I guess I never even considered the confusing aspect of .dmgs. Regardless of the format things get downloaded in, apps go in the Applications folder, movies go in the Movies folder, etc. nothing stays on my desktop for more than a couple days (usually while I decide whether or not I'm keeping it). If I download a .dmg I mount it, drag and drop to copy the app to the applications folder, then unmount the image, copy the .dmg to the "downloads" folder I have on my external drive, then trash the copy that is on my desktop.
Disk images have indeed been around for a long time (although I believe in OS9 the extension was usually .img, but that's irrelevant), they've just become more popular of late. I seem to remember that many minor system updates were delivered as .imgs back in the day.
Disk images have some definite advantages over standard compressed archives. Someone already mentioned creating one, filling it, then burning it. It's a neat and simple process. Also, say you have a game that requires the disk to be mounted for you to be able to play it. Often, if you have a disk image of the disk, you can mount that and you don't actually need the disk. I know that's a bit shady, but there's got to e a more legal counterpart to this advantage (that is, the fact that the computer treats just as if it were another disk).
As far as advantages to distributing software as images, I guess I don't really know. But there's absolutely no question as to whether the end user will have the right software on their computer to decompress the image, because OSX does it all by itself now (and before 10.3 the program to do it was included), whereas you can't be 100% sure about all the various compression utilities.
When you stick a CD into a Mac, the raw tracks appear as AIFFs. But if AIFF is a Mac file format, does that mean the tracks appear as some other format (like WAV) if you stick the same CD into a Win box? I always thought AIFF was the universal standard for uncompressed digital music, but I've never ripped onto a PC.
I've played AIFF files on my lowly Windows 98 box before. There's a setting in QuickTime for Windows that allows it to be the default application for playing these files.
When you stick a CD into a Mac, the raw tracks appear as AIFFs. But if AIFF is a Mac file format, does that mean the tracks appear as some other format (like WAV) if you stick the same CD into a Win box? I always thought AIFF was the universal standard for uncompressed digital music, but I've never ripped onto a PC.
I thought the exact same thing. Can anyone find any info on this one? What IS the format on a normal CD? My former girl-friend insist that it is .wave thats on CD's, since she has been through a music-producer course..
Quote:
Originally posted by steve666
I have a question. I consider myself reasonably intelligent, how would someone know to take the app out of that HD image before trashing the .dmg? And how would anyone instinctively know that they had to take the image out of that icon? It seems odd to me, but what it is is what it be I guess.
At least I know what to do now thanks to you guys. I appreciate all the info.
Well.. If the user tries to delete the .dmg while its mounted, Finder gives you a warning that it is impossible. So the user have to copy the app to the harddrive first.
But still... What is the standard CD audio format?
And, that compressed AIFF format someone mentioned, can I read more about that somewhere? I would like to know the benefits of that one. Because if it gives almost CD quality at a 6:1 compression level, then it might be worth ripping CD's in this format.
It's .cda which is CD Audio. Basicly, cd's are encoded with a file format in mind, .wav is just the uncompressed version of the song on the computer. Most CD's were masted using DATs. Different file formats is just different programs.
I liked the floppy disk icon for .img's back in OS 9. That was a better analogy. You see a floppy on your hard drive, think, oh, this is temporary - I'll copy it to my hard drive for permanent use.
That crappy white icon they use now doesn't convey any of that. Of course, I don't think my 5th grade brother even knows what a floppy disk is anymore.
Exactly. And I recall when hard drives were first being introduced, and people were confused as to why they needed to copy things onto them when they had perfectly good floppies right there...
I really don't get what's so complex about disk images. They work just like ZIP files.
ZIP files:[list=1][*]Download the ZIP file[*]Double-click the ZIP file to open the archive[*]Drag the app (or other files) to your hard drive[*]Delete the ZIP file[/list=1]
DMG files:[list=1][*]Download the DMG file[*]Double-click the DMG file to open the disk's window[*]Drag the app (or other files) to your hard drive[*]Delete the DMG file[/list=1]
The only difference is that DMG doesn't require external software, and the whole thing is just... cleaner.
I admit that having the mounted disk image icon look like a hard drive may not be the best choice, but considering so many people use removable Firewire and USB hard drives, even that's not so bad.
Imagine you have one big app, it gets loaded into RAM when opened, now, there's a module which gets executed not very often, you can have that as dll which gets loaded only when called for by main application.
In general dll is loaded into memory when outside process calls for it...
Often their location is defined in .... *drum roll* .... the registry.
And since there are often called something which is impossible to a mere mortal to comprehend, errors generated when dll is missing or of incorrect version can be very interesting to the user, who of course have no clue what just happened.
I really don't get what's so complex about disk images. They work just like ZIP files.
[snip explanation]
The only difference is that DMG doesn't require external software, and the whole thing is just... cleaner.
I admit that having the mounted disk image icon look like a hard drive may not be the best choice, but considering so many people use removable Firewire and USB hard drives, even that's not so bad.
There are two things I've seen that can be confusing to new users with disk images (more specifically to those coming from Windows and used to installers):
1) In Panther, sometimes when the disk image is mounted and a new finder window appears with the contents, it shows in the simple finder window mode without sidebar/toolbar, and they don't know what to do.
2) The concept of ejecting a file can be odd, since no physical media actually leaves the computer and back into the user's hand. While the metaphor holds and makes sense once you're told it's a disk image and how it works, I can see how it would be confusing prior to that.
I must admit, I got confused today. I downloaded the icon set mentioned elsewhere, and went on with my stuff. By the time I remembered, and got to my desktop, I saw it laying there. Of course, it looked like a folder with a custom icon. So I move it into my home directory, and see it make an alias. It took me a few seconds before I realized that it was a DMG with a custom icon.
Comments
Disk images have indeed been around for a long time (although I believe in OS9 the extension was usually .img, but that's irrelevant), they've just become more popular of late. I seem to remember that many minor system updates were delivered as .imgs back in the day.
Disk images have some definite advantages over standard compressed archives. Someone already mentioned creating one, filling it, then burning it. It's a neat and simple process. Also, say you have a game that requires the disk to be mounted for you to be able to play it. Often, if you have a disk image of the disk, you can mount that and you don't actually need the disk. I know that's a bit shady, but there's got to e a more legal counterpart to this advantage (that is, the fact that the computer treats just as if it were another disk).
As far as advantages to distributing software as images, I guess I don't really know. But there's absolutely no question as to whether the end user will have the right software on their computer to decompress the image, because OSX does it all by itself now (and before 10.3 the program to do it was included), whereas you can't be 100% sure about all the various compression utilities.
Originally posted by Towel
When you stick a CD into a Mac, the raw tracks appear as AIFFs. But if AIFF is a Mac file format, does that mean the tracks appear as some other format (like WAV) if you stick the same CD into a Win box? I always thought AIFF was the universal standard for uncompressed digital music, but I've never ripped onto a PC.
I've played AIFF files on my lowly Windows 98 box before. There's a setting in QuickTime for Windows that allows it to be the default application for playing these files.
Originally posted by Towel
When you stick a CD into a Mac, the raw tracks appear as AIFFs. But if AIFF is a Mac file format, does that mean the tracks appear as some other format (like WAV) if you stick the same CD into a Win box? I always thought AIFF was the universal standard for uncompressed digital music, but I've never ripped onto a PC.
I thought the exact same thing. Can anyone find any info on this one? What IS the format on a normal CD? My former girl-friend insist that it is .wave thats on CD's, since she has been through a music-producer course..
Originally posted by steve666
I have a question. I consider myself reasonably intelligent, how would someone know to take the app out of that HD image before trashing the .dmg? And how would anyone instinctively know that they had to take the image out of that icon? It seems odd to me, but what it is is what it be I guess.
At least I know what to do now thanks to you guys. I appreciate all the info.
Well.. If the user tries to delete the .dmg while its mounted, Finder gives you a warning that it is impossible. So the user have to copy the app to the harddrive first.
But I agree, .zip/etc makes more sense.
AIFF was indeed made by Apple, and it stands for "Audio Interchange File Format" as someone already pointed out.
The site also says that WAVE is the standard equialent on the PC-side, compared to AIFF on the mac.
Source (In norwegian)
But still... What is the standard CD audio format?
And, that compressed AIFF format someone mentioned, can I read more about that somewhere?
That crappy white icon they use now doesn't convey any of that. Of course, I don't think my 5th grade brother even knows what a floppy disk is anymore.
We've come a long way. Analogies change.
that represents the TOC (table of contents) information I believe,
which tells a normal cdplayer where songs begin and and,
how much pauze there is in between songs.
The music itself I believe is raw encoded data. (16bit/44100kHz)
.aif = apple = 16bit/44100kHz
.wav = windows = 16bit/44100kHz
It's all the same...
but it's going to go up with super-audio-cds i guess.
About the dmg's:
dmg is a compressed format for the internet right? like zip,
so when u open it, it should be a lot bigger in disksize, but it isn't.
What's up with that?
There must be something special about it, but I'm not seeing it.
I didn't read the whole thread cause, I admit, am lazy today...maybe the answer is in there and someone can copypaste the important stuff?
Greetings
It's more like tar, with an optional zip compression thrown into the mix.
ZIP files:[list=1][*]Download the ZIP file[*]Double-click the ZIP file to open the archive[*]Drag the app (or other files) to your hard drive[*]Delete the ZIP file[/list=1]
DMG files:[list=1][*]Download the DMG file[*]Double-click the DMG file to open the disk's window[*]Drag the app (or other files) to your hard drive[*]Delete the DMG file[/list=1]
The only difference is that DMG doesn't require external software, and the whole thing is just... cleaner.
I admit that having the mounted disk image icon look like a hard drive may not be the best choice, but considering so many people use removable Firewire and USB hard drives, even that's not so bad.
http://members.lycos.co.uk/tjdumple/cda.gif
Behold: the dreaded .dll ?
I did a search for the extension .dll
Originally posted by Kickaha
Sad, sick, and wrong.
That can be applied to that sorry-ass dog as well.
[edit] Bah, as I hit send I pieced it together in my mind. Dynamically Linked Library, right? But why so many? What does it do again?
In general dll is loaded into memory when outside process calls for it...
Often their location is defined in .... *drum roll* .... the registry.
And since there are often called something which is impossible to a mere mortal to comprehend, errors generated when dll is missing or of incorrect version can be very interesting to the user, who of course have no clue what just happened.
edit: image added
Originally posted by TrevorD
I really don't get what's so complex about disk images. They work just like ZIP files.
[snip explanation]
The only difference is that DMG doesn't require external software, and the whole thing is just... cleaner.
I admit that having the mounted disk image icon look like a hard drive may not be the best choice, but considering so many people use removable Firewire and USB hard drives, even that's not so bad.
There are two things I've seen that can be confusing to new users with disk images (more specifically to those coming from Windows and used to installers):
1) In Panther, sometimes when the disk image is mounted and a new finder window appears with the contents, it shows in the simple finder window mode without sidebar/toolbar, and they don't know what to do.
2) The concept of ejecting a file can be odd, since no physical media actually leaves the computer and back into the user's hand. While the metaphor holds and makes sense once you're told it's a disk image and how it works, I can see how it would be confusing prior to that.
That should be illegal.