Wikipedia:Reference desk/Archives/Computing/2009 August 3

Welcome to the Wikipedia Computing Reference Desk Archives
The page you are currently viewing is an archive page. While you can leave answers for any questions shown below, please ask new questions on one of the current reference desk pages.

August 3

Use one MySQL view column to calculate another

What's the most elegant workaround to the restriction that no column in a MySQL view can refer to another column's output from the same row of the same view? NeonMerlin 01:18, 3 August 2009 (UTC)

As far as I know there is no such built in feature in MySQL. You could either have a program updating the dynamic column every so often, or implement that in the program that reads your database(when you read the db, you could just have a "virtual" column, in a variable and pretend like it came from the db) Mile92 (talk) 03:29, 3 August 2009 (UTC)

What I mean is that I have a view that contains the following two columns:

CREATE VIEW ... AS SELECT ..., least(max(copylimit.max_copies), maxdesiredcopies()) as desired_copies,
greatest(least(max(copylimit.max_copies), maxdesiredcopies()) - total_copies, 0) as lacking_copies
FROM ...

and I'd like to eliminate the redundant least(max(copylimit.max_copies), maxdesiredcopies()) if it's possible. NeonMerlin 18:21, 3 August 2009 (UTC)

Downloading ALL attached pictures of a forum?

I need help Downloading ALL attached pictures of a forum, the pictures are posted on the website under \attachments. I have tried using Extremepicturefinder and picture ripper, but both programs have trouble following the links and threads. All of the pics are posted under a single category but in different threads. The only way I've found is downthemall but thats a grueling process of going through hundreds of threads! anyone have any ideas? --Gary123 (talk) 02:57, 3 August 2009 (UTC)

You could use the UNIX tool called wget. It is made for this kind of stuff. Here's a tutorial on how to download a whole site and the files on it using wget: [1]. Just read the documentation for wget and you can eventually filter all that to output just images and just from one category. And yes, you can run wget on windows, just search it on google. Mile92 (talk) 03:32, 3 August 2009 (UTC)

I've used neodownloader for something similar and it's awesome. It's not a free program though, but *ahem* there are some cracked versions floating about the net which work a treat // 20:40, 3 August 2009 (UTC)

Resetting a LayoutManager in Java

Resolved

Hi, Java programmers! I'm writing a Swing program that has my subclasses of JComponents that resize themselves after the main frame is resized (i.e. fires ComponentEvent.COMPONENT_RESIZED). The hierarchy is JFrame >> JLayeredPane >> JPanel, and I'm using a GridBagLayout. When the event is fired, all my JComponents resize themselves correctly, but they stay in the same position in the JFrame and overlap each other (when they resize larger). The problem seems to be with the LayoutManager, which isn't laying out my JLayeredPanes to give them the new space they need. I have overridden getPreferredSize() to indicate the amount of space needed after resizing events. What else do I need to do to get the GridBagLayout to space out my JLayeredPanes? Thank you!--el Aprel (^facta-_facienda) 03:37, 3 August 2009 (UTC)

GridBagLayout disregards the preferred size of components (on most implementations, anyway). You need to specify the grid sizes using the GridBagConstraints object. Nimur (talk) 05:57, 3 August 2009 (UTC)

Thanks! I had a look at my code for creating the GridBagConstraints and fixed the problem, but now something else has cone up. When the user resizes the JFrame, the contents all resize themselves in response, but the LayoutManager doesn't re-lay them until the next resize (which can be as simple as clicking to drag the JFrame but not making it any bigger). I suspect that the LayoutManager is re-laying the contents before the resize each time. How can I make the LayoutManager not do its job until after my code resizes the contents? Thank you!--el Aprel (^facta-_facienda) 19:46, 3 August 2009 (UTC)

Oh, just found the doLayout() method in java.awt.Container and think that solved my second problem. I try to look at all my possiblilities and be really stumped before I post, but sometimes I just for get to try one more thing.... Thanks again, Nimur, for your response to this and my previous questions. I appreciate your help and support despite my Java ineptness.--el Aprel (^facta-_facienda) 20:07, 3 August 2009 (UTC)

Blogging

Hello. I have no experience in blogging, but want to start a blog. Is it possible to earn money through blogging, i.e. through advertisement in blogs? Does wordpress allow advertisement in personal blogs? How to find/contact an advertiser? And which is the best weblog hostingprovider? --GeneticRobot (talk) 08:22, 3 August 2009 (UTC)

It's possible, sure, but it's not probable. If you're really funny, or knowledgeable about your topic, or famous, or otherwise interesting, you may attract advertisers that are actually willing to pay decent money, but chances of this happening aren't too good. Merchandising is probably going to be a lot more profitable than advertising, but again, you need to have a loyal (and large) reader base for that to be an option. You should understand that first you need to make a name for yourself as someone worth reading, and then you can start think about making money -- and for that to really work, you need to do it in a way that doesn't alienate those people who're reading you. It's not an easy trick to pull off, and you should understand that the odds aren't on your side. Making a living -- or any kind of income, really -- from blogging is the exception, not the rule. Still, if you're a good writer, you have a shot.

As for your other questions, I believe the free blogs you can get at WordPress.com allow advertising, but I'm not sure. You find advertisers the way anyone finds them: you find someone you think might want to reach your audience, and you ask them if they would be interested. That, of course, can take a lot of time and effort, and you need to have a product -- that is to say, your blog -- that they think is interesting and popular enough to be worth their dime. This means you already need to have a lot of popularity before you start talking to anyone. Some people are in a position where advertisers approach them, but you really can't count on that. I couldn't tell you which provider is the best. It largely depends on what your requirements are.

I don't mean to rain on your parade here, but if you're thinking this is an easy way to get some money, you really need to reconsider. I'm not saying it's impossible, but chances are it's not going to happen, and it's certainly not going to happen without a great deal of work. -- Captain Disdain (talk) 08:45, 3 August 2009 (UTC)

(Sorry - experience and opinion alert!) - Google is purported to send you checks for ads put on your blog on Google's Blogger, but I've been blogging for years and have never once received a check, because, basically anyone who visits my blogs does so because they want to read my blog, not run around clicking on advertisements (and you have to agree to not clicking on them yourself). In my experience, it's not a good way to make cash, but you can try it. As said above, if you a good at writing about your topic, you will certainly attract a lot of readers, and companies may pay you to host their ads, but I doubt you'd get much cash (if you a good at writing about your topic, you'd be better off writing a book) - good luck, anyway, though. --KageTora - (영호 (影虎)) (talk) 11:43, 3 August 2009 (UTC)

There are a LOT of articles online about how hard it is to make money while blogging. Some people pull it off spectacularly well (and get book deals, etc.) but they are actually quite rare. If you want to blog, definitely give it a shot! But I wouldn't quit your day job unless substantial income is coming in. As for ad revenue, most people use Google Ads at least in the beginning, because anyone can sign up for those easily. --98.217.14.211 (talk) 14:36, 3 August 2009 (UTC)

What do the clock and viruses have in common?

I work in a school in Korea and recently there was an announcement that government institutions were hit by a virus (three times), and we were advised that the best way to combat the virus was to reset the time on the clocks on all the computers to an earlier time. We did this, and luckily none of our computers were affected, but I am wondering why this advice was issued. What does resetting the time on the clock have to do with the viruses? Oh, and it wasn't a system restore, it was a case changing the time. This confused me, and nobody could tell me the answer. --KageTora - (영호 (影虎)) (talk) 11:51, 3 August 2009 (UTC)

(My guess)I guess that the virus was set to activate after a certain time, so setting the clocks before then eg 1 year back or something.? would prevent the virus from activating. I'd assume this was a temporary measure whilst they worked out how to remove the virus. 83.100.250.79 (talk) 12:05, 3 August 2009 (UTC)

See logic bomb — Matt Eason ^{(Talk • Contribs)} 15:43, 3 August 2009 (UTC)

Formatting strings in Python

I'm programming in Python and this trying to format strings with a code taken directly from the Python tutorial found here. This is the code I tried: print 'We are the {0} who say "{1}!"'.format('knights', 'Ni') and this is the outcome:

Python 2.5.2 (r252:60911, Oct  5 2008, 19:24:49) 
[GCC 4.3.2] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> print 'We are the {0} who say "{1}!"'.format('knights', 'Ni')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'str' object has no attribute 'format'

Why doesn't it work? Is it because I'm using an old version of Python, because I tried a lot of examples from the Python tutorial and they all failed. --BiT (talk) 12:09, 3 August 2009 (UTC)

str.format is new in Python 2.6 (ref), and you're running 2.5.2. -- Finlay McWalter • Talk 12:17, 3 August 2009 (UTC)

Ah, the shame. I'm at my girlfriend's place using her computer and decided to finally start learning programming but apparently she hasn't upgraded Python to 3.1. Bad thing is that I don't have root access so there isn't much I can do about it until she gets back from work =) thank you --BiT (talk) 12:48, 3 August 2009 (UTC)

It's unlikely you need Python3, and I wouldn't recommend updating, as too many tutorials will contain code that won't work (that'll be easy to fix, but that will confuse you as a beginner). You can do that same print with print 'We are the %s who say "%s!"' % ('knights', 'Ni') -- Finlay McWalter • Talk 13:09, 3 August 2009 (UTC)

Yes I was just about to ask whether using "%" to format strings is exactly the same as using {}? Is one better than the other? Also, is it bad upgrading to the third Python version? I've heard about some changes like the print command being a function in Python 3.. but that's about all I know. Should I maybe upgrade to 2.6? --BiT (talk) 14:24, 3 August 2009 (UTC)

I'd stick with % to begin with, again because most code you'll see and most tutorials will be written that way. Incidentally, % has a nice feature where you can print named elements from a dictionary, and locals() is a dictionary containing the list of local variables. So you can print local variables like this:

      name="john"
      age=23
      # then, some time later...
      print "my name is %(name)s and I am %(age)d years old" % locals()

which can be handy when you've got a large print with many fields, and you want to move things around without having to reorder the data tuple. -- Finlay McWalter • Talk 16:31, 3 August 2009 (UTC)

I see (I compiled Python3.1 so now I can use both the old version and new). Nevertheless the official Python page does say "Since str.format() is quite new, a lot of Python code still uses the % operator. However, because this old style of formatting will eventually removed from the language str.format() should generally be used.". Shouldn't I rather use str.format() then? --BiT (talk) 15:36, 4 August 2009 (UTC)

Another problem... I tried compiling Python 3.1 and then downloaded Python 3 using apt-get but it worked on neither one! What's going on here? This is the result for Python 3.1:

 Python 3.1 (r31:73572, Aug  3 2009, 20:24:49) 
 [GCC 4.3.2] on linux2
 Type "help", "copyright", "credits" or "license" for more information.
 >>> print 'We are the {0} who say "{1}!"'.format('knights', 'Ni')
   File "<stdin>", line 1
     print 'We are the {0} who say "{1}!"'.format('knights', 'Ni')
                                         ^
 SyntaxError: invalid syntax

And this is the result for Python 3.0:

 Python 3.0rc1+ (py3k, Oct 28 2008, 09:23:29) 
 [GCC 4.3.2] on linux2
 Type "help", "copyright", "credits" or "license" for more information.
 >>> print 'We are the {0} who say "{1}!"'.format('knights', 'Ni')
   File "<stdin>", line 1
     print 'We are the {0} who say "{1}!"'.format('knights', 'Ni')
                                         ^
 SyntaxError: invalid syntax

It's the same Monty Python reference as I used first time (boy there sure are a lot of them in Python tutorials), taken directly from the official documentation- on a Python version I downloaded from the official Python webpage, and compiled from source and on another version downloaded directly from the Ubuntu repositories but it still doesn't work! What is going on?! --BiT (talk) 20:18, 4 August 2009 (UTC)

Ok, phew =) I managed to solve my own problem. By using dir(str) I saw that format was included in the list of operations for strings.. so I tried formatting my strings without the print function and it worked!

"Thank you {0} for helping me!".format('Finlay')

=)

Resolved

Audio Streaming

Is it possible to stream voice quality audio files over a LAN with a delay of less than a second? Is it possbile on a thin client system like citrix?--202.164.141.164 (talk) 12:40, 3 August 2009 (UTC)

On a good LAN, with "residential"-style traffic, you can expect network latency lower than 1 millisecond on average. However, audio acquisition, (from the microphone to the sound-card to the operating system) is always the bottleneck that I find - with latencies ranging anywhere from <1ms to 500 ms (totally unsuitable for "real-time" processing). Also, if you intend to encode, downsample, or otherwise operate on the signal, you can expect a delay equal to the computation time. Your best bet is to invest in a high quality sound-card which specifically advertises low-latency on linux. Nimur (talk) 16:19, 3 August 2009 (UTC)NOOO

"Volume Header needs minor repair"—2006 Intel MacBook 10.4.11

This is about my flash drive that seems to have some issues. Whenever I use Disk Utility to repair it, it says it repaired it successfully but it finds the error again when I "repair" the flash drive with the disk utility again. Could someone tell me what is wrong with my flash drive? Thanks. Kushal (talk) 13:23, 3 August 2009 (UTC)

Here's the log of a typical event.

Disk Utility log snippet

|headerstyle=background:#ccccff}}

**********
Aug  3 08:12:14: Disk Utility started.

Verify and Repair disk “Mac”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
Volume Header needs minor repair�
Repairing volume.
Rechecking volume.
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
The volume Mac was repaired successfully.
Mounting Disk

1 HFS volume checked
Repair attempted on 1 volume
	1 HFS volume repaired


Eject of “Generic USB Flash Drive Media” succeeded

**********
Aug  3 08:18:58: Disk Utility started.

Verify and Repair disk “Mac”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
Volume Header needs minor repair�
Repairing volume.
Rechecking volume.
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
The volume Mac was repaired successfully.
Mounting Disk

1 HFS volume checked
Repair attempted on 1 volume
	1 HFS volume repaired


Verifying volume “Mac”
The disk “Mac” could not be unmounted


Verify volume failed with error Could not unmount disk




Verify and Repair disk “Mac”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
Volume Header needs minor repair�
Repairing volume.
Rechecking volume.
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
The volume Mac was repaired successfully.
Mounting Disk

1 HFS volume checked
Repair attempted on 1 volume
	1 HFS volume repaired



**********
Aug  3 08:19:32: Disk Utility started.

Verify and Repair disk “Mac”
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
Volume Header needs minor repair�
Repairing volume.
Rechecking volume.
Checking HFS Plus volume.
Checking Extents Overflow file.
Checking Catalog file.
Checking Catalog hierarchy.
Checking volume bitmap.
Checking volume information.
The volume Mac was repaired successfully.
Mounting Disk

1 HFS volume checked
Repair attempted on 1 volume
	1 HFS volume repaired

Kushal (talk) 13:23, 3 August 2009 (UTC)

When you say it "finds the error again", do you mean if you run Disk Utility again right away, or the next time you insert the flash drive? If the first one, then it sounds like Disk Utility isn't actually fixing the error, and if the second one, it means the disk probably isn't being removed/unmounted safely. Another alternative is that the drive is starting to physically fail, but I'd only consider this option if you've had the flash drive for a year or more, or if all else fails.

If Disk Utility isn't fixing the error, you can use fsck. First, open a command prompt, either with Terminal or single-user mode. Typing "diskutil list" should show you the device name for your flash drive if it's currently mounted. Then type "fsck -f flash drive device name". If it finds errors, it'll ask if you want to repair them. It should give you more information than Disk Utility, so if it still fails, hopefully you'll have more information for us. Indeterminate (talk) 20:18, 3 August 2009 (UTC)

Thank you for your reply, Indeterminate. I did what you asked me to do and here's the result for fdisk:

fsck -f /dev/disk1

• • /dev/rdisk1 (NO WRITE)

BAD SUPER BLOCK: MAGIC NUMBER WRONG

LOOK FOR ALTERNATE SUPERBLOCKS? no

Is that giving any indication to what we need? When I said it finds errors again, I mean both. It does it if I run disk utility right away and when I eject and reinsert the drive (I usually eject drives safely). The flash drive is almost two years old but I am not sure if it is physically failing yet. Anything else that I could do to give you more information? Thanks, Kushal (talk) 22:39, 3 August 2009 (UTC)

It is quiet in here. Please help? :( Kushal (talk) 23:19, 4 August 2009 (UTC)

It looks like you've just got some corruption, and it's tricky for the automated tools to handle. Do you have an option to say "yes" to looking for alternate superblocks? If so, I'd try that. Hopefully it'll tell you that you have a backup superblock at (for example) address 32. Then you can run fsck -b 32 -f /dev/disk1, which will tell it to restore from the alternate superblock 32. If you're very lucky, it'll automatically fix it for you. Another way to try finding the backup superblocks on the drive is to enter newfs -N /dev/disk1, but you'll still need to do fsck -b to tell it to use the backup. If you don't care about the data currently on the drive (or if there aren't any backup superblocks), reformatting the drive might also fix the problem. Indeterminate (talk) 01:58, 5 August 2009 (UTC)

Actually, you might also want to see this discussion. It looks like this could be an indication of hardware failure. No guarantees, though. Indeterminate (talk) 02:03, 5 August 2009 (UTC)

Is the "this discussion" supposed to link to the same about page? Just wondering. Thanks. Kushal (talk) 14:04, 6 August 2009 (UTC)

Thanks for your reply. I found a bunch of backups with newfs but none of them seem to work. Is it possible to salvage this flash drive? I can still use it to carry data around (although it acts strangely sometimes) but my priority right now is getting a Mac installer on it so that if (or should I say when) the hard disk on my computer crashes, I can replace it with the 320 GB WD I bought recently. (No, the DVD drive just spits the disc out and I don't trust slot-loading on anything unless its a Wii anymore... long story.)

What should be the next step to take? Thanks. Kushal (talk) 13:06, 6 August 2009 (UTC)

Terminal log snippet

Last login: Thu Aug  6 07:03:53 on console
Welcome to Darwin!
Spiderman:~ kush$ diskutil list
/dev/disk0
   #:                   type name               size      identifier
   0:  GUID_partition_scheme                    *55.9 GB  disk0
   1:                    EFI                    200.0 MB  disk0s1
   2:              Apple_HFS Macintosh HD       55.6 GB   disk0s2
/dev/disk1
   #:                   type name               size      identifier
   0:  GUID_partition_scheme                    *3.9 GB   disk1
   1:                    EFI                    200.0 MB  disk1s1
   2:              Apple_HFS Boot               3.6 GB    disk1s2
Spiderman:~ kush$ fsck -f /dev/disk1
** /dev/rdisk1 (NO WRITE)
BAD SUPER BLOCK: MAGIC NUMBER WRONG

LOOK FOR ALTERNATE SUPERBLOCKS? no

Spiderman:~ kush$ fsck-b 32 -f /dev/disk1
-bash: fsck-b: command not found
Spiderman:~ kush$ fsck -b 32 -f /dev/disk1
Alternate super block location: 32
** /dev/rdisk1 (NO WRITE)
BAD SUPER BLOCK: MAGIC NUMBER WRONG
Spiderman:~ kush$ newfs -N /dev/disk1
Warning: Block size and bytes per inode restrict cylinders per group to 4.
Warning: 2688 sector(s) in last cylinder unallocated
disk1:  8189952 sectors in 1004 cylinders of 255 tracks, 32 sectors
        3999.0MB in 251 cyl groups (4 c/g, 15.94MB/g, 3968 i/g)
super-block backups (for fsck -b #) at:
 32, 32704, 65376, 98048, 130720, 163392, 196064, 228736,
 261408, 294080, 326752, 359424, 392096, 424768, 457440, 490112,
 522784, 555456, 588128, 620800, 653472, 686144, 718816, 751488,
 784160, 816832, 849504, 882176, 914848, 947520, 980192, 1012864,
 1045536, 1078208, 1110880, 1143552, 1176224, 1208896, 1241568, 1274240,
 1306912, 1339584, 1372256, 1404928, 1437600, 1470272, 1502944, 1535616,
 1568288, 1600960, 1633632, 1666304, 1698976, 1731648, 1764320, 1796992,
 1829664, 1862336, 1895008, 1927680, 1960352, 1993024, 2025696, 2058368,
 2091040, 2123712, 2156384, 2189056, 2221728, 2254400, 2287072, 2319744,
 2352416, 2385088, 2417760, 2450432, 2483104, 2515776, 2548448, 2581120,
 2613792, 2646464, 2679136, 2711808, 2744480, 2777152, 2809824, 2842496,
 2875168, 2907840, 2940512, 2973184, 3005856, 3038528, 3071200, 3103872,
 3136544, 3169216, 3201888, 3234560, 3267232, 3299904, 3332576, 3365248,
 3397920, 3430592, 3463264, 3495936, 3528608, 3561280, 3593952, 3626624,
 3659296, 3691968, 3724640, 3757312, 3789984, 3822656, 3855328, 3888000,
 3920672, 3953344, 3986016, 4018688, 4051360, 4084032, 4116704, 4149376,
 4182048, 4214720, 4247392, 4280064, 4312736, 4345408, 4378080, 4410752,
 4443424, 4476096, 4508768, 4541440, 4574112, 4606784, 4639456, 4672128,
 4704800, 4737472, 4770144, 4802816, 4835488, 4868160, 4900832, 4933504,
 4966176, 4998848, 5031520, 5064192, 5096864, 5129536, 5162208, 5194880,
 5227552, 5260224, 5292896, 5325568, 5358240, 5390912, 5423584, 5456256,
 5488928, 5521600, 5554272, 5586944, 5619616, 5652288, 5684960, 5717632,
 5750304, 5782976, 5815648, 5848320, 5880992, 5913664, 5946336, 5979008,
 6011680, 6044352, 6077024, 6109696, 6142368, 6175040, 6207712, 6240384,
 6273056, 6305728, 6338400, 6371072, 6403744, 6436416, 6469088, 6501760,
 6534432, 6567104, 6599776, 6632448, 6665120, 6697792, 6730464, 6763136,
 6795808, 6828480, 6861152, 6893824, 6926496, 6959168, 6991840, 7024512,
 7057184, 7089856, 7122528, 7155200, 7187872, 7220544, 7253216, 7285888,
 7318560, 7351232, 7383904, 7416576, 7449248, 7481920, 7514592, 7547264,
 7579936, 7612608, 7645280, 7677952, 7710624, 7743296, 7775968, 7808640,
 7841312, 7873984, 7906656, 7939328, 7972000, 8004672, 8037344, 8070016,
 8102688, 8135360, 8168032,
Spiderman:~ kush$ fsck -b 32704 -f /dev/disk1
Alternate super block location: 32704
** /dev/rdisk1 (NO WRITE)
BAD SUPER BLOCK: MAGIC NUMBER WRONG
Spiderman:~ kush$ fsck -b 65376 -f /dev/disk1
Alternate super block location: 65376
** /dev/rdisk1 (NO WRITE)
BAD SUPER BLOCK: MAGIC NUMBER WRONG
Spiderman:~ kush$ fsck -b 8135360 -f /dev/disk1
Alternate super block location: 8135360
** /dev/rdisk1 (NO WRITE)
BAD SUPER BLOCK: MAGIC NUMBER WRONG
Spiderman:~ kush$

Are the snippets from the terminal of any use? Kushal (talk) 15:34, 8 August 2009 (UTC)

Flash player is sometimes slow

Everything that runs flash such as Browser's Flash player , vlc player's flash video player etc runs (at times) slow for no apparent reason. Only cure is restarting the machine. Once it runs at normal speed, no problems until I shut down the machine. It does not matter even if I restart the browser or vlc player. I use flash player 10 on windows and the machine its self is fast enough- well over 2GHZ and hundreds of RAM. Please say how to fix flash. —Preceding unsigned comment added by 131.220.46.25 (talk) 13:28, 3 August 2009 (UTC)

What browser are you using? Also does the flash player stutter, or play like a slideshow missing frames.?83.100.250.79 (talk) 13:58, 3 August 2009 (UTC)

When it is slow, it is slow on both browsers ( IE and firefox). In both browsers, it would play like a slideshow when it is slow, after the movie is over (sound is track is finished and youtube shows play again icon) it would play the remaining video at slightly higher speed than slideshow. This lag between audio and video exists only in big ( greater than 10 minutes and better quality videos). —Preceding unsigned comment added by 131.220.46.25 (talk) 08:09, 4 August 2009 (UTC)

Have you tried using something other that vlc for flash video to see if the problem is still there?83.100.250.79 (talk) 18:10, 4 August 2009 (UTC)

Also are flash video files slow when played as outside the browser.83.100.250.79 (talk) 19:00, 4 August 2009 (UTC)

Cpmputer is freezing after 6 to 9 hours of use and dvd drive problem

Recently, I am having bitter experience with my newly upgraded hardware. If I run my system for 6 to 9 hours it gets freeze. The symptoms are: mouse pointer stops for a while then I can move it and again it stops, music gets crashed if I play. Same thing happens with keyboard. My usb modem also gets disconnected at that time. I tried to run my system with case cover open and blow a fan into inside (My pc case contains 4 cooler fan inside though). But nothing happens. It gets frozen (until I press power button to shut it off). I am using vista 64 bit ultimate. My mobo is 750i SLI Nvidia Geforce, Graphics card ATI Radeon 4890 1 GB (GPU Clock 850 MHz). All are 64 bit supported.

Another problem I have just faced is my dvd rom icon suddenly disappear from "my computer" and system gets frozen. The above mentioned symptoms were also happening. It happened when I inserted a dvd.

I checked system with diagnostics tools (prime95) and no errors. My all drivers are up to date.

Is overheating causing all these problems? Should I reduce my GPU Clock from 850MHz to 750MHz (ATI Radeon 4870 1 GB) or 625 MHz (ATI Radeon 4850 1 GB)?--119.30.36.54 (talk) 17:32, 3 August 2009 (UTC)

Download and run PC Wizard, which has a temperature sensor button. Here are my temperatures: CPU=35C, mainboard=21C, GPU=47C, Hard Disk=30C. Also check that all your voltages are correct. If the figures you get are close to these, then you do NOT have a heating problem. If your GPU is for example 70C, then it IS overheating and it needs to be cooled OR replaced. Now if you do NOT have a heating problem, here is where things get difficult. First - go into your BIOS and select 'fail safe defaults'. Then, if you can, try different components one at a time. Disable your sound card and see if that makes a difference. Disable your network card. Try a different graphics card. Try a different power supply. Etc. If you're still not coming right, please don't post another plea here. Try techsupportforum.com, or go and support your local computer shop. Yes, sometimes you have to pay to fix problems, such as when you pay a mechanic to fix your car. Sandman30s (talk) 20:10, 3 August 2009 (UTC)

• Well, Ive downloaded its exe file and run it. It shows my CPU=27C, Mainboard=40C. But I could not find GPU and Harddisk temprature option. where are they? Thank you--119.30.36.33 (talk) 22:08, 3 August 2009 (UTC)

They should be right there, below CPU. Maybe your motherboard doesn't have sensors for these other things, maybe the sensors are broken, etc. Mainboard=40C could signify that something else, like the GPU or HD is causing it to overheat. I'm not sure if your ATI card comes with a temperature sensor - I'm curious to know how hot it is. Overheating can cause things to freeze... but funny that your dvd icon disappears?! Weird. You can also try backing up your data, formatting your drive and reinstalling windows... but I suspect either a hardware or heating problem. In my experience when I've had problems like these, it was the hardware that was at fault. We should stop blaming poor windows for everything :) Sandman30s (talk) 13:40, 4 August 2009 (UTC)

Mainboard hotter than CPU sounds odd - I assume that the motherboard contains the chips that cover serial devices and sound - so it might be that. Have you checked all the fans, and the heatsinking on the motherboard. Also what was the upgrade.83.100.250.79 (talk) 14:19, 4 August 2009 (UTC)

Are you overclocking - if so stop - that could cause problems even if it is not overheating. Also is it a new problem - have you added any new devices - sounds similar to problems caused by having an underspecified power supply (amongst a 1000 other things). It's good that it runs for over 6hrs before problems - suggests the computer is not borked. 83.100.250.79 (talk) 23:23, 3 August 2009 (UTC)

Actually all those problems (DVD, mouse, keyboard) are serial devices - you might want to focus on that area eg troubleshoot drivers etc.83.100.250.79 (talk) 00:07, 4 August 2009 (UTC)

• I have reinstalled windows again from vista to XP. But same thing is happening. I have checked all the fans. They are running properly. I am not overclocking but thinking to under clocking. My PSU is Thermaltake 750W. Is there any way to cooling down mainboard? Should I reduce GPU Clock of Graphics Card to avoid overheating?
  

Update: I have Just checked Graphics card temperature with CPUID Hardware Monitor software. It showed GPU Core temperature is 61*C (Value), 61*C (Min) 62*C (Max) and HDD temperature is 29*C (Value, Min and Max). One more thing I want to know is how in BIOS "fail safe defaults" option works. If I choose it will all drivers work properly?Thank you. --119.30.36.42 (talk) 17:48, 4 August 2009 (UTC)

61C is pretty hot if you haven't just run a game or something graphically intense. If you choose fail safe defaults everything will still work - the advantage of choosing this will be if you overclocked by mistake, everything will default back to how the manufacturer set it... most machines run off these defaults so unless you had a reason to change anything, you should be safe. I would take that graphics card back and get it tested or swapped - 61C is too hot for just running windows. Sandman30s (talk) 19:05, 4 August 2009 (UTC)

Actually, some people argue that 60C is OK and over 70C is too hot for ordinary windows operations. It's up to you. If those fail safe defaults don't work, then get the graphics card tested or swapped if you can. Sandman30s (talk) 19:11, 4 August 2009 (UTC)

YES [2] these got 58C on idle for a 4890 - I don't think it's the graphics card. It sounds like some serial chip is going on the blink to me.83.100.250.79 (talk) 19:47, 4 August 2009 (UTC)

Potentially you should close the case, and let the convection design work properly. Power supply sounds big enough, there shouldn't be a need to underclock. As mentioned above the machine should detect overheating and take action, (eg shut down or throttling).

Question what are the temperatures when it starts to go wrong.?83.100.250.79 (talk) 19:44, 4 August 2009 (UTC)

also does this apply to you? [3]<quote>So for you buyers of a 4890 card out there - be aware that your regular run of the mill ATX midtower case may be overwhelmed by the amount of heat this card puts out</quote> —Preceding unsigned comment added by 83.100.250.79 (talk) 19:50, 4 August 2009 (UTC)

eBooks

Can all PCs display all eBooks? • S • C • A • R • C • E • 18:41, 3 August 2009 (UTC)

No. A lot of eBooks are distributed only for hardware readers (chiefly Amazon's Kindle and Sony's reader) can only be read on those devices, not on PCs. -- Finlay McWalter • Talk 18:46, 3 August 2009 (UTC)

Is there any free way to split PDF pages down the middle?

I have a scanned PDF book with 2 pages on each page. Is there any way I could split the whole doc down the middle so there is 1 book page per page. --Gary123 (talk) 21:37, 3 August 2009 (UTC)

The Gimp will import PDFs and then you can manipulate them as you want.--80.176.225.249 (talk) 21:56, 3 August 2009 (UTC)

...which is exceptionally cumbersome for more than just one page. --98.217.14.211 (talk) 22:29, 3 August 2009 (UTC)

It's not easy to do, unfortunately. I've long struggled with the same problem. You can chain a number of free command-line programs (e.g. ImageMagick, pdftk) to do the actions for you, but it is slow and takes a LOT of fiddling. I had some success with using OS X's Automator to effectively just double the pages (so that the output PDF was 1,1, 2,2), and then use Acrobat (not free) to crop "even only" and "odd only", but this is also cumbersome. So far I don't think there's an easy solution to this even though it is a common-enough activity if you scan books or articles on a regular basis (which a lot of people do).

And just to reiterate, so that others are sure what you mean: if you scan a book on a flatbed scanner, you get one page of PDF that has two pages of book on it. The ideal program would create a new PDF where the left and right pages were separated. Effecting this manually is extraordinarily time consuming. --98.217.14.211 (talk) 22:29, 3 August 2009 (UTC)

I know it is not what the OP asked, but would you normally want such software to take the original pdf file, and create two consecutive pages from each source page;thereby recreating the original book in page-by-page order? I would be surprised if software for that task doesn't exist. Astronaut (talk) 04:14, 4 August 2009 (UTC)

That's exactly what we are talking about. And yeah, it seems like something that would be easily handled, but alas, it is not. (Why not? Because there is actually precious little software that can actually read—not just make—PDFs. PDF is a tough format and there are only a couple open codebases around that do anything with it, and the number of programs that give you content-level control over them is pretty small. Programs like ImageMagick can let you render individual pages into raster images, while programs like pdftk let you manipulate the internal structure of PDFs, when what we need here is something that easily lets you do both at the same time.) --98.217.14.211 (talk) 15:03, 4 August 2009 (UTC)

Could it be ... because PDF is an antiquated, proprietary format held over from the days when every brand of printer needed its own programming language, and foisted upon an unsuspecting public who doesn't understand the technical details, via an aggressive marketing campaign, unethical business collusion, and vendor lock-in? Nimur (talk) 16:20, 4 August 2009 (UTC)

The PDF is the best cross-platform document format I know of. It offers several advantages over other formats such as DJVU. These include lossless JPEG2000 compression and vector objects. Bookmarks make it ideal for books. I have tried distributing read-me files in RTF, but Linux systems render them inaccurately. So, I now distribute all read-me files as PDFs. They not only display consistently across platforms, but print consistently from printer to printer. A PDF is a faithful print preview. Publishers also like them because they are hard to edit. So, they are able to protect their intellectual property more easily. The success of the PDF has little to do with the factors you just mentioned.--WinRAR anodeeven (talk) 04:57, 5 August 2009 (UTC)

Maybe. But if programmers would take the existing PDF reading code out there, like Xpdf and turn it into a free, easy-to-use API, then it would be a lot easier for others to exploit. As it is, most of the people who have bothered to use the xPDF code have either turned it into vanilla readers or tools that are meant to compete with Acrobat and sell for hundreds of dollars. So we're left in the cold. The code is out there... but nobody has bothered to make it very easy to use. Port xpdf to something easier to script with than Java and we'll be in business, I'll write the dang app myself. Baaaaddd programmers. --98.217.14.211 (talk) 18:16, 4 August 2009 (UTC)

I agree, 98. I mucked with some PDFTK code a while back, and it's no fun at all. I don't know what the prospects are for making this tenable, but I'm hoping that the slew of new open document formats will simply replace PDF. Nimur (talk) 04:45, 5 August 2009 (UTC)

The article on Portable Document Format documents PDF as an open standard. Is the article wrong, or are you spreading FUD, or am I presenting a false dichotomy in suggesting those are the choices? The reference desk is not a soap box, even if you use <small> to advance your views. 62.78.198.48 (talk) 18:55, 4 August 2009 (UTC)

Yes and what exactly is the "unethical business collusion" refering to. Yours sincerely, adobe lawyer.83.100.250.79 (talk) 19:39, 4 August 2009 (UTC)

Maybe I was on the edge of soap-boxing, but I am not the first to use these terms to describe the unethical (and in some cases, illegal) marketing of PDF and other Adobe technologies practices:

• Adobe-FedEx Kinko's: Convenience and collaboration, or collusion and security breach?.
• "Adobe may have its own legal problems.....swearing out a false statement that caused incarceration and prosecution."
• "How long before Adobe turns it legal team on XPDF (violating a possible tradmark on the letters P, D, & F)?"

So, it may have been soap-boxing, or it may not have been - that is for you to decide - but these are hardly fringe ideas. You can easily investigate these topics for yourself and form your own opinion. Perhaps it's FUD, or maybe I'm just a concerned computer-user. Nimur (talk) 04:38, 5 August 2009 (UTC)

It's worth remembering that although PDF is an open standard now, it wasn't for a long time (only a defacto but propriety standard). Also Adobe owns patents relating to PDF but has agreed not to sue provided the application complies with the PDF spec. I'm not sure but I believe Adobe's conditions were stricter or perhaps just unclearer in the past before they agreed to release PDF as an international standard. I don't know the specific reasons why Adobe decided to make PDF into an open standard however I seem to recall that when I looked in to it, Microsoft had made clear their intentions to develop XPS and possibly even to make it into an open standard before Adobe annouced they intended to submit PDF to the ISO which has always made me wonder Microsoft's plans were part of the reason Adobe decided to make PDF an international standard. Finally during the development of Office 2007, Microsoft had planned to make "Save to PDF" available in Office by default but Adobe threated to sue them [4]. Microsoft eventually agreed to make it an optinional download, although I believe they've now reached another agreement so it will be available by default in 2010 and I think is installed with one of the service packs. I was never able to ascertain precisely what Adobe's threat was, whether it was alleged Microsoft's implementation didn't comply with the standard (seems unlikely since this was never mentioned) or perhaps more likely Adobe was arguing MS was abusing their monopoly position again. (I believe Adobe had already started the standarisation process by that time and agreed not to sue anyone developing a spec complaint implementation). Nil Einne (talk) 14:14, 7 August 2009 (UTC)

It would still be cumbersome because you would have have to interlineate after, but if you have adobe professional you can just take the document and duplicate it. Then take the first document entire and crop all the pages from the left edge in one function so that one side of the document i.e. one page width is cropped away. Then take the duplicated document and crop all the pages from the right edge edge in the same manner. Then you'd have two documents, one with all the odd pages and one with all the even pages. Then you'd have to interlineate back to order. The first part would take moments but the second would be a pain.--Fuhghettaboutit (talk) 05:10, 5 August 2009 (UTC)