrates.

Listening Comparison 4
 

On 18 Dec 2003 08:30:14 -0800
(KikeG) wrote:

The fact is that these codecs do achieve a average bitrate of 128 Kbps
when used to encode full albums. The actual bitrate used just for
these small test samples is not representative of realistic usage when
encoding full albums.

Pure nonscience.

if the average for the tracks is 128kbit, the avergae for the album is 128kbit and vice-versa

if you have some exceptionally hard to encode tracks it doesnt mean the other tracks should suffer in the comparison just to make it fair. and thats going to be different for ever album anyway.

either compare all at the same average bitrate for a given piece, or dont bother at all.

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

Listening Comparison 4
 

On 18 Dec 2003 08:30:14 -0800
(KikeG) wrote:

The fact is that these codecs do achieve a average bitrate of 128 Kbps
when used to encode full albums. The actual bitrate used just for
these small test samples is not representative of realistic usage when
encoding full albums.

Pure nonscience.

if the average for the tracks is 128kbit, the avergae for the album is 128kbit and vice-versa

if you have some exceptionally hard to encode tracks it doesnt mean the other tracks should suffer in the comparison just to make it fair. and thats going to be different for ever album anyway.

either compare all at the same average bitrate for a given piece, or dont bother at all.

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with ketchup.

Listening Comparison 4
 

Ian Molton wrote in message ...

Pure nonscience.

:D yeah right.

if the average for the tracks is 128kbit, the avergae for the album is
128kbit and vice-versa

But the samples used at the test are not even full tracks, are very
short pieces of music somewhat hard to encode. Full tracks will
average closer to 128 kbps. Go try yourself.

if you have some exceptionally hard to encode tracks it doesnt mean the other
tracks should suffer in the comparison just to make it fair. and thats going
to be different for ever album anyway.

Who says the other tracks (or parts of music) will suffer? If the
"hard" tracks don't suffer, thanks to bitrate increase, why would the
"easy" tracks would have to suffer? The target of VBR codecs is to
maintain quality, dynamically increasing bitrate if there's need for
it. 128 Kbps is the AVERAGE bitrate. This bitrate was calculated
averaging the result of a large number of albums. Nothing to to with
CBR, where 128 Kbps is a CONSTANT bitrate. Please inform yourself
about what VBR means.

either compare all at the same average bitrate for a given piece, or dont bother at all.

You are wrong, that would be highly unrealistic. If you can't
understand this, there's little I can do to help you.

Listening Comparison 4
 

Ian Molton wrote in message ...

Pure nonscience.

:D yeah right.

if the average for the tracks is 128kbit, the avergae for the album is
128kbit and vice-versa

But the samples used at the test are not even full tracks, are very
short pieces of music somewhat hard to encode. Full tracks will
average closer to 128 kbps. Go try yourself.

if you have some exceptionally hard to encode tracks it doesnt mean the other
tracks should suffer in the comparison just to make it fair. and thats going
to be different for ever album anyway.

Who says the other tracks (or parts of music) will suffer? If the
"hard" tracks don't suffer, thanks to bitrate increase, why would the
"easy" tracks would have to suffer? The target of VBR codecs is to
maintain quality, dynamically increasing bitrate if there's need for
it. 128 Kbps is the AVERAGE bitrate. This bitrate was calculated
averaging the result of a large number of albums. Nothing to to with
CBR, where 128 Kbps is a CONSTANT bitrate. Please inform yourself
about what VBR means.

either compare all at the same average bitrate for a given piece, or dont bother at all.

You are wrong, that would be highly unrealistic. If you can't
understand this, there's little I can do to help you.

Listening Comparison 4
 

On 22 Dec 2003 02:46:50 -0800
(KikeG) wrote:

Ian Molton wrote in message
...

Pure nonscience.

:D yeah right.

if the average for the tracks is 128kbit, the avergae for the album
is 128kbit and vice-versa

But the samples used at the test are not even full tracks, are very
short pieces of music somewhat hard to encode. Full tracks will
average closer to 128 kbps. Go try yourself.

You dont know they would be. the rest of the tracks may be substantially
easier or harder to encode, and thus the average bitrate would eb
significantly lower or higher.

The target of VBR codecs is to
maintain quality, dynamically increasing bitrate if there's need for
it. 128 Kbps is the AVERAGE bitrate.

Again, you have missed the point. VBR does NOT mean the average bitrate
is constant over a nominal period. It simply means the bitrate is not
constant, and there are (at least) two strategies in common use:

1) the one you (seem to be) describing, quality based VBR, where the
bitrate is the lowest possible to maintain a constant 'q' factor
(quality) throughout the track. This type does indeed use less bits for
easy areas and more on demand.

2) AVERAGE based VBR, which does the same as above, but keeps the
average, over a noominal period, as close to a specified value as
possible. thus any easy to encode parts of the track 'waste' bits, and
difficult parts may not get enough bits, or potentially can starve bits
from nearby portions of the track.

Strategy 2 is used where streaming is being used and a constant rate
bitstream is needed. Strategy 1 is used to keep filesize down without
compromising quality.

This bitrate was calculated averaging the result of a large number of
albums.

Assuming they were all encoded as VBR then whoever was doing the
encoding did an apalling job of matching the quality settings.

Nothing to to with CBR, where 128 Kbps is a CONSTANT bitrate.

Duh.

Please inform yourself about what VBR means.

I think its you that needs informing.

either compare all at the same average bitrate for a given piece, or
dont bother at all.

You are wrong, that would be highly unrealistic. If you can't
understand this, there's little I can do to help you.

If you had two hypothetical 'mp3 type' encoders that can do fixed and
variable bitrate, you should be comparing them at a fixed bitrate.
Variable bitrate encoding should be done by selecting the correct
bitrate for a 'frame' in the track based on quality, and thus in a fair
test, all encoders should use the same quality model for determining
quality.

--
Spyros lair: http://www.mnementh.co.uk/ |||| Maintainer: arm26 linux

Do not meddle in the affairs of Dragons, for you are tasty and good with
ketchup.

Listening Comparison 4
 

On 22 Dec 2003 02:46:50 -0800
(KikeG) wrote:

Ian Molton wrote in message
...

Pure nonscience.

:D yeah right.

if the average for the tracks is 128kbit, the avergae for the album
is 128kbit and vice-versa

But the samples used at the test are not even full tracks, are very
short pieces of music somewhat hard to encode. Full tracks will
average closer to 128 kbps. Go try yourself.

You dont know they would be. the rest of the tracks may be substantially
easier or harder to encode, and thus the average bitrate would eb
significantly lower or higher.

The target of VBR codecs is to
maintain quality, dynamically increasing bitrate if there's need for
it. 128 Kbps is the AVERAGE bitrate.

Again, you have missed the point. VBR does NOT mean the average bitrate
is constant over a nominal period. It simply means the bitrate is not
constant, and there are (at least) two strategies in common use:

1) the one you (seem to be) describing, quality based VBR, where the
bitrate is the lowest possible to maintain a constant 'q' factor
(quality) throughout the track. This type does indeed use less bits for
easy areas and more on demand.

2) AVERAGE based VBR, which does the same as above, but keeps the
average, over a noominal period, as close to a specified value as
possible. thus any easy to encode parts of the track 'waste' bits, and
difficult parts may not get enough bits, or potentially can starve bits
from nearby portions of the track.

Strategy 2 is used where streaming is being used and a constant rate
bitstream is needed. Strategy 1 is used to keep filesize down without
compromising quality.

This bitrate was calculated averaging the result of a large number of
albums.

Assuming they were all encoded as VBR then whoever was doing the
encoding did an apalling job of matching the quality settings.

Nothing to to with CBR, where 128 Kbps is a CONSTANT bitrate.

Duh.

Please inform yourself about what VBR means.

I think its you that needs informing.

either compare all at the same average bitrate for a given piece, or
dont bother at all.

You are wrong, that would be highly unrealistic. If you can't
understand this, there's little I can do to help you.

If you had two hypothetical 'mp3 type' encoders that can do fixed and
variable bitrate, you should be comparing them at a fixed bitrate.
Variable bitrate encoding should be done by selecting the correct
bitrate for a 'frame' in the track based on quality, and thus in a fair
test, all encoders should use the same quality model for determining
quality.

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