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  • Improving method to read signed 8-bit integers from hexadecimal.

    - by JYelton
    Scenario: I have a string of hexadecimal characters which encode 8-bit signed integers. Each two characters represent a byte which employ the leftmost (MSB) bit as the sign (rather than two's complement). I am converting these to signed ints within a loop and wondered if there's a better way to do it. There are too many conversions and I am sure there's a more efficient method that I am missing. Current Code: string strData = "FFC000407F"; // example input data, encodes: -127, -64, 0, 64, 127 int v; for (int x = 0; x < strData.Length/2; x++) { v = HexToInt(strData.Substring(x * 2, 2)); Console.WriteLine(v); // do stuff with v } private int HexToInt(string _hexData) { string strBinary = Convert.ToString(Convert.ToInt32(_hexData, 16), 2).PadLeft(_hexData.Length * 4, '0'); int i = Convert.ToInt32(strBinary.Substring(1, 7), 2); i = (strBinary.Substring(0, 1) == "0" ? i : -i); return i; } Question: Is there a more streamlined and direct approach to reading two hex characters and converting them to an int when they represent a signed int (-127 to 127) using the leftmost bit as the sign?

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  • How Can I: Generate 40/64 Bit WEP Key In Python?

    - by Aktariel
    So, I've been beating my head against the wall of this issue for several months now, partly because it's a side interest and partly because I suck at programming. I've searched and researched all across the web, but have not had any luck (except one small bit of success; see below), so I thought I might try asking the experts. What I am trying to do is, as the title suggests, generate a 40/64 bit WEP key from a passphrase, according to the "de facto" standard. (A site such as [http://www.powerdog.com/wepkey.cgi] produces the expected outputs.) I have already written portions of the script that take inputs and write them to a file; one of the inputs would be the passphrase, sanitized to lower case. For the longest time I had no idea what the defacto standard was, much less how to even go about implementing it. I finally stumbled across a paper (http://www.lava.net/~newsham/wlan/WEP_password_cracker.pdf) that sheds as much light as I've had yet on the issue (page 18 has the relevant bits). Apparently, the passphrase is "mapped to a 32-bit value with XOR," the result of which is then used as the seed for a "linear congruential PRNG (which one of the several PRNGs Python has would fit this description, I don't know), and then from that result several bits of the result are taken. I have no idea how to go about implementing this, since the description is rather vague. What I need is help in writing the generator in Python, and also in understanding how exactly the key is generated. I'm not much of a programmer, so explanations are appreciated as well. (Yes, I know that WEP isn't secure.)

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  • How to read/write high-resolution (24-bit, 8 channel) .wav files in Java?

    - by dB'
    I'm trying to write a Java application that manipulates high resolution .wav files. I'm having trouble importing the audio data, i.e. converting the .wav file into an array of doubles. When I use a standard approach an exception is thrown. AudioFileFormat as = AudioSystem.getAudioFileFormat(new File("orig.wav")); --> javax.sound.sampled.UnsupportedAudioFileException: file is not a supported file type Here's the file format info according to soxi: dB$ soxi orig.wav soxi WARN wav: wave header missing FmtExt chunk Input File : 'orig.wav' Channels : 8 Sample Rate : 96000 Precision : 24-bit Duration : 00:00:03.16 = 303526 samples ~ 237.13 CDDA sectors File Size : 9.71M Bit Rate : 24.6M Sample Encoding: 32-bit Floating Point PCM Can anyone suggest the simplest method for getting this audio into Java? I've tried using a few techniques. As stated above, I've experimented with the Java AudioSystem (on both Mac and Windows). I've also tried using Andrew Greensted's WavFile class, but this also fails (WavFileException: Compression Code 3 not supported). One workaround is to convert the audio to 16 bits using sox (with the -b 16 flag), but this is suboptimal since it increases the noise floor. Incidentally, I've noticed that the file CAN be read by libsndfile. Is my best bet to write a jni wrapper around libsndfile, or can you suggest something quicker? Note that I don't need to play the audio, I just need to analyze it, manipulate it, and then write it out to a new .wav file. * UPDATE * I solved this problem by modifying Andrew Greensted's WavFile class. His original version only read files encoded as integer values ("format code 1"); my files were encoded as floats ("format code 3"), and that's what was causing the problem. I'll post the modified version of Greensted's code when I get a chance. In the meantime, if anyone wants it, send me a message.

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  • Pygame surfaces and their Rects

    - by Jaka Novak
    I am trying to understand how pygame surfaces work. I am confused about Rect position of Surface object. If I try blit surface on screen at some position then Surface is drawn at right position, but Rect of the surface is still at position (0, 0)... I tried write my own surface class with new rect, but i am not sure if is that right solution. My goal is that i could move surface like image with rect.move() or something like that. If there is any solution to do that i would be happy to read it. Thanks for answer and time for reading this awful English If helps i write some code for better understanding my problem. (run it first, and then uncomment two lines of code and run again to see the diference): import pygame from pygame.locals import * class SurfaceR(pygame.Surface): def __init__(self, size, position): pygame.Surface.__init__(self, size) self.rect = pygame.Rect(position, size) self.position = position self.size = size def get_rect(self): return self.rect def main(): pygame.init() screen = pygame.display.set_mode((640, 480)) pygame.display.set_caption("Screen!?") clock = pygame.time.Clock() fps = 30 white = (255, 255, 255) red = (255, 0, 0) green = (0, 255, 0) blue = (0, 0, 255) surface = pygame.Surface((70,200)) surface.fill(red) surface_re = SurfaceR((300, 50), (100, 300)) surface_re.fill(blue) while True: for event in pygame.event.get(): if event.type == QUIT: return 0 screen.blit(surface, (100,50)) screen.blit(surface_re, surface_re.position) #pygame.draw.rect(screen, white, surface.get_rect()) #pygame.draw.rect(screen, white, surface_re.get_rect()) pygame.display.update() clock.tick(fps) if __name__ == "__main__": main()

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  • Why are my 2 new windows 7 (64 bit) workstations taking over 10 minutes to log on to the SBS 2008 do

    - by Howie Hughes
    Hi, we have a SBS 2008 domain. On this we have windows XP clients. However, we are testing the windows 7 (64 bit) machines on the network. It takes between 10 & 15 minutes to log on - every time! I have checked the event logs on the client machine, and the only error I can see is; Event ID: 6005 The winlogon notification subscriber is took 615 seconds to handle the notification event (CreateSession). I have no warnings in the server event log, everything pings ok by name, so am guessing DNS is fine. Can someone please lend a hand with this, as we really want to go with windows 7. Lastly, both the server, and the windows 7 machines are fully patched and updated. Thank you.

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  • Problem installing Ubuntu 10.04 64 bit side by side with Vista by using a bootable USB drive. What n

    - by Adam Siddhi
    What happened I decided to install Ubuntu 10.04 64 bit side by side with Vista Home Premium (I guess on another partition) with a USB stick. I found instructions on how to do this here: https://help.ubuntu.com/community/Installation/FromUSBStick To create the bootable USB drive I had to download a program called Unetbootin. That process was simple enough. All I had to do was just choose the disk image option, select the ubuntu-10.04-desktop-amd64.iso image, make sure it recognizes my USB drive and then press OK. It takes only like a few minutes to create a working bootable USB drive. Then I have to restart my computer, enter the BIOS, select my USB drive as the first boot drive, save options and continue with booting up. After this Ubuntu actually loads up. I think this is known as the Live version of Ubuntu so you can try it out before fully installing it. Any ways, on the Ubuntu 10.04 desktop I saw an installer. I click it and begin the installation process. Just so you know, I tried installing it 2 times. I will explain what happened each time: The first time I tried installing Ubuntu 10.04 I got stuck at step 4 of 7. I remember selecting the last option in the window which was Specify Partitions Manually (Advanced) I made my partition for Ubuntu like 52 gigs. I clicked forward and a little pop up window appeared saying Please Wait. So the installation process stalled on this window so I closed out of it and quit the installation process. So at this point I was worried because I had already selected the partition size and assumed it started making it. Since it stalled I had to quit out though. Anyways, once again I reached step 4 of 7 a decided to select the first option which is Install them side by side choosing between them each startup. I figured this was the safe way to go. I did that and the pop up window saying Please Wait popped up again but lasted only like 10 seconds. Then I got to I guess step 6 where it asks you to enter your desired name and password. Did that and clicked forward. The Ubuntu 10.04 installation load screen appeared and the loading bar at the bottom started filling up. So I got to 83% and stalled during the Importing other profile information (I think it was called this. I had the option to do this during I think step 6) process. So at this point I decided to get stop the installation process. I was getting very nervous. I tried to restart the computer but all that happened was that Ubuntu restarted. I finally got the computer to restart. I was pretty sure I had screwed something up big time by this point. As my computer was restarting I entered BIOS again and switched back to it booting from my main hard drive containing Vista. Saved it and continued the boot process. My worst fears were confirmed as Vista would not boot up. I mean I saw the little Microsoft Windows choppy animated green loading bar at the bottom of the screen and then boom! It decided to restart. When it restarted I had the option to run a memory test check to see if there was anything that needed to be repaired. That took like 20 minutes and at the end I saw that I did indeed have to repair something. I had to go through 2 repair processes. After each I had to restart the computer. The 2nd time it went through the repair process it said that it could not fully repair the damage. I was scared and restarted but Vista did load up. I got to my desktop and saw a message saying something like Repairs have been made, Please restart for changes to take effect I noticed that some Notification icons were missing and I could not hear volume in a video. Things were a bit funky. So I did restart and here I am. Now what?! So since I got back into Vista and thankfully have a working Internet connection I am trying to find answers to my problem (that is why I am writing this post). I am scared that I have partioned my hard drive 2 times after researching Installing Ubuntu 10.04 and seeing this post http://techie-buzz.com/foss/ubuntu-10-04-lts-installation-guide.html The author shows screen shots of installing Ubuntu 10.04. He shows the image of step 4 of 7 with a caption at the bottom. I will recreate it below: Select a partitioning option. Unless you want to format all the hard drive and install Ubuntu afresh, select the last option and proceed. Questions If I have indeed partitioned my HD 2 times (which I am sure it is), how do I get to a point where I can see all my bad, unfinished Ubuntu partitions and get rid of them? How do I clean this big mess up? & How can I ensure that this mess will not happen next time I try installing Ubuntu 10.04? Thank you Adam

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  • Is it possible to run pgp 6.5.8 freeware on Windows 7 64 bit machine?

    - by Johnny Holmes
    I am trying to get the PGP Command Line -Freeware Version 6.5.8 by Networks Associates working on a Wndows 7 64 bit machine. Does anyone know if it is possible? I installed it in C:\pgp when i run pgp, it keeps telling me that it can't find the pgp.cfg file. My PGPPATH is defined and set to C:\pgp I have also included this path in my Path variable Can anyone tell me what i am doing wrong. The documentation states that: "The first time you start PGP, the software checks to see if the environment variable PGPPATH is defined. If PGPPATH is defined, the software puts the pgp.cfg in the %PGPPATH% directory" Edit: This is most likely a Windows 7 professional folder rights issue, since the file pgp.cfg can't get written. I tried my best given the folder full rights, but im not 100% confident that i did it right. Anyone help me?

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  • Ubuntu 9.10 x64 has no sound, while Ubuntu 9.04 32 bit does.

    - by Macha
    I installed Ubuntu 9.10 x64 recently. Up until now I've been on 32 bit Ubuntu. For the first time since installing it, I went and tried to play a Youtube video. There was no sound. So a quick test to the system reveals that nothing will play sound (And I've tried turning the volume too full, as some have said output is quite quiet, but there is no sound at all). Further research shows that in sound preferences, the only output device listed was Dummy Output. Why would it work in 9.04 x86 and not 9.10 x64? While booting up, and occasionally with the sound preferences dialog open, I get a loud click (even though it isn't recognising my sound card). It's a Dell Studio 17 laptop. I'm not sure what the exact model of sound card is.

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  • Small 64-bit linux server distro with low memory footprint?

    - by djangofan
    I am looking for a linux server distro with a low memory footprint. I usually use Ubuntu but I need something with a smaller footprint in order to run a large Java JVM service inside of it and also run X-windows. Any ideas? The Java service needs to handle a 3GB memory heap and so I require a 64-bit OS and JRE. http://en.wikipedia.org/wiki/Comparison%5Fof%5FLinux%5Fdistributions I am thinking that ArchLinux is the only one that I can find right now. It uses 250MB out of the box (without X-win). Any better suggestions?

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  • Why Windows Media Center (Vista 32-bit) unable to record TV Series?

    - by Alex R
    I can record individual shows just fine, but trying to setup the recording of a Series throws an error (something like, "unable to schedule, try restarting Media Center", pops up in the bottom right of the screen). Trying to access the "Other Showings" menu causes Media Center to crash ("check for a solution online" dialog comes up). The machine is a fresh reinstall of 32-bit Windows Vista from the HP recovery CDs, plus all Microsoft updates and service packs. Hardware: HP s3220n, AMD X2 5000+, 2GB RAM, 300GB free space on disk. Media Center came bundled. The "Media Center update for Vista" failed to install (it says, not appropriate for my computer). Any ideas? Thanks

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  • How to set MinWorkingSet and MaxWorkingSet in a 64-bit .NET process?

    - by Gravitas
    How do I set MinWorkingSet and MaxWorking set for a 64-bit .NET process? p.s. I can set the MinWorkingSet and MaxWorking set for a 32-bit process, as follows: [DllImport("KERNEL32.DLL", EntryPoint = "SetProcessWorkingSetSize", SetLastError = true, CallingConvention = CallingConvention.StdCall)] internal static extern bool SetProcessWorkingSetSize(IntPtr pProcess, int dwMinimumWorkingSetSize, int dwMaximumWorkingSetSize); [DllImport("KERNEL32.DLL", EntryPoint = "GetCurrentProcess", SetLastError = true, CallingConvention = CallingConvention.StdCall)] internal static extern IntPtr MyGetCurrentProcess(); // In main(): SetProcessWorkingSetSize(Process.GetCurrentProcess().Handle, int.MaxValue, int.MaxValue); Update: Unfortunately, even if we do this call, the garbage collection trims the working set down anyway, bypassing MinWorkingSet (see "Automatic GC.Collect() in the diagram below). Question: Is there a way to lock the WorkingSet (the green line) to 1GB, to avoid the spike in page faults (the red lines) that occur when allocating new memory into the process? p.s. Every time a page fault occurs, it blocks the thread for 250us, which hits application performance badly.

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  • Problems running Java SWT application. Is this something to do with 64 vs 32-bit libraries?

    - by ?????
    I'm getting started with SWT Exception in thread "main" java.lang.UnsatisfiedLinkError: no swt-cocoa-3557 or swt-cocoa in swt.library.path, java.library.path or the jar file at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source) at org.eclipse.swt.internal.Library.loadLibrary(Unknown Source) at org.eclipse.swt.internal.C.<clinit>(Unknown Source) at org.eclipse.swt.internal.cocoa.NSThread.isMainThread(Unknown Source) at org.eclipse.swt.graphics.Device.<init>(Unknown Source) at org.eclipse.swt.widgets.Display.<init>(Unknown Source) at org.eclipse.swt.widgets.Display.<init>(Unknown Source) at org.eclipse.swt.widgets.Display.getDefault(Unknown Source) at com.astrobetty.getotagdesktop.MainUIWindow.main(MainUIWindow.java:110) I've carefully followed the directions here http://www.eclipse.org/swt/eclipse.php I can see libswt-awt-cocoa-3557.jnilib, libswt-cocoa-3557.jnilib, libswt-pi-cocoa-3557.jnilib clearly listed under "Referenced Libraries" in my Eclipse package explorer. Presumably, that should make them available on the classpath when I select the java module that contains "main" and do a "run as" application. What's the problem? I suspect it may be related to 64-bit vs 32-bit VMs....

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  • How do I load SciLexer.dll in Visual Studio 2008 Designer, on Windows 7 64-bit?

    - by Filini
    We develop a WinForm application using Scintilla.NET (1.7) component, which uses SciLexer.dll (unamnaged). At run-time, we distribute both 32bit and 64bit SciLexer.dll, and we load the correct one when the application starts (everything works fine). On our new development environments (Windows 7 64-bit), all our solutions build and run just fine, but the WinForm visual designer does not load our forms/controls which use Scintilla.NET, because it cannot load the correct SciLexer.dll: Window class name is not valid. at System.Windows.Forms.NativeWindow.WindowClass.RegisterClass() at System.Windows.Forms.NativeWindow.WindowClass.Create(String className, Int32 classStyle) at System.Windows.Forms.NativeWindow.CreateHandle(CreateParams cp) at System.Windows.Forms.Control.CreateHandle() at System.Windows.Forms.Control.get_Handle() at Scintilla.ScintillaControl.SendMessageDirect(UInt32 msg, IntPtr wParam, IntPtr lParam) at Scintilla.ScintillaControl.SendMessageDirect(UInt32 msg) at Scintilla.ScintillaControl.get_CodePage() at Scintilla.ScintillaControl..ctor(String sciLexerDllName) at Scintilla.ScintillaControl..ctor() Where does Visual Studio 2008 look for unmanaged libraries? I tried putting the 64-bit SciLexer.dll in SysWOW64, in the folder where ScintillaNET.dll is referenced, adding a folder in PATH system variable, adding a folder reference in the project, but I keep getting this error. Any help is appreciated.

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  • Why 2 GB memory limit when running in 64 bit Windows ?

    - by Roland Bengtsson
    I'm a member in a team that develop a Delphi application. The memory requirements are huge. 500 MB is normal but in some cases it got out of memory exception. The memory allocated in that cases is typically between 1000 - 1700 MB. We of course want 64-bits compiler but that won't happen now (and if it happens we also must convert to unicode, but that is another story...). My question is why is there a 2 GB memory limit per process when running in a 64 bit environment. The pointer is 32 bit so I think 4 GB would be the right limit. I use Delphi 2007.

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  • Faster way to convert from 24 bit wav pcm format to float?

    - by LMO
    I need to read data in from a wav file in 24 bit pcm format, and convert to float. I'm using Python 2.7.2. The wave package reads the data in as a string, so what I've tried is: # read in entire wav file wdata = f.readframes(nFrames) # unpack into signed integers and convert to float data = array.array('f') for i in range(0,nFrames*3,3): data.append(float(struct.unpack('<i', '\x00'+ wdata[i:i+3])[0])) # normalize sample values data = data / 0x800000 This is quite a bit faster than my earlier approaches, but still quite slow. Can anyone suggest a more efficient method?

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  • NASM: Count how many bits in a 32 Bit number are set to 1.

    - by citronas
    I have a 32 Bit number and want to count know how many bits are 1. I'm thinking of this pseudocode: mov eax, [number] while(eax != 0) { div eax, 2 if(edx == 1) { ecx++; } shr eax, 1 } Is there a more efficient way? I'm using NASM on a x86 processor. (I'm just beginning with assembler, so please do not tell me to use code from extern libraries, because I do not even know how to include them ;) ) (I just found http://stackoverflow.com/questions/109023/best-algorithm-to-count-the-number-of-set-bits-in-a-32-bit-integer which also contains my solution. There are other solutions posted, but unfortunatly I can't seem to figure out, how I would write them in assembler)

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  • How can I access the sign bit of a number in C++?

    - by Keand64
    I want to be able to access the sign bit of a number in C++. My current code looks something like this: int sign bit = number >> 31; That appears to work, giving me 0 for positive numbers and -1 for negative numbers. However, I don't see how I get -1 for negative numbers: if 12 is 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 1100 then -12 is 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 1111 0011 and shifting it 31 bits would make 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0000 0001 which is 1, not -1, so why do I get -1 when I shift it?

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  • How to reliably specialize template with intptr_t in 32 and 64 bit environments?

    - by vava
    I have a template I want to specialize with two int types, one of them plain old int and another one is intptr_t. On 64 bit platform they have different sizes and I can do that with ease but on 32 bit both types are the same and compiler throws an error about redefinition. What can I do to fix it except for disabling one of definitions off with preprocessor? Some code as an example: template<typename T> type * convert(); template<> type * convert<int>() { return getProperIntType(sizeof(int)); } template<> type * convert<intptr_t>() { return getProperIntType(sizeof(intptr_t)); } //this template can be specialized with non-integral types as well, // so I can't just use sizeof() as template parameter. template<> type * convert<void>() { return getProperVoidType(); }

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  • How do you specify a 64 bit unsigned int const 0x8000000000000000 in VS2008?

    - by Mark Franjione
    I read about the Microsoft specific suffix "i64" for integer constants. I want to do an UNsigned shift to a ULONGLONG. ULONGLONG bigNum64 = 0x800000000000000i64 >> myval; In normal C, I would use the suffix "U", e.g. the similar 32 bit operation would be ULONG bigNum32 = 0x80000000U >> myval; I do NOT want the 2's complement sign extension to propogate through the high bits. I want an UNSIGNED shift on a 64 bit const number. I think my first statement is going to do a SIGNED shift right. I tried 0x800000000000000i64U and 0x800000000000000u64 but got compiler errors.

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  • Is there a way to have a bit bucket pointer? (C/C++)

    - by Crazy Chenz
    Is there a way to have a bit bucket pointer? A lot of IO (specifically input related) system calls return data to a buffer of a specific size. Is there a trick or way to make a sorta bit bucket pointer, so I can accept any amount of data that will be thrown away. Doing something like "char tmp[INT_MAX]" is crazy. The behavior I am looking for is something like /dev/null, only in a pointer world. Not to hopeful on this.... just curious. Thanks, Chenz UPDATE: Perhaps mmap-ing /dev/null. Forgot about that when I asked the question.

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  • For LinqToSQL is 0 true or is 1 (for type Bit)?

    - by Vaccano
    I have a column of type Bit (called BBoolVal in this example). I have a LinqToSQL Statement Like this: var query = List<MyClass> myList = _ctx.DBList .Where(x => x.AGuidID == paramID) .Where(x => x.BBoolVal == false); When I look at the sql it ends up like this (I added the spacing and changed the names): SELECT [t0].[Id], [t0].[AGuidID], [t0].[OtherIDID], [t0].[TimeColumn], [t0].[BBoolVal], [t0].[MoreID] FROM [dbo].[MyTable] AS [t0] WHERE (NOT ([t0].[BBoolVal] = 1)) AND ([t0].[AGuidID] = @p0) Because my x.BBoolVal == false translates to [BBoolVal] == 1 I gather that false = 1 (and thus true = 0). I am asking because this seems a bit backwards to me. I am fine to accept it, I just want to be sure.

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