Wikipedia:Reference desk/Archives/Computing/2006 November 9

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1 November 9

[edit] November 9

[edit] User-Friendly guide

Published by CyberBooks Publishing House First Edition ISBN 971-93171-0-8

Please answer as soon as possible

Programming/tech books can geto outdated quicky. First, call your favorite ordinary bookstore and ask if they have it. If not, try looking on froogle.google.com or www.ebay.com . Failing both of those, call used bookstores in your area. 48v 03:10, 9 November 2006 (UTC)

lulu.com - [1] I found this by googling the ISBN number and finding a pdf preview on this website. Mishatx 03:52, 9 November 2006 (UTC)

[edit] Reverse karaoke effect

I use Audacity and it has a karaoke effect that can remove the part of a stereo track that is panned to the center. Is there a way I can instead remove everything that is panned away from center, leaving only the lead vocal (and whatever else happens to be centered in the track)? I'd like to do this using Audacity, or some other open source Linux program (sox, etc.). Philbert^2.71828 05:08, 9 November 2006 (UTC)

After you get the center part, invert its amplitude, and mix-paste it with the original. That should cancel out the center part. --Kjoonlee 05:14, 9 November 2006 (UTC)

Some alternatives: no Linux binaries, but includes source:

--Kjoonlee 05:19, 9 November 2006 (UTC)

OK, I'll take a look at the Winamp plugin. Maybe I can port it to XMMS. Philbert^2.71828 15:32, 9 November 2006 (UTC)

I've done this a few times, never with great results, but often with 'good enough' results. I use the inverse mix paste method, but find most times, if not all, the drums and base are mixed in the center too, so it's a lot of fiddling with filters to get them out. Base is easy because it's always below voice register but the hardest is snare, hi hat and cymbals, because they contain a lot of white noise. I've used over compression pretty effectively. You always end up with something that sounds pretty terrible if you listen to it clean, but I always end up mixing the vocals I've extracted with my own music and then it's not so bad. Vespine 21:41, 9 November 2006 (UTC)

[edit] Finding the syntax and code generation algorithms for programming languages

Hello, I am wondering if anybody can help me find resources that will explicitly tell me the grammar (preferably in some sort of visual form) of any programming languages. I'd also like to know if there are any good resources that will explain to me how assembly (or machine) code is generated from a language after code has been parsed.

Thanks in advance,

Robin

There is a C grammar in Backus-Naur form in The C Programming Language, for instance, and I think the GNU Compiler Collection uses a parser generator to generate its parsers, so you can have a look at the grammar as implemented.

As far as code generation goes, you might try one of the various incarnations of the Dragon book. --Robert Merkel 12:52, 9 November 2006 (UTC)

[edit] Technology/IT

Hello, my name is sam and i was wondering 'what is a virtual reality programmer' in other words 'what do they do?' I would also like to know 'how their working conditions are?'

thanks alot for your time and i hope i can get a response.

sam

A VR programmer is a programmer for VR systems. There are many areas of programming in VR. There are the graphics people who program the environment. There are the physics programmers who program how objects in VR act. There are the core programmers who program how the environment is represented in the computer and how it is converted quickly for display. There are the drivers programmers who program how the computer talks to the input/output devices. You also have engineers who develop the devices, which often includes programming test models. I used to be a programmer/engineer at Virtual Reality South. As the project manager for many VR projects, I took part in all of the different areas (being a programmer and electronic engineer, I could actually take part and not just oversee). The working conditions are like any other field - boring. The non-working conditions were fun. We'd spend hours after work playing VR Quake against each other or playing tag in VR Carmageddon. There is a side problem there. When driving home at 2:00am after playing VR carmageddon for 8 hours, you have to keep reminding yourself that the sidewalks aren't for driving on. --Kainaw ^(talk) 15:30, 9 November 2006 (UTC)

[edit] Video cameras

I am a student in school. I am facing a big problem with attathcing a video camera to my laptop. I dont have PCI slots or anything of that sort. I have a USB cable only and I need to connect it to the Laptop. When I connect the video camera, it asks for a driver. I need to somehow download it from the net. My model is a JVC, model no.- GR-D53AS. Could anyone please tell me a site from where to download? Please! Its really urgent. Thanks.

Contact JVC, or their representative, in your country and ask them. That's what product support is for. --Robert Merkel 12:58, 9 November 2006 (UTC)

I just had a look on JVC's website. Would any of this be of use to you? --Saxsux 18:48, 15 November 2006 (UTC)

[edit] Converting cassettes into digital format

I have some old language tapes which I would like to convert to digital format so I could play them on an mp3 player or on my computer and share with my friends because it's not very convenient to play it back on a tape. I have tried Nero Soundtrax but the quality of the product doesn't seem to be that satisfactory. When I play the tapes on a cassette player, the quality is generally quite good, at least I don't hear buzzing sounds like I do on the digitalised version, so I wonder if there was anything I did wrong which didn't produce the right result or are the buzzing sounds to be expected if I convert a tape? Are there any other softwares or even hardwares available on the market which I could try? Thanks a lot! Shane Shingrila 10:03, 9 November 2006 (UTC)

You're bound to get some noise if you do analogue recording. Raise the volume as high as you can without making the input clip (i.e., don't let the volume meter go red when you do the recording), use a high bit-depth (16- or 24-bit samples should be nice), and use a high sampling rate, such as 44.1 kHz. This will give you big files, but the filesize shouldn't be a big problem if you plan to compress them. --Kjoonlee 11:47, 9 November 2006 (UTC)

Use a quality encoder, such as oggenc or lame 3.9x. --Kjoonlee 11:47, 9 November 2006 (UTC)

Yes I've been careful not to let the volume meter go red but still, there is a lot of noise even though when i listen to the tape at the same time of the recording through audio monitoring, it sounds perfectly fine. The Nero Soundtrax software offers the option of de-noising and de-rumbling, which I'm really not sure what they can do, except I know it'll decrease the noise level, but it's never been quite satisfactory and I dunno how much to de-noise or de-rumble it. And by the way, I don't quite understand what a high bit-depth or a high sampling rate is, is there anywhere I can read more about it? Cos i'm planning to make a website on the Teochew language which is definitely going to include audio files. What could I read to learn more about how to handle audio files? Thanks Shingrila 17:55, 9 November 2006 (UTC)

I'm afraid I don't have much experience with noise, so I'm stumped. It might help a little if you open your mixer (by double-clicking the speaker icon in your system tray, next to your clock) and mute everything you don't use. If you go into the mixer's options and properties, you can hide/unhide entries in your mixer. Aux and Line In should definitely be muted.

If you want to learn more about digital audio, the first two sections of Graham Mitchell's An Introduction to Compressed Audio with Ogg Vorbis should be nice. If you have questions, the people at http://hydrogenaudio.org are generally very kind and helpful.

Bit-depth and sampling rate decide how finely the sound is digitized; high bit-depth and high sampling rate means higher quality but bigger files. If you're going to upload audio samples on the web, 8 bit samples and a 16 kHz sampling rate should be enough for legibility, provided there's no noise. --Kjoonlee 02:50, 10 November 2006 (UTC)

Bit-depth should be 16 or 24 bit when you do the recording, if you plan to do editing. (Noise reduction, volume changes, etc.) You can down-convert it later on. --Kjoonlee 02:55, 10 November 2006 (UTC)

For effects, you can just try the default setting, which should be a reasonable choice. If you're unsatisfied, you can either make the de-noise filter more aggressive or more passive. --Kjoonlee 02:58, 10 November 2006 (UTC)

BTW, what did you use to connect the cassette player with the computer? I once used a "mini-stereo audio cable" for the job. --Kjoonlee 11:53, 9 November 2006 (UTC)

Well, it was a cable, but I dunno if it was a "mini-stereo audio cable" like yours. Could it be the cable which gave such bad results? Shingrila 17:55, 9 November 2006 (UTC)

Not really. I just wanted to check if you had used a microphone or a cable. --Kjoonlee 02:18, 10 November 2006 (UTC)

I don't think it's the software that would be the problem, most likely the biggest source of quality loss is in the interface between your tape deck and your computer. What are your components and how are you connecting them? The 1st thing you need to check is where you are plugging in your tape output, probably either the mic or line input on your sound card. Try using the other one. Also, try recording with your computer without actually hitting PLAY on the tape, then try recording without the tape deck even plugged in. That will give you a good indicator of where the noise is coming from. If you record without the tape deck plugged in and there is still a hum, it could be an internal hum from your PC, I've seen it many times, cheap onboard sound cards can pick up interference from everything, hard disks, fans, power supplies. If that's the case and you don't want to spend a lot of money, find a friend with better components in their PC. Vespine 02:33, 10 November 2006 (UTC)

[edit] Open Office Jumping Back to the Top

I'm a teacher in the process of producing a number of review sheets for GCSE physics, and I'm using open office to do so. The Problem that I'm having is this: most of my document is comprised of floating images and text boxes. Whenever I click off an object to deselect it, Open Office jumps back to the document forcing me to scroll back down. Is there anyway to prevent Open Office from jumping back to the top where the cursor is?

Thank you in advance for any assistance you can provide.

--CGP 15:33, 9 November 2006 (UTC)

Could you provide a link to a file in which the problem arises, so that we can try for ourselves? —Bromskloss 17:04, 9 November 2006 (UTC)

Sure. Any of the ones on this page. --CGP 18:48, 9 November 2006 (UTC)

At least for me (OOo 2.0.3 winXP) clicking off the object (on the waves one that I tried) doesn't jump back to the top. -- Finlay McWalter | Talk 19:01, 9 November 2006 (UTC)

I can't reproduce it either. First, I click on an image to select it, then click beside it (inside our outside the textarea, it doesn't matter). The marker ends up pretty much where you'd expect – close to where I clicked – and no scrolling takes place. (OOo 2.0.2 on Linux and OOo 2.0 on Windows) —Bromskloss 19:11, 9 November 2006 (UTC)

OK, good to know. It's either the version I'm using (The version from portable apps) or I just don't know how to use Open Office : ) --CGP 19:26, 9 November 2006 (UTC)

Heh, well I haven't used their programs, but I doubt the latter! —Bromskloss 20:13, 9 November 2006 (UTC)

I attempted (with the portable USB version) and could not replicate the problem. The first document I downloaded had text but not in text boxes; maybe that's why.. are you sure the version you're running is up-to-date? --Username132 (talk) 20:44, 9 November 2006 (UTC)

This sounds similar to a problem I've encountered with many programs:

1) The text cursor is flashing happily at the top of the file.

2) Instead of using the text cursor, I use the scroll bars to move down until I find what I want.

3) However, when my mouse pointer slips off the scroll bar, the program jumps back to the top, because that's where the text cursor is.

StuRat 04:19, 10 November 2006 (UTC)

I had a similar issue for a completely different reason. I had an embedded math object (a bunch of formulas). The only "text" on the page was the title. There was no text after the embedded math object. So, when I clicked outside the object, it moved the cursor to the end of the only text on the document - the title. I fixed it by adding a blank line at the end of the document. --Kainaw ^(talk) 22:45, 11 November 2006 (UTC)

[edit] Video Conversions

I have a compact home theater system Panasonic Sa-HT335 and the tft computer monitor phillips 170b.The dvd player has s-video,scart,and component video outputs. How can I connect it to my pc screen? do i need some special video converter or just a cable?????

Look for a <input> to VGA Adapter on Google, replacing the word "<input>" with the appropriate type of video output from your DVD player. You should find many links. —Mitaphane _talk 00:03, 10 November 2006 (UTC)

To answer your question, you need a special video converter. Years ago it was not likely to cost you less then about US$100, doing a very quick search it looks like things haven't changed very much..Vespine 02:11, 10 November 2006 (UTC)

[edit] Bluetooth Stacks and MAC addresses (especially dodgy ones)

My bluetooth dongle has an illegal MAC address (all ones I think) - did the dodgy people in hong kong save money by doing this (I figure you must have to pay money to some MAC adddress coordinator)? Also, someone was telling me about bluetooth stacks - there's no Wikipedia article on it, so which article would tell me about whatever it was they were trying to tell me about? --Username132 (talk) 20:31, 9 November 2006 (UTC)

To make sure that every network device in the world has a unique address, companies are assigned a unique encoding key.. which you do have to pay for --⁪froth^{T C} 02:41, 10 November 2006 (UTC)

[edit] I am looking for technical advice on connecting an old Printer to a new PC. No, really, I'm not; read the bottom paragraph - I'm thanking people for helping me earlier. READ the bottom paragraph!!

May I first apologise for reproducing the italicised passage below from an earlier entry on the miscellaneous page. Can I also apologise for the ravings of the nutcase that keeps changing my question above, I don't know what I did to upset him/her but boy, is s/he sore at me. Thanks. Regrettably, when the adapter I boasted about arrived today it didn't fix the problem I am going to have when my new PC arrives next week. My PC currently connects to my UMAX scanner vis 25 pin parallel ports, and then the scanner connects to the EPSON Stylus 600 via 36 pin parallel ports. But replacing the PC to scanner cable with the USB/parallel adapter just will not work. The printer uses a LPT1 port on the PC and the adapter supplier says it is unlikely their adapter will work with that port. I am not being a cheapskate in trying to avoid the cost of a plug and play printer/scanner for my new PC. I am just a pensioner who enjoys the web and printing photos of my grandkids and family holidays. I can buy really cheap inkjet cartridges for my current printer as its quite old, and they are not chipped. But replacement cartridges for all the new printers I have checked out are really expensive, and they are all chipped. So I wondered if one of you wizards could suggest a way of making my PC 'see' my printer via the USB/25 pin parallel adapter, or to suggest a USB printer/scanner that uses less expensive ink cartridges. Thanks in anticipation.

This is not a question - it's a big thankyou to you wonderful Wikipedians. I suspect someone will give me short shrift for NOT posing a question here; whilst it is likely that someone else will tell me this should be on the Computing Question Page - but I have chosen to say thankyou here as I think it more a miscellaneous matter. I ordered a new desktop PC today and thought I had asked all the right questions before doing so. Only afterwards did I visit the supplier's website and discover he no longer fits parallel ports, using only USBs instead. And my printer and scanner are both quite old but still working perfectly, and of course, they are fitted with the former. So the supplier invited me to invest about £150 or $300 on new kit that would be fitted with USB ports and cables. But instead, I used Wikipedia and discovered I could buy a USB - Parallel adaptor. I just ordered one online, and spent £6 or $12. You saved me a load of dosh and for that, many thanks to each. Next time I shall be more careful and ask my questions here (or on the Computing page) first. White Squirrel 22:29, 9 November 2006 (UTC)

First off, a tad long, but I thank you for your thanks. What operating system do you run? A parallel-to-USB adapter should cause the auto-detection of the printer I believe. Splintercellguy 02:53, 10 November 2006 (UTC)

Actually, sorry, but I disagree. Not about the 'a tad long' bit, i agree with that ;) but the rest i think is wrong. An old printer without USB in the 1st place won't be plug and play and will not be 'automatically' detected by your computer. Especially if you are using a lpt to usb adapter. You would need someone to code a usb driver specific to your printer, in other words, absolutely no way. Does your computer have PCI expansion ports? If so, what you need is a 'PCI - Parallel port card'! Here are some examples. Vespine 04:09, 10 November 2006 (UTC)

Sorry, but I have to disagree too :P. You definitely still need to install the necessary parallel drivers for the printer, but as my understanding goes, the OS should automatically detect the Parallel-to-USB adapter, and install one of the default USB drivers for it. Then you would Add Printer the printer if you don't already have a printer, or change the printer port to the virtual USB one. Splintercellguy 07:00, 10 November 2006 (UTC)

I think splintercellguy is probably right- a PS/2 to USB mouse adapter I have is autodetected as a USB mouse. --⁪froth^{T C} 19:14, 14 November 2006 (UTC)

Thanks Folks, I will look into your suggestions and let you know the outcome. I also had a quick word with my new PC Supplier and he suggests it might be able to see my old printer/scanner so not to give up yet. Again, I will let you know next week. Brief enough??? Thanks again.195.93.21.6 13:38, 10 November 2006 (UTC)

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