Wikipedia:Reference desk/Archives/Computing/2008 January 23

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January 23

FL Studio question

OK this is probably a stupidly simple question but I can't find any answer in the FL help files or on the forums. How can I record setting changes over the length of a song, i.e. for a channel or group of channels outside the limits of one single pattern? For example how would I record a gradual increase in volume across a whole track? I must be doing something wrong... "record" only works for me until the end of the pattern, and then it stops. 210.138.109.72 (talk) 05:39, 23 January 2008 (UTC)

Are you looking for Automation? [1] --wj32 ^t/c 08:39, 23 January 2008 (UTC)

No, automation only applies to patterns right? But thanks for the link; I followed it through and found what I was looking for: automation clips. Funny thing though my FL studio doesn't have a drop down button when I right click the record button... hmm... Thanks! 210.138.109.72 (talk) 23:47, 23 January 2008 (UTC)

Weird Webpage

I keep seeing pages like this everywhere. What are they? Do they have a specific name?

64.163.222.115 (talk) 05:55, 23 January 2008 (UTC)

That's a Webserver directory index generated by the Apache web server. The requested object (/img/) is a directory, and it doesn't contain any specially-named files like index.html which would override the default action of listing the files. There is no official standard behind the format, and I don't know of any brief name for it. If you call it the "apache default directory listing format", people will know what you mean. --tcsetattr (talk / contribs) 06:58, 23 January 2008 (UTC)

Specifically, they are generated by mod_autoindex of the Apache web server. --Spoon! (talk) 14:29, 23 January 2008 (UTC)

"Redlining"

I had thought that the word processing facility of allowing tentative additions and deletions, to be approved or rejected later -- typically, additions and deletions by one person, for approval or rejection by another person -- was called redlining. (Maybe I picked up the terminology from XyWrite.) However, en:WP's article redlining is about something entirely different, and a hatnote there points to something else that's similarly irrelevant. What's the normal English name for this facility?

"Look it up in your word processor's menu, you lazy slob!"

But mine's in Japanese..... Hoary (talk) 09:22, 23 January 2008 (UTC)

Redline (disambiguation) gives the additional -

The practice of editing a technical drawing (since edits were traditionally done in red color) or a document compared by a computer software programme (particularly legal documents) where deleted content is often indicated by red underlined text.

for more on that particular usage see wiktionary:redline. 86.21.74.40 (talk) 10:40, 23 January 2008 (UTC)

Ah, good, so I didn't imagine it. Thank you. Does it have another name though? -- Hoary (talk) 11:03, 23 January 2008 (UTC)

Track Changes? [2] —Preceding unsigned comment added by 82.29.112.197 (talk) 21:11, 23 January 2008 (UTC)

I used "Track changes" just a few days ago for a Physics Lab report. Yes, from what you said, it appears to be track changes. Kushal^t 13:21, 24 January 2008 (UTC)

Micro SDHC card

Today I received my SanDisk Micro SDHC card. However, the card has got stuck in the device I have placed it in. How can I safely remove the card? It's very frustrating 0_o. Seraphim ^Whipp 12:20, 23 January 2008 (UTC)

What is the device? Have you tried pressing down on it? My MicroSD card reader won't relese the card when pulled, even though there is space to pull it, but if I press it down and it comes out. I presume it is sprung or something. If not then I guess start looking for screws or phone the person that made the device. TheGreatZorko (talk) 13:04, 23 January 2008 (UTC)

The device is a Cyclods evolution and unfortunately it does not have a sprung ejector :(. I have now released the card but I am worried about doing it in the future; I don't want to damage the card and render it useless. Seraphim ^Whipp 13:37, 23 January 2008 (UTC)

Contrary to how they look MicroSD cards are actually incredably sturdy, (Mine has been through the was once and has been trodden on as well) so I wouldn't be to woried. If anything I'd be worried about your CycloDS. If it is anything like my R4DS it will have a small screw on in the center, so if the card gets really stuck you can just unscrew it and take the card out that way. Just be careful about not losing the screw! They really are tiny (As an aside aren't MicroSD cards amazing. I remember my first 1GB hard drive was the size of a VCR! Now you can get 4GB storage the size of your thumbnail)TheGreatZorko (talk) 14:04, 23 January 2008 (UTC)

Thanks for the advice. I used blunt tweezers to get it out...I'm just panicking about scratching it. Boy I hope it gets easier the more you use it!

As for your last point, I thought exactly the same the day my first 4GB SDHC card arrived...then I looked at my 4GB (old version) iPod mini and the comparison was horrible... Seraphim ^Whipp 14:22, 23 January 2008 (UTC)

Dual-head + onboard video

I have been trying to find examples of setting up a computer so it can use dual-head AGP or PCIE card along with onboard video for a total of three displays. Is this possible? I know that the BIOS normally asks for the video device to initialize first, but that doesn't necessarily shut down the other video devices. So, I expect that I should be able to set up my xorg.conf file to access both the card and onboard video devices. I just can't find any examples of it being done. -- kainaw™ 14:35, 23 January 2008 (UTC)

I guess I just online better than you. Bottom line: depends on the mobo, and bios. --f f r o t h 18:39, 23 January 2008 (UTC)

You need an OS/software that actually supports multiple displays. You are limited to 1 AGP device only so if your on-board video is tied to the AGP port, you must use PCIe for your secondary displays. NYCDA (talk) 18:36, 23 January 2008 (UTC)

X does support multiple displays.. I even got it working in xfce, which has the best multi-monitor support. Problem is, you can't move monitors between windows, so you have to spawn redundant panels on the other monitor to actually start your windows over there. Dealbreaker for me was that since I have a laptop that I dock to my monitor when back at my room, I only need those panels sometimes- and when the other monitor's not connected they appear over my primary display's panels and look terrible. Oh and I think there's some program that will let you move windows between displays in X but there was some major turn-off.. I don't remember, but I was really disgusted and refused to install it. what was it.. --f f r o t h 18:43, 23 January 2008 (UTC)

Oh yeah Xinerama:

This is a particular difficulty for laptop and tablet PC users (or any mobile computer), where you commonly want to sit at a desk and use an external physical display in addition to the computer's built-in screen, but only when at the desk.

--f f r o t h 18:44, 23 January 2008 (UTC)

It appears that my motherboard doesn't have the "always on" for the on-board video. So, adding an AGP card automatically turns it off. I guess I need to go through my garbage pile and find an old PCI video card. -- kainaw™ 19:51, 23 January 2008 (UTC)

Adobe (photoshop)

hello,

basically; 1. i downloaded the 30day free trial of adobe thingy.........it has now expired

2. how do i uninstall/get rid of it???? i cant find any un install button.........and when i go to the folder in the c drive and manually delete it it says that: acroIEHelper.dll is running and therefor i cant delete the folder.........how do i solve my problem????///

thanks, --62.136.110.246 (talk) 17:56, 23 January 2008 (UTC)

Bad idea to just delete the folder. Windows keeps track of installed programs in "Add/Remove Programs" (XP) / "Programs and Features" (Vista). Open the control panel and select one of these, then find the adobe thingy and select uninstall. The uninstall application takes care of unregistering DLLs and deleting files and registry keys. I imagine you come from a mac background since you deleted the program folder.. in OS X I guess it runs some automatic (un)install script when you copy/delete things from the programs folder, which is a terrible idea and just adds unnecessary functionality to the filesystem (special folders are so windows ME), when it should be handled by an external, non-live tool. Windows does it this way.. you can manually unregister things if you want but it's complex and different for each application (much better to have an install script do it for you, like those included in deb/rpm packages) --f f r o t h 18:31, 23 January 2008 (UTC)

Um, there's no automatic install/uninstall scripting in OS X or any special folders (at least that I have ever noticed). Programs that install things in the Library folder usually have their own uninstall programs, or things simply keep everything in the Applications folder. (And most of what's kept in the Library is pretty innocuous anyway—usually just XML files that hold config information—so if they get left behind it's not a big problem). It's actually pretty convenient when programs stay modular and don't deposit themselves all over the hard drive and intertwine themselves with the system, as is routine in Windows. --24.147.69.31 (talk) 22:41, 23 January 2008 (UTC)

I thought you just have to drag an application in finder to the trash to uninstall it. --antilived^{T | C | G} 23:06, 23 January 2008 (UTC)

I've read positive reviews about a utility called Revo Uninstaller, although I haven't used it myself. Check it out and see if it can help with your problem. --72.78.108.67 (talk) 03:32, 24 January 2008 (UTC)

This may be ridiculous but please try the "add/remove program" (I gather vista uses a different name but it may just be me, Vista does not like me) in Control Panel. Does the Adobe program show up there?

By the way, some programs in Windows are too poorly designed and do not come with uninstallers. In those cases, it is best to just delete the folder in Program Files and forget about anything else. I am prettysure that Adobe programs are not like that.

Second option, under start menu go to the location where you launch your Adobe application. Do you see an Uninstall/Unwise shortcut? If the "add/remove program" does not find your software, then this could be your next best bet.

However, as you mentioned "adobe thingy", I would caution you to make sure what you uninstall. You might want to uninstall CS3 and end up uninstalling Shoclwave player! :) Kushal^t 13:17, 24 January 2008 (UTC)

Object Oriented Programming

I'm confused about what the advantages of OO programming are. I'm looking for proposals for the smallest program (in terms of, say, lines of pseudocode) for which the advantages of being able to define classes are obvious. Any ideas? Thanks. --82.29.112.197 (talk) 20:49, 23 January 2008 (UTC)

OOP is slow and horridly inefficient and made to fit upper-management-goals of "modeling real world scenarios" etc etc. But it's very good for making maintainable, easy-to-understand code that can be incorporated into a larger project. --f f r o t h 21:37, 23 January 2008 (UTC)

Okay, so there's no single program to demonstrate the advantages since the advantages only bear fruit when you want to extend, redevelop, incorporate etc? -82.29.112.197 (talk) 22:00, 23 January 2008 (UTC)

I think one is unlikely to see a small object-oriented program that can't be made smaller by an imperative or perhaps even functional programming language, which from what I have encountered is by far the most succinct way of expressing a program. For larger programs, object-oriented programs are a lot easier to work around. x42bn6 Talk Mess 22:09, 23 January 2008 (UTC)

As a programmer OO makes modularity quite easy. It's a lot easier to have one FileSystemObject that handles all filesystem functions than it is to have half a dozen functions that are used for opening file streams, in my opinion. Note that I am expressing this in social terms—benefit for the programmer—rather than computational terms; I don't know about the latter. But I would argue that the benefit to the programmer is almost always the really crucial performance issue these days—processor speed has gotten to the point where processing time for most things is rarely a major issue, whereas the development time (including how difficult it is for others to read/use the code) is always a major issue. --24.147.69.31 (talk) 22:46, 23 January 2008 (UTC)

Here's an example of OO success: the Unix file I/O API has been able to remain largely the same for the last 30+ years because of its OO design. You create an object:

 int fd = open("/some/file", ...);

use it:

write(fd, some_data, ...);

and destroy it:

close(fd);

In that 30 years, new kinds of things have come along to create/use/destroy, such as frame grabbers, DVDs, web cams, etc., but the interface has remained the same. You could probably take the original cat program, and use it on devices like this:

cat < /dev/my_ipod > /dev/my_blackberry

, devices which wouldn't exist for decades when that program was written. That kind of polymorphism is the essence of OO, and the reason that designs with calls like EngraveWaxCylinderDevice() always end up in the dustbin of software history. There are lots of languages with nice support for various OO idioms, but it's the deeper ideas of information hiding, polymorphism, and (to a much lesser degree) inheritance that make it useful for building software that will last. --Sean 00:02, 24 January 2008 (UTC)

One advantage of OO is scope. Regardless of program size, scope of variable names is important. With OO, you can have two objects with identical variable and function names and there will be no issues about redeclaring variables or functions. When code gets large, it comes in real handy. You don't need to ensure you are using a unique variable or function name. Only your class has to have a unique name.

Another advantage is in multi-programmer development. When I write the main program, I use dummy classes that have all the functions I need and provide dummy responses. This lets me get to work on the main program. Other programmers write the classes I'll really use in the end, replacing my dummy classes with the real classes. Since I don't care how the class implements what it does, I only care that the functions respond properly. It makes separation of programmer responsibility easy to handle. -- kainaw™ 01:44, 24 January 2008 (UTC)

Okay. But many of the above features (eg scope, information hiding) are part of say, C, which no-one claims is OO and in which you cannot define a class. So maybe OO is not really about objects and classes themselves but refers to the style of programming which the /ability/ to work with objects and classes encourages? And this style of programming exists outside of what we see as the proper OO languages like Java. But we wouldn't call a language itself OO unless it allowed you to define classes and this was the best way of programming in the language. Does that make sense? I'm just trying to understand what OO is. —Preceding unsigned comment added by 82.29.112.197 (talk) 08:11, 24 January 2008 (UTC)

You're on the right track there. When people figured out that writing in an OO style had some good qualities they started creating languages to make it safer and more convenient. Saying a language is OO really means "supportive of programming in an OO style", rather than "possible to write OO code in", since probably any language with (some equivalent of) function pointers can do that. As an example here's a simple C++ program:

   struct Animal {
       virtual void make_noise() = 0;
       int bad_smells_created;
   };

   struct Cat : public Animal {
       int times_pissed_on_couch;

       Cat() {
           bad_smells_created = 3;
           times_pissed_on_couch = 10;
       }

       void make_noise() {
           puts("meow!");
       }
   };

   struct Dog : public Animal {
       int number_of_bones_buried;

       Dog() {
           bad_smells_created = 100;
           number_of_bones_buried = 20;
       }

       void make_noise() {
           puts("woof!");
       }

   };

   int main() {
       Animal *dog = new Dog();
       dog->make_noise();  // woof!
       dog->bad_smells_created++;

       Animal *cat = new Cat();
       cat->make_noise();  // meow!
       cat->bad_smells_created++;
   }

and here's the same program written in C, in the same OO style:

   struct Animal {
       void (*make_noise)(void);
       int bad_smells_created;
   };

   struct Cat {
       struct Animal base_class;
       int times_pissed_on_couch;
   };

   void Cat_make_noise() {
       puts("meow!");
   }

   struct Cat* new_Cat() {
       struct Cat *this = malloc(sizeof(struct Cat));
       this->base_class.bad_smells_created = 3;
       this->base_class.make_noise = Cat_make_noise;
       this->times_pissed_on_couch = 10;
       return this;
   }

   struct Dog {
       struct Animal base_class;
       int number_of_bones_buried;
   };

   void Dog_make_noise() {
       puts("woof!");
   }

   struct Dog* new_Dog() {
       struct Dog *this = malloc(sizeof(struct Dog));
       this->base_class.bad_smells_created = 100;
       this->base_class.make_noise = Dog_make_noise;
       this->number_of_bones_buried = 20;
       return this;
   }

   int main() {
       struct Animal *dog = new_Dog();
       dog->make_noise();  // woof!
       dog->bad_smells_created++;

       struct Animal *cat = new_Cat();
       cat->make_noise();  // meow!
       cat->bad_smells_created++;
   }

It's obviously more tedious and error-prone to do it that way, but there are many, many programs that use that approach (the Linux VFS for example). Most of the code I've written in my career has been in that style, as I have mostly worked in kernel-land where C++ is unpopular. The C++ compiler does something pretty similar under the covers. --Sean 15:21, 24 January 2008 (UTC)

I have to object to your example. By definition, bad_smells_created >= times_pissed_on_couch. Other than that, thanks for the informative explanation. jeffjon (talk) 20:05, 25 January 2008 (UTC)

HTPC

Hi, i'm looking to purchase some gear to setup a HTPC for my lounge. The tuner card i have in mind is a PVR-150. However i'm not sure if this card will be able to decode a high-def signal (at least 720p) from Freeview (New Zealand) - does anyone have any idea? The documentation doesn't seem to state - i don't know if this is common knowledge or not applicable or what. Cheers for your help Boomshanka (talk) 21:53, 23 January 2008 (UTC)

I recommend steering clear of hauppauge just because they always try to hide the specs. You can go to there site and not get a clear answer on which cards are actually digital. The card you said says it has hardware mpeg encoding (which is piontless if it was digital as the digital is already mpeg encoded). It also has a large RF box... typical of old style analog reception. So its probably not even digital, let alone high-definition digital. Personally I brought a TVICO dual digital 4, it has dual HD tuners that do 720p and 1080i (which is the highest that can be broadcast terrerstially in mpeg format). It has no RF box (totally digital with digital recieving/tuning IC's.--155.144.251.120 (talk) 01:53, 24 January 2008 (UTC)

Is there any word on the official date of DVB-T HD transmission on Freeview yet? --antilived^{T | C | G} 01:58, 24 January 2008 (UTC)

Not sure - i've heard it should be in place by July - before the start of the Olympics at least Boomshanka (talk) 07:08, 24 January 2008 (UTC)

I have a pvr150 in the US and its analog only. -- Diletante (talk) 05:05, 24 January 2008 (UTC)

iTunes on Vista

iTunes doesn't seem to work too well on Windows Vista. Is there a version that does, or is there a plugin to allow Windows Media Player to sync iPods? _{WEBURIEDOURSECRETSINTHEGARDEN}^{play it cool.} 22:24, 23 January 2008 (UTC)

Here's a site about syncing from WMP (http://www.jakeludington.com/ask_jake/20050816_sync_ipod_with_windows_media_player_10.html) ny156uk (talk) 23:05, 23 January 2008 (UTC)