Re: Understanding and comparing compression formats

Gary Wood Thu, 12 May 2005 12:23:37 -0700

Hi Kevin. But then, isn't the manual saying that in order to avoid bad choices, we should use the 64 kbps setting with vbr? ----- Original Message ----- From: "Kevin Lloyd" <[EMAIL PROTECTED]> To: "PC audio discussion list. " <Pc-audio@pc-audio.org> Sent: Thursday, May 12, 2005 2:27 PM Subject: Re: Understanding and comparing compression formats

I think you've just about summed it up there Daniel.
I wouldn't use a floor of less than 128kbps for music but here's the info
from the manual explaining the differences:
Bitrate Options:
There are three types of bitrate options that you can specify for each the
encoder (although some encoders may not allow any options).
1) Constant Bitrate (CBR)
This is the default encoding mode, and also the most basic. In this mode,
the  bitrate will be the same throughout the whole file.  So, a second of
audio from one part of the file takes just as much disk space as a second
from any other part of that file -- regardless of whether either part is
silence, acoustically simple, or quite complex.  This means that you are
likely to hear distortion more in the complex parts than in the simple
parts.  The advantage of CBR formats is that even older players understand
them, and that you can reliably predict the file size from the duration of
the sound (or vice versa).
2) Average Bitrate (ABR)
In this mode, you tell the encoder to aim for an average bitrate that you specify, skimping on the simpler parts of the music, and using higher bitrates for the parts of your music that are more complex. The result will be of higher quality than you'd get in a CBR encoded file of the same size. This mode is highly recommended over CBR. This encoding mode is similar to VBR.
3) Variable bitrate (VBR)
In this mode, you say what level of quality you want in the output file, and the encoder compresses each second as best it can to get just that level of quality -- using less information to represent simpler parts of the song, and more information to represent the more complex parts. However, this mode relies heavily on the encoder's model of how you perceive quality, and could lead to a few "bad choices" in the encoding process. If possible, you may want to specify a minimum bitrate (e.g., 64 Kbps) to avoid those potential errors.
Kevin E-mail: [EMAIL PROTECTED] ----- Original Message ----- From: "Yardbird" <[EMAIL PROTECTED]> To: "PC audio discussion list. " <Pc-audio@pc-audio.org> Sent: Thursday, May 12, 2005 3:25 PM Subject: Re: Understanding and comparing compression formats

Just one thing, an example of the confusing nature of the manual. I
reread
that section a couple of times, and it doesn't seem to be actually
recommending setting a floor of 64.  There's some unspoken implication
that
some user may neglect to set any floor (minimum rate) at all.  It's not
explain why so low a rate as 64 would be useful or, more to what seems to
bee their point, necessary for heading off some sort of problem.  And,
again, it seems to be recommend average bit rate, but if you read that
over
a couple of time, at least this is my impression, they're implying that
variable bit rate, intelligently used, is the highest-quality approach.
But
all they say is that variable bit rate is best, then imply without
explaining that it's perhaps too sophisticated for some users and that
it's
easy to make a fatal mistake with it. I forget the exact wording, but
it's
simply not that coherent.
My impression at this point is that Kevin's explanations have been a lot more complete and a lot more coherent, and that's allowed me to figure out things that it seems the manual thinks it's saying but actually isn't.
In other words, I think it's saying "Average bit rate is a more refined
method than the stable bit rate, just so you remember not to set it so as
to
allow the bit rate to drop too low for any fidelity at all. But if you're careful, we'd actually tell you to use variable bit rate. lone m ----- Original Message ----- From: "Gary Wood" <[EMAIL PROTECTED]> To: "PC audio discussion list. " <Pc-audio@pc-audio.org> Sent: Wednesday, May 11, 2005 12:37 PM Subject: Re: Understanding and comparing compression formats

The manual states that the floor should be at 64 kbps. It sounds to me
like
it suggests going to vbr-abr. I'm trying to learn this stuff too. I'm
also
wondering what advantage there is to using the default vbr settings is. ----- Original Message ----- From: "Yardbird" <[EMAIL PROTECTED]> To: "PC audio discussion list. " <Pc-audio@pc-audio.org> Sent: Tuesday, May 10, 2005 4:07 PM Subject: Re: Understanding and comparing compression formats

> Thanks for explaining this. One more question about settings: > > I've learned from you how to make variable bit rate settings. Now, if > I > wish to try the average bit rate approach described in the manual, I > wonder > if I've discovered the way to set it for that. There isn't any button
or
> anything for doing this, so I poked around in the combo box list of
> various
> variable bit rate types.  First you have Disabled, then you have the
> default
> one, I guess that's what you're expected to use normally.
>
> Then you have a couple of variations whose names I don't understand.
And
> then, last on the list, is an option written as "VBR -ABR!" could this
be
> the choice that sets the encoder to use an average bit rate, as a
sub-type
> of "variable bit rate?"  Does anyone know?
>
> this program, though the price is right and the operation fairly simple
to
> navigate with a screen reader, is pretty bad in terms of how things are
> named and how the documentation is written.  I mean, it truly makes no
> sense
> at time.  It doesn't say, for instance, how to set VBR or ABR despite
> discussing them, and I see it's given one reader the opposite idea of
what
> it meant by cautioning against not using a floor setting. Same for the
on
> the fly explanation. It starts by saying one thing, then reverses
itself
> not out of intention but just because the writing is confused, and no
one
> edited it for clarity.
>
> I believe your own explanation of the on the fly deal sounded right.
I've
> noticed that ripping takes much longer when you uncheck it, so I assume
> this
> is because those operations I'm hearing tracked by the progress bar
> involve
> a first one that writes the track to an image, as you put it, and then
it
> converts that to an .mp3. But honestly, this stuff wouldn't be so hard
if
> the interface and documentation were a little better done.
>
> I know, beggars can't be choosers.  So step on my pencil cup and smash
my
> blues guitar.  But still.
>
> Okay, so what about the ABR setting?  Is that how you'd make it?  and
then
> do you still set a minimum and maximum for it to work with? > > thanks, guys. > coencodr fr > ----- Original Message ----- > From: "Kevin Lloyd" <[EMAIL PROTECTED]> > To: "PC audio discussion list. " <Pc-audio@pc-audio.org> > Sent: Tuesday, May 10, 2005 11:27 AM > Subject: Re: Understanding and comparing compression formats > > > Hi. > > There was a full version of CDEX released after this beta but > unfortunately > version 1.51 didn't work on many peoples machines and so the beta lived > on. > > Regards. > > Kevin > E-mail: [EMAIL PROTECTED] > ----- Original Message ----- > From: "Yardbird" <[EMAIL PROTECTED]> > To: "PC audio discussion list. " <Pc-audio@pc-audio.org> > Sent: Sunday, May 08, 2005 9:03 PM > Subject: Re: Understanding and comparing compression formats > > >> Ah, so the Control A select all works, even though control homeand >> then >> select to end didn't? Interesting. In other such situations, often > control >> A won't work, but if you go to the top or bottom of an area and select > home >> or select end, that will copy all. ah, I know what it is I'm thinking >> of. >> The General or Details tabs of the properties display for an Outlook > Express >> message. >> >> Okay. I'll look again... >> One more thing about the version of CdEx. How come it's a Beta
version?
>> Isn't there going to be a final version released? >> >> ----- Original Message ----- >> From: "Kevin Lloyd" <[EMAIL PROTECTED]> >> To: "PC audio discussion list. " <Pc-audio@pc-audio.org> >> Sent: Sunday, May 08, 2005 12:27 PM >> Subject: Re: Understanding and comparing compression formats >> >> >> I use that version of CDEX as I think most people on the list do.
There
> is >> actually an updated version 1.6 available now but I'm not sure what >> the > new >> features are. >> >> It's true that when you hit enter on a help topic, JAWS will start >> reading >> the page. You can't use your PC cursor to read the page back but you
can
>> use the JAWS cursor to do so. Alternatively, use control + A to >> select > and >> control + C to copy and paste into a word document. This does work >> and >> here's the CDEX introduction copied in exactly that way. >> >> Introduction >> >> >> This document describes CDex, a utility for extracting sound files >> from > CDs >> in your CD-ROM drive, and for converting WAV files into several other >> (compressed) formats, like the popular MP3 format. >> >> The latest version of CDex can be downloaded from: >> http://www.cdex.n3.net >> >> System Requirements >> Status of CDex >> Acknowledgements >> Change log >> >> >> >> Kevin >> E-mail: [EMAIL PROTECTED] >> ----- Original Message ----- >> From: "Yardbird" <[EMAIL PROTECTED]> >> To: "PC audio discussion list. " <Pc-audio@pc-audio.org> >> Sent: Sunday, May 08, 2005 8:14 PM >> Subject: Re: Understanding and comparing compression formats >> >> >> > One more thing: I just opened the copy of CdEx on my computer and >> attempted >> > to study the help file topics about things I need to learn. But >> > even >> though >> > the topic list is set up like a tree view, and I can navigate it >> > fine > and >> > open books or topics to arrow to their sub topics, when I hit Enter, >> > I'm >> > taken to a page that >> > 1. starts reading audotmatically in Jaws if I don't touch the >> > keyboard, >> but >> > can't be read deliberately with the arrow keys and Jaws reading >> keystrokes. >> > I thought maybe I could compensate by selecting and copying each > topics's >> > text to the clipboard and pasting into a text editor to read, but my >> attempt >> > to do this also failed, for some reason. >> > >> > Also, the text seems incomplete, from what I can figure out, like
only
>> topic
>> > headings are given but then there's no actual writing beyond that.
>> >
>> > 2.  I checked my version of CdEx, and I wonder if it's not really
what
>> > I >> > ought to be using if I want to have the latest configuration and >> > more >> usable >> > or fully written help documentation. I have version 1.51 Beta. A > friend >> > put it on my system, saying it's what he uses. But is this out of >> > date? >> If >> > so, where do I go to download the latest version of CdEx? >> > >> > thanks. >> > >> > ----- Original Message ----- >> > From: "Kevin Lloyd" <[EMAIL PROTECTED]> >> > To: "PC audio discussion list. " <Pc-audio@pc-audio.org> >> > Sent: Sunday, May 08, 2005 10:53 AM >> > Subject: Re: Understanding and comparing compression formats >> > >> > >> > Hi Daniel. >> > >> > CDEX will allow you to use a number of encoders to rip your music >> > and >> allow >> > you to use constant or variable bit rates. The WMA format is
available
>> but
>> > not all bit rates are supported for the version of the encoder
>> > included.
>> >
>> > Saying that, the default Lame encoder is regarded as one of the best
>> > MP3
>> > encoders around and in comparison tests I've done myself and read
>> > about,
>> it
>> > out performs WMA with most music genres.
>> >
>> > With regards to your question on burning the compressed MP3 or WMA
>> > files
>> to
>> > CD, well, you have the choice when burning to either create an audio
CD
>> for
>> > play in a standard CD player which will convert the compressed file
>> > into
>> WAV
>> > and then CDDA or you can burn the files to a data CD which will burn
> them
>> > exactly as they are on your hard drive.  That is, compressed.  There
>> > are
>> > increasing numbers of players on the market now, both portable and
> genuine
>> > hi-fi, that will play these data CD's with your MP3 music.  This
means
> you
>> > could have 10 albums or more on a single disc.  Kelly's point was
> exactly
>> > this that MP3 is still the most popular compressed format and most
well
>> > supported. You wouldn't want to rip a collection of CD's into WMA
and
>> find
>> > that you couldn't play them on anything else but your computer.
Maybe
> you >> > might now but chances are you'll want to take them with you at some > point >> > and want to invest in a portable player. Having them ripped into >> > MP3 > will >> > give you a much greater choice of player when that day comes. >> > >> > Regards. >> > >> > Kevin >> > E-mail: [EMAIL PROTECTED] >> > ----- Original Message ----- >> > From: "Yardbird" <[EMAIL PROTECTED]> >> > To: "PC audio discussion list. " <Pc-audio@pc-audio.org> >> > Sent: Sunday, May 08, 2005 2:17 AM >> > Subject: Re: Understanding and comparing compression formats >> > >> > >> > > Hi Kelly, >> > > thanks for responding. I have a copy of CdEx, though I forget the >> > version. >> > > But it doesn't offer any .wma possibilities at all, only .mp3 and > .wav. >> > > Does this mean I have an old version of it? Someone else loaded >> > > it > onto >> > my >> > > system for me. If I can update and see a more comprehensive array
of
>> > > compression options, that'd be reassuring.
>> > >
>> > > Also, I confess I don't understand about wither a compressed file
can
>> play
>> > > on a CD player:  From what I've learned so far, I have the
impression
>> that >> > > if you burn an .mp3 or other compressed music file to a CD, it >> > > will >> > > be >> > > converted, either manually or, in some programs, automatically, to
a
>> .wav >> > > file to be burned. Isn't this so? If it is, then what does it >> > > matter >> > > whether the file on your hard drive is .mp3 or .wma? >> > > >> > > Please explain further. I'm educating myself with your help. >> > > thanks, >> > > Daniel >> > > >> > > ----- Original Message ----- >> > > From: "Kelly Pierce" <[EMAIL PROTECTED]> >> > > To: "PC audio discussion list. " <Pc-audio@pc-audio.org> >> > > Sent: Saturday, May 07, 2005 3:28 PM >> > > Subject: Re: Understanding and comparing compression formats >> > > >> > > >> > > the options you mentioned with Windows media ripping are also > available >> in >> > > ripping MP3s with CDEX. remember it is in Microsoft's interest to > make >> > > windows Media appear to be a much more attractive experience than
the
>> > > infinitely portable and compatible MP3 format. With MP3 encoding, > files >> > can >> > > be encoded on various levels of quality, with fixed or variable >> > > bit >> rates >> > in >> > > full stereo. >> > > >> > > One thing to consider is the likelihood that the files you rip can
be
>> > played >> > > on other people's computers with different kinds and versions of >> software >> > > and on portable devices in the present and future. many CD >> > > players > can >> > play >> > > MP3 files but only a fraction of these can also play Windows Media >> files. >> > > to verify this, just go to bestbuy.com and review the portable CD >> players >> > > available for sale. Most play MP3 files but only one can also >> > > play >> > windows >> > > Media files as well. >> > > >> > > I encode most of the music I rip in MP3 at 256 bit in full stereo
at
> the >> > > very highest quality. >> > > >> > > Kelly >> > > >> > > >> > > >> > > ----- Original Message ----- >> > > From: "Yardbird" <[EMAIL PROTECTED]> >> > > To: "PC-Audio" <Pc-audio@pc-audio.org> >> > > Sent: Saturday, May 07, 2005 12:39 AM >> > > Subject: Understanding and comparing compression formats >> > > >> > > >> > > > I've just been learning how to rip music from CDs to my hard
drive
>> using >> > > > several different programs, and the one that interests me most >> > > > at >> > present >> > > > is >> > > > Windows Media Player because of the variety of formats it >> > > > offers. >> > > > >> > > > As I explore and test these formats, one thing confuses me: You >> > > > can >> rip >> > > > Windows Media Audio files about six different ways, not counting >> > > > the >> > > > lossless option. Now, I'm aware that .mp3 ripping can be
adjusted
> to
>> > use
>> > > > bit rates higher than the default 128 in order to restore a
little
> of
>> > the
>> > > > information that a lower bit rate strips out.
>> > > >
>> > > > but understanding that is simple compared to the range of .wma
>> options.
>> > > > Here's the main thing that puzzles me.  In the WMP menu for
setting
>> your
>> > > > rip
>> > > > options, there are *two* sets of .wma options, each with its own
> range
>> > of
>> > > > sound quality level.
>> > > >
>> > > > First is the .wma choice that uses a slider to provide you
with,as
>> > > > I
>> > > > recall,
>> > > > three levels of sound quality.  I've ripped the same track with
all
>> > three,
>> > > > and not only listened to them-- the differences are audible to
me,
>> > > > although
>> > > > pretty subtle compared to the difference between any of them and
a
>> less
>> > > > compressed lossless or uncompress .wav version.  Still, for
saving
>> > space, >> > > > I >> > > > appreciate the compression, so I remain interested. >> > > > >> > > > Okay. So the smallest .wma sound quality level creates a really > small >> > > > file, >> > > > much smaller than the same tune ripped to .mp3. And it doesn't > sound >> > any >> > > > worse than the .mp3, was my impression. The next higher levels > create >> > > > larger files, with the highest quality level creating a file for >> > > > any >> > given >> > > > track that's about the same size as a 192 bit rate .mp3. If I >> > > > go > this >> > > > way, >> > > > I'd suppose that's the method I'd use, so you get a little >> > > > better >> sound >> > > > quality than an .mp3 for the same file size. >> > > > >> > > > But then, right beneath this on that menu, there's a variable >> > > > bit > rate >> > > > .wma >> > > > option, again set by a slider, but this time starting at 0 per
cent
>> and
>> > > > going up.  Zero per cent of what?  And, more to the point, if
this
> has >> > to >> > > > do >> > > > with changing bit rates (doesn't the other method, I wonder? >> > > > How > else >> > > > would >> > > > you change quality except by varying the bit rate?) where are >> > > > the >> > > > indications for *what* bit rate this slider takes you through? >> > > > >> > > > So that's it. I'm really wondering about this stuff as I try to >> settle >> > on >> > > > a >> > > > preferred rip method to set for my usual use. Does anyone > understand >> > > > whatever it is I'm not getting about these two adjustable .ma > formats? >> > Is >> > > > there anywhere to read a simple primer about them? I don't feel >> > > > the >> > need >> > > > to >> > > > do research if someone can just explain what it is I'm not >> > understanding. >> > > > But just in case there's some online information about this that > would >> > > > clarify it all, that would be fine, too. >> > > > >> > > > Thanks, >> > > > Daniel >> > > > >> > > > >> > > > >> > > > -- >> > > > No virus found in this outgoing message. >> > > > Checked by AVG Anti-Virus. >> > > > Version: 7.0.308 / Virus Database: 266.11.5 - Release Date: >> > > > 5/4/2005 >> > > > >> > > > >> > > > _______________________________________________ >> > > > PC-Audio List Help, Guidelines, Archives and more... >> > > > http://www.pc-audio.org >> > > > >> > > > To unsubscribe from this list, send a blank email to: >> > > > [EMAIL PROTECTED] >> > > > >> > > >> > > >> > > >> > > _______________________________________________ >> > > PC-Audio List Help, Guidelines, Archives and more... >> > > http://www.pc-audio.org >> > > >> > > To unsubscribe from this list, send a blank email to: >> > > [EMAIL PROTECTED] >> > > >> > > >> > > >> > > -- >> > > No virus found in this incoming message. >> > > Checked by AVG Anti-Virus. >> > > Version: 7.0.308 / Virus Database: 266.11.6 - Release Date:
5/6/2005
>> > > >> > > >> > > >> > > >> > > -- >> > > No virus found in this outgoing message. >> > > Checked by AVG Anti-Virus. >> > > Version: 7.0.308 / Virus Database: 266.11.6 - Release Date:
5/6/2005
>> > > >> > > >> > > _______________________________________________ >> > > PC-Audio List Help, Guidelines, Archives and more... >> > > http://www.pc-audio.org >> > > >> > > To unsubscribe from this list, send a blank email to: >> > > [EMAIL PROTECTED] >> > >> > >> > _______________________________________________ >> > PC-Audio List Help, Guidelines, Archives and more... >> > http://www.pc-audio.org >> > >> > To unsubscribe from this list, send a blank email to: >> > [EMAIL PROTECTED] >> > >> > >> > >> > -- >> > No virus found in this incoming message. >> > Checked by AVG Anti-Virus. >> > Version: 7.0.308 / Virus Database: 266.11.6 - Release Date: 5/6/2005 >> > >> > >> > >> > -- >> > No virus found in this outgoing message. >> > Checked by AVG Anti-Virus. >> > Version: 7.0.308 / Virus Database: 266.11.6 - Release Date: 5/6/2005 >> > >> > >> > _______________________________________________ >> > PC-Audio List Help, Guidelines, Archives and more... >> > http://www.pc-audio.org >> > >> > To unsubscribe from this list, send a blank email to: >> > [EMAIL PROTECTED] >> >> >> _______________________________________________ >> PC-Audio List Help, Guidelines, Archives and more... >> http://www.pc-audio.org >> >> To unsubscribe from this list, send a blank email to: >> [EMAIL PROTECTED] >> >> >> >> -- >> No virus found in this incoming message. >> Checked by AVG Anti-Virus. >> Version: 7.0.308 / Virus Database: 266.11.6 - Release Date: 5/6/2005 >> >> >> >> -- >> No virus found in this outgoing message. >> Checked by AVG Anti-Virus. >> Version: 7.0.308 / Virus Database: 266.11.6 - Release Date: 5/6/2005 >> >> >> _______________________________________________ >> PC-Audio List Help, Guidelines, Archives and more... >> http://www.pc-audio.org >> >> To unsubscribe from this list, send a blank email to: >> [EMAIL PROTECTED] > > > _______________________________________________ > PC-Audio List Help, Guidelines, Archives and more... > http://www.pc-audio.org > > To unsubscribe from this list, send a blank email to: > [EMAIL PROTECTED] > > > > -- > No virus found in this incoming message. > Checked by AVG Anti-Virus. > Version: 7.0.308 / Virus Database: 266.11.8 - Release Date: 5/10/2005 > > > > > -- > No virus found in this outgoing message. > Checked by AVG Anti-Virus. > Version: 7.0.308 / Virus Database: 266.11.8 - Release Date: 5/10/2005 > > > _______________________________________________ > PC-Audio List Help, Guidelines, Archives and more... > http://www.pc-audio.org > > To unsubscribe from this list, send a blank email to: > [EMAIL PROTECTED] >
_______________________________________________
PC-Audio List Help, Guidelines, Archives and more...
http://www.pc-audio.org
To unsubscribe from this list, send a blank email to:
[EMAIL PROTECTED]
--
No virus found in this incoming message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.11.8 - Release Date: 5/10/2005
--
No virus found in this outgoing message.
Checked by AVG Anti-Virus.
Version: 7.0.308 / Virus Database: 266.11.8 - Release Date: 5/10/2005
_______________________________________________
PC-Audio List Help, Guidelines, Archives and more...
http://www.pc-audio.org
To unsubscribe from this list, send a blank email to:
[EMAIL PROTECTED]
_______________________________________________
PC-Audio List Help, Guidelines, Archives and more...
http://www.pc-audio.org
To unsubscribe from this list, send a blank email to:
[EMAIL PROTECTED]

_______________________________________________ PC-Audio List Help, Guidelines, Archives and more... http://www.pc-audio.org

To unsubscribe from this list, send a blank email to: [EMAIL PROTECTED]

Re: Understanding and comparing compression formats

Reply via email to