VBR bit rates

When the VBR option is selected in CDex it gives you a choice for the min
and max bitrates. When I tried 40K and 320K respectively the file size was
similar to a track encoded at 160K. Can't hear much difference in quality.

What would the advantage be(if any) of doing it this way, or should I be
selecting different min and maxes?

Jim.

Jim Murray wrote:
> When the VBR option is selected in CDex it gives you a choice for the
> min and max bitrates. When I tried 40K and 320K respectively the file
> size was similar to a track encoded at 160K. Can't hear much
> difference in quality.


Are you saying you can't hear much difference in quality between 40kbps MP3
and 320kbps MP3? What equipment are you playing the files back on? If you're
playing the tracks through a crappy sound card and crappy PC speakers then
that is about the worst playback system you could imagine...

Burn a CD with tracks that are encoded at different bit rates and then play
the tracks back on a hi-fi system and if you can't hear much difference in
quality between 40kbps and 320kbps MP3 then you should get your hearing
checked out, seriously.


> What would the advantage be(if any) of doing it this way, or should
> I be selecting different min and maxes?


VBR (variable vit rate) allows smaller file sizes for a given level of audio
quality compared to CBR (constant bit rate) or ABR (average bit rate). It
works by assessing what bit rate to use on a frame-by-frame (an MP3 frame
lasts a few milliseconds) so that easy to encode frames can be encoded with
a lower bit rate, and more difficult to encode frames can be encoded with a
higher bit rate, so the bit rate is optimised for a given level of audio
quality.

I use Razor Lame to encode MP3:

http://www.dors.de/razorlame/index.php

because it has a set of VBR, CBR and ABR presets that set the encoder up
with parameters that were selected by knowledgable people in the internet
audio coding community. To use the presets you just click the Lame icon
then:

Load Options => Presets => VBR => then select one of the presets files in
that folder and click Open.

If you can't tell the difference between 40kbps and 320kbps then the VBR
Standard.rlo preset file would be the best choice for you. I use the VBR
Extreme.rlo preset, which is overkill, but memory and CD-Rs are very cheap
and I just prefer to have a very high chance of the encoding having high
audio quality while still taking advantage of the better compression
performance that VBR allows.


--
Steve - http://www.digitalradiotech.co.uk/ - Digital Radio News & Info

DAB sounds worse than Freeview, digital satellite, cable, broadband
internet and FM

"Jim Murray" <jimmurray@ukonline.co.uk> wrote in message news:<brneul$noi$1@kermit.esat.net>...
> When the VBR option is selected in CDex it gives you a choice for the min
> and max bitrates. When I tried 40K and 320K respectively the file size was
> similar to a track encoded at 160K. Can't hear much difference in quality.
>
> What would the advantage be(if any) of doing it this way, or should I be
> selecting different min and maxes?
VBR is superior because segments of the song that do not need a high
fidelity use a lower bitrate, and areas of greater importance get the
higher. It really depends of the song. I'd stick with VBR, it will
save a considerable amount of space, espically if your a heavy ripper.

Cheers,
John Dziurlaj

Obviously I can hear a difference between 160K and 40K. What I mean is that
within CDex you can choose upper and lower limits for VBR to use. I tried
320K and 40K as a trial and as I say the file size was similar to encoding
at 160K constant. I was really looking for some advice re these upper amd
lower limits. I'll download Razorlame and have a play, sounds like it could
be setup for VBR with a more useful set of options.

Having said all that when I play tracks encoded at 160K constant in my car
player and then play the original audio CD I can't really hear any
difference between them. I'm happy with the quality, just trying to get a
smaller file size. Thanks for all the help,

Jim.

"the real DAB sounds worse than FM" <email_me@via_my_website.co.uk> wrote in
message news:bTDFb.242$Eu.268426@newsfep1-win.server.ntli.net...
> Jim Murray wrote:
> > When the VBR option is selected in CDex it gives you a choice for the
> > min and max bitrates. When I tried 40K and 320K respectively the file
> > size was similar to a track encoded at 160K. Can't hear much
> > difference in quality.
>
>
> Are you saying you can't hear much difference in quality between 40kbps
MP3
> and 320kbps MP3? What equipment are you playing the files back on? If
you're
> playing the tracks through a crappy sound card and crappy PC speakers then
> that is about the worst playback system you could imagine...
>
> Burn a CD with tracks that are encoded at different bit rates and then
play
> the tracks back on a hi-fi system and if you can't hear much difference in
> quality between 40kbps and 320kbps MP3 then you should get your hearing
> checked out, seriously.
>
>
> > What would the advantage be(if any) of doing it this way, or should
> > I be selecting different min and maxes?
>
>
> VBR (variable vit rate) allows smaller file sizes for a given level of
audio
> quality compared to CBR (constant bit rate) or ABR (average bit rate). It
> works by assessing what bit rate to use on a frame-by-frame (an MP3 frame
> lasts a few milliseconds) so that easy to encode frames can be encoded
with
> a lower bit rate, and more difficult to encode frames can be encoded with
a
> higher bit rate, so the bit rate is optimised for a given level of audio
> quality.
>
> I use Razor Lame to encode MP3:
>
> http://www.dors.de/razorlame/index.php
>
> because it has a set of VBR, CBR and ABR presets that set the encoder up
> with parameters that were selected by knowledgable people in the internet
> audio coding community. To use the presets you just click the Lame icon
> then:
>
> Load Options => Presets => VBR => then select one of the presets files in
> that folder and click Open.
>
> If you can't tell the difference between 40kbps and 320kbps then the VBR
> Standard.rlo preset file would be the best choice for you. I use the VBR
> Extreme.rlo preset, which is overkill, but memory and CD-Rs are very cheap
> and I just prefer to have a very high chance of the encoding having high
> audio quality while still taking advantage of the better compression
> performance that VBR allows.
>
>
> --
> Steve - http://www.digitalradiotech.co.uk/ - Digital Radio News & Info
>
> DAB sounds worse than Freeview, digital satellite, cable, broadband
> internet and FM
>
>