For those interested in dual mode transportation, I'll recommend University of Washington's Dualmode Debate Page. The page mentions all the projects and has a lot of papers describing the systems and discussing the benefits and problems with them.
Also MIT Alumni brought an article proposing the US should invest $1000 billion in dual mode over the next 10 years. According to the author the investment would pay back in only 2 years! What are we waiting for?
I don't think I'm clueless (but how would one know;-). I don't know a lot about encoder internals but I do have ears. The purpose of vbr is to save bits where the vbr algorithm sees fit. But what if the vbr algorithm is not up to the job? I would expect vbr with no frames <192kbps to sound superior to cbr 192kbps. But in order to encode some frames with >192kbps it needs to encode some with lower rate (for the same average bitrate). As I stated in my original post, I could hear the noise floor being modulated on some music with large amplitude low pass filtered bass (excellent candidates for low bitrate encoding). I contributed this effect to the vbr algorithm changing bitrate dynamically, and decided to use cbr 192kbps instead which I'm satisfied with (lame is a great encoder btw). Just wanted to report my experience because everybody seems so keen on vbr and after that experience - I'm not.
Thanks for the links (damn, now I need to use the rest of the afternoon on comparing and reading about encoders - again;-)
LAME developers themselfves discourage the use of CBR and I doubt you have done any ABX tests to back up your claim that 192kbps CBR sounds better than one of the VBR presets?!
Well, I compared the original wav and the two mp3s... (using xmms) but it wasn't a blind test (I was aware of which one was playing).
As I stated in my original post it has to do with the noise floor changing - (and this applies to faint echoes and reflections as well when they're almost buried in the noise). IMHO the benefit from having some frames encoded at >192kbps is not balancing out the disaster of having some frames encoded <192kbps. Or you could say that to me overall quality is more important than occasionally saving a few bits.
Recently I decided to use lame with cbr 192kbps after comparing to the preset vbr settings (including extreme). I use the settings: --cbr -b 192 -h -q0
Using vbr I can hear the noise floor being modulated e.g. by a large amplitude low pass filtered bass sound. I contribute this to vbr changing bitrate. Maybe the psychoacoustic model just doesn't fit my ears:-)
The vbr files average around 200kbps anyway, so they're not smaller than 192kbps cbr.
It would have been nice if the test included cbr as well.
I use good headphones: Sennheiser HD-25, and my mp3 player: archos jukebox recorder running the open source firmware Rockbox
You don't need to buy it. I just downloaded the pdf and read the intro. This is really well written, and he even recognizes Donald knuth in the second paragraph:
"One of the greatest programmers, Donald Knuth, describes programming not as telling a computer how to do something, but telling a person how they would instruct a computer to do something. The point is that programs are meant to be read by people, not just computers. Your programs will be modified and updated by others long after you move on to other projects. Thus, programming is not as much about communicating to a computer as it is communicating to those who come after you. A programmer is a problem-solver, a poet, and an instructor all at once. Your goal is to solve the problem at hand, doing so with balance and taste, and teach your solution to future programmers. I hope that this book can teach at least some of the poetry and magic that makes computing exciting."
How about a dedicated laptop linux distribution? So you don't have to choose all the individual drivers for the various hardware of you notebook. Instead you would just choose the manufacturer and model e.g. "Acer Travelmate 340T" and everything would be set.
> One aspect of a standing wave is that it has no effect at the speaker.
Simply not true. The radiation impedance will change and this will affect the power radiated from the speaker.
If you place another woofer next to the original one, the output will be more than double (I'm talking low frequencies here). This is because the radiation impedance changes.
It took a while for me to accept this (I'm also sceptical), but in this case, 1+1 is more than 2. As you keep piling up more loudspeakers, this effect vanishes.
Think of the standing wave as a wave coming from another woofer changing the radiation impedance and you'll see what I mean.
Did you know that the very first Ariane 5 Rocket did a selfdestruction...
No I didn't know that. Maybe that is because it is not true! AFAIK it had something to do with a buffer overflow. BTW no sane engineer would use anything else but the metric system.
I would also like to have brackets for the array indices, and have even considered writing my own preprocessor to allow that and some other syntactic sugar.
I considered that as well. I saw somebody else in this thread write that he always used different names for arrays and functions, so that wouldn't be a problem. I'm lazy. And doing something in Ada requires about 3 times as much writing as in C. It is probably just because the standard Ada library is too basic.
Saying what you mean is a very demanding requirement, and those of us who haven't been through a software engineering program don't take to the requirement too kindly.
I have been through some courses, but only learned to program by looking at and writing lots of code (some of the code I looked at was very very bad).
The Ada code I was working with was about the worst thing I have ever seen. A word for it is: typeghetti, i.e. too many type declarations which is redundant, and all dependant on eachother. No modularity whatsoever.
We'd rather slop together whatever our language of choice allows us to get away with, and pay the price for it later if we're so unfortunate to still be around when the bug reports start coming in.
When I write something short, it contains fewer bugs. IMHO one of the important things when learning to program is to learn to use the right subset of a language. Not every construct is worth using. I *always* use for-loops with index counting from 0 while it is less than the max-value (usually a #define'd constant).
IMHO some engineers are not able to distinguish "advanced" from "complicated".
I have worked in an ADA shop for 4 months. I started out by being very positive towards ADA - being told that "in ADA you write a little more than in C, but basically you just write what you mean".
Then why is an array written in the same way as a function call? Without [] I have to write:
i(j) -- i is the function which returns bla
x(j) -- x is a table lookup which is used for bla
I don't get it.
An ADA compiler writer told me that also made it much harder to make the ADA compiler.
I am a happy owner of an Acer TravelMate 340T with a Trident chipset in it. The first thing after bringing the laptop home was to install Linux Mandrake 8.0. I even tried running the initial part of the Mandrake installation program in the shop to see if the hardware in the notebook was supported by linux, before deciding on bying the laptop!
I am very sad to hear that you have decided not to support open source drivers for your upcoming chipsets and I am sure it will affect your sales negatively in the long run.
Somebody at our school tried to get the so-called "sysop" to fix a problem with the web-server: cgi-scripts were run as root and everybody could put cgi-scripts up on their personal webpages!
The sysop didn't even respond to the third email containing detailed explanation on what to change in which files to correct the problem...
To my knowledge the system was never fixed. We talked about making a web-page with one button: "don't push this!" causing a rm -Rf as root...
and then mail the URL to the head of department!
I wonder how many systems out there are as badly configured as this example?
Slashdot Mirror
For those interested in dual mode transportation, I'll recommend University of Washington's Dualmode Debate Page. The page mentions all the projects and has a lot of papers describing the systems and discussing the benefits and problems with them.
Also MIT Alumni brought an article proposing the US should invest $1000 billion in dual mode over the next 10 years. According to the author the investment would pay back in only 2 years! What are we waiting for?
DOH, I shouldn't reply to trolls. ;-)
:-)
:-(
I wasn't intending to troll - you just cited me out of context and so did I.
Happy now?
original post is now moderated flamebait and you call me a troll and clueless
I did have a track which produced artifacts (at the noisefloor) using lame with vbr. Using cbr solved the problem.
If I could find the original track I could post some evidence. But maybe lame vbr improved in the meantime and thus wouldn't show this problem now.
No, the purpose of VBR is to maintain a constant quality level
;-)
So the sound quality of cbr320 varies too much and that's why vbr was invented? Always thought it was to save bits...
I don't think I'm clueless (but how would one know;-). I don't know a lot about encoder internals but I do have ears. The purpose of vbr is to save bits where the vbr algorithm sees fit. But what if the vbr algorithm is not up to the job? I would expect vbr with no frames <192kbps to sound superior to cbr 192kbps. But in order to encode some frames with >192kbps it needs to encode some with lower rate (for the same average bitrate). As I stated in my original post, I could hear the noise floor being modulated on some music with large amplitude low pass filtered bass (excellent candidates for low bitrate encoding). I contributed this effect to the vbr algorithm changing bitrate dynamically, and decided to use cbr 192kbps instead which I'm satisfied with (lame is a great encoder btw). Just wanted to report my experience because everybody seems so keen on vbr and after that experience - I'm not.
Thanks for the links (damn, now I need to use the rest of the afternoon on comparing and reading about encoders - again;-)
Before you don't provide ABX results your findings are pretty worthless<snip>
:-)
:-)
My findings are quite valuable - because I like my mp3s better now
Just encode your stuff as you find best. I'll do the same. Everybody's happy
LAME developers themselfves discourage the use of CBR and I doubt you have done any ABX tests to back up your claim that 192kbps CBR sounds better than one of the VBR presets?!
Well, I compared the original wav and the two mp3s... (using xmms) but it wasn't a blind test (I was aware of which one was playing).
As I stated in my original post it has to do with the noise floor changing - (and this applies to faint echoes and reflections as well when they're almost buried in the noise). IMHO the benefit from having some frames encoded at >192kbps is not balancing out the disaster of having some frames encoded <192kbps. Or you could say that to me overall quality is more important than occasionally saving a few bits.
Recently I decided to use lame with cbr 192kbps after comparing to the preset vbr settings (including extreme). I use the settings: --cbr -b 192 -h -q0
Using vbr I can hear the noise floor being modulated e.g. by a large amplitude low pass filtered bass sound. I contribute this to vbr changing bitrate. Maybe the psychoacoustic model just doesn't fit my ears:-)
The vbr files average around 200kbps anyway, so they're not smaller than 192kbps cbr.
It would have been nice if the test included cbr as well.
I use good headphones: Sennheiser HD-25, and my mp3 player: archos jukebox recorder running the open source firmware Rockbox
You don't need to buy it. I just downloaded the pdf and read the intro. This is really well written, and he even recognizes Donald knuth in the second paragraph:
"One of the greatest programmers, Donald Knuth, describes programming not as telling a computer how to do something, but telling a person how they would instruct a computer to do something. The point is that programs are meant to be read by people, not just computers. Your programs will be modified and updated by others long after you move on to other projects. Thus, programming is not as much about communicating to a computer as it is communicating to those who come after you. A programmer is a problem-solver, a poet, and an instructor all at once. Your goal is to solve the problem at hand, doing so with balance and taste, and teach your solution to future programmers. I hope that this book can teach at least some of the poetry and magic that makes computing exciting."
I look forward to reading the rest!
How about a dedicated laptop linux distribution? So you don't have to choose all the individual drivers for the various hardware of you notebook. Instead you would just choose the manufacturer and model e.g. "Acer Travelmate 340T" and everything would be set.
What do you think?
...but trust me - the danish goverment would make it ok somehow! :)
What live the longest? A politicians "word" or a law?
> One aspect of a standing wave is that it has no effect at the speaker.
Simply not true. The radiation impedance will change and this will affect the power radiated from the speaker.
If you place another woofer next to the original one, the output will be more than double (I'm talking low frequencies here). This is because the radiation impedance changes.
It took a while for me to accept this (I'm also sceptical), but in this case, 1+1 is more than 2. As you keep piling up more loudspeakers, this effect vanishes.
Think of the standing wave as a wave coming from another woofer changing the radiation impedance and you'll see what I mean.
No I didn't know that. Maybe that is because it is not true! AFAIK it had something to do with a buffer overflow. BTW no sane engineer would use anything else but the metric system.
I considered that as well. I saw somebody else in this thread write that he always used different names for arrays and functions, so that wouldn't be a problem. I'm lazy. And doing something in Ada requires about 3 times as much writing as in C. It is probably just because the standard Ada library is too basic.
Saying what you mean is a very demanding requirement, and those of us who haven't been through a software engineering program don't take to the requirement too kindly.
I have been through some courses, but only learned to program by looking at and writing lots of code (some of the code I looked at was very very bad).
The Ada code I was working with was about the worst thing I have ever seen. A word for it is: typeghetti, i.e. too many type declarations which is redundant, and all dependant on eachother. No modularity whatsoever.
We'd rather slop together whatever our language of choice allows us to get away with, and pay the price for it later if we're so unfortunate to still be around when the bug reports start coming in.
When I write something short, it contains fewer bugs. IMHO one of the important things when learning to program is to learn to use the right subset of a language. Not every construct is worth using. I *always* use for-loops with index counting from 0 while it is less than the max-value (usually a #define'd constant).
IMHO some engineers are not able to distinguish "advanced" from "complicated".
I have worked in an ADA shop for 4 months. I started out by being very positive towards ADA - being told that "in ADA you write a little more than in C, but basically you just write what you mean".
Then why is an array written in the same way as a function call? Without [] I have to write:
i(j) -- i is the function which returns bla
x(j) -- x is a table lookup which is used for bla
I don't get it.
An ADA compiler writer told me that also made it much harder to make the ADA compiler.
I quit the job and is now back doing C.
Dear Sir,
I am a happy owner of an Acer TravelMate 340T with a Trident chipset in it. The first thing after bringing the laptop home was to install Linux Mandrake 8.0. I even tried running the initial part of the Mandrake installation program in the shop to see if the hardware in the notebook was supported by linux, before deciding on bying the laptop!
I am very sad to hear that you have decided not to support open source drivers for your upcoming chipsets and I am sure it will affect your sales negatively in the long run.
Best regards,
Peter Favrholdt
The sysop didn't even respond to the third email containing detailed explanation on what to change in which files to correct the problem...
To my knowledge the system was never fixed. We talked about making a web-page with one button: "don't push this!" causing a rm -Rf as root...
and then mail the URL to the head of department!
I wonder how many systems out there are as badly configured as this example?