I need to read repeatedly data from a MPEG2 file to the buffer of 188 bytes and analyse data bit by bit.
I have the problem with correct bytes reading from file. In my code listed below I have two methods for that.
First one is lossing this bytes which in hex_base mode have 0 at the begining, eg: 03, 0F, etc.
The second method based on read function which need to have buffer as a char (lenght > 1 byte). Because of that I receive different values from that from file in some cases.
How can I properly read such file?
Code:
#include <iostream>
#include <fstream>
#include <stdlib.h>
#include <windows.h>
using namespace std;
int main() {
fstream plik_in;
#include <stdio.h> #include <stdlib.h> int main(int argc, int * argv) { char buffer[16]; FILE *fp; unsigned long long test; unsigned char key[16]; fp = fopen("D:key.txt","r");
[code].....
i searched for a code for reading bytes from a file and i found this one but when i run the program, it doesn't return the bytes written in the file, it returns another bytes / what is the problem?
have udp server-client application written in C. On the client side packet loss is detected using recvfrom function and sequence numbers of packets. How can I now simulate dropped packet's on the client side, for example if server is sending 1000 packet I want to drop 20% of them? I want to do this in the code, not for example using ip tables or WANEM or something like that. And one more thing, I have few clients and I want that they can dropped different packets, not the same one.
Code: while(1){ nbytes = recvfrom(socket, buffer, MAX_SIZE, 0, (struct sockaddr *) &srv_addr, &addrlen); if (nbytes != -1) { // packet is received
write codes that could solve a quadratic formula, and my codes are like this:
#include <bjarne/std_lib_facilities.h> int main() { cout << "Enter the coefficients of a quadratic polynomial a*x**2 + b*x +c: "; cout << " a? "; double a; cin >> a; cout << " b? ";
[code]....
Which runs perfectly, but I have 2 questions:
1. How to simplify these code? On the assignment sheet the professor wrote about using void solve_linear(double b, double c); and void solve_ quadratic (double a, double b, double c);which I currently dont understand how these works. He asked us to write a well-encapsulated (as short as possible) program.
2. These are for extra points: the precision problem of floating numbers: professor asked us to find a way to get the precise answer of it, like this: Enter the coefficients of a quadratic polynomial a*x**2 + b*x +c: a? 1 b? -20000 c? 1.5e-9 Trying to solve the quadratic equation 1*x*x + -20000*x + 1.5e-09 == 0 Using classical formula: Two roots, x = 20000 and x = 0 Using stable formula: Two roots, x = 20000 and x = 7.5e-14
My guess is that A. Using code like if(x1*x2=a/c) to check if numbers were approximated. B. Somehow determine the larger one in x1 and x2. C. Somehow use that larger one to do something
I have an object that I use to store data. Two of its members are dynamic arrays. When passed (by reference) to a function used to fill the arrays with data, everything works fine. However, only the 0th index of the arrays remain populated after the function call.
Im using some motors which run off PWM pins.Theres a High byte and Loq byte register (PWMH,PWML).I have an int which i need to put into these registers but i dont know how???so for example
I am encoding some information in a binary file, and I want to check what I am doing by printing out all the bytes that represent the file.
This is being done by opening a pointer to the file with fopen, reading in each byte of data as a char, and then writing this char to the screen.
I have some image files (e.g. "image.jpg"), whose structure I know, so that I can test my program.
When I print out the chars, they are initially correct, and follow the structure of the file as expected.
However, after about 40 bytes, I find that every subsequent character is ' ' i.e. a blank character.
I then created a CharToBin function, which allows me to print out the actual bits in the char. When doing this, it shows that all the bits are 1 for the characters. i.e. most of the file is represented by 1's, which is clearly not correct.
This happens on all the image files I have tested, and furthermore, on several other non-image files. They all start printing out ' ' after a while. However, all these files are fine and not corrupted, e.g. the image files display correctly.
Code: #include <fstream> #include <iostream> #include <sstring> #include <string> #include <stdio.h> using namespace std; string CharToBin(char ch) { bool bits[8]; for (int i = 0; i < 8; i++)
I have a FILE stream, and I want to create a function that streams a specified number of bytes (up to four bytes) and returns the value of this, as an integar.
For example, supposing that my FILE has the following data, in hex: 74 C8 02 33 F2 7B....... I then want to stream three bytes and store this as an integar. So, I want to stream "04 08 02". The data stored in the integar should then be "00 74 C8 02", because I have not streamed anything into the first byte. By converting the hex to dec, the integar should then be of the value 7653378 (if it is unsigned).
To try to achieve this, I have written the following function. I create an integar and initialise it to zero, then take each byte from the stream, and OR it with my integar. Then, I shift the integar left by 8, and read the next byte, and so on.
The problem is, when I convert "c" to "c_int", it adds on a load of 1's to the left of the "c" data. This then means that the OR comparison changes all those bits in my integar to 1.
How to solve this? I am also wondering whether there is a much more simple way of doing this, rather than having to write my own function....
Code: int StreamFileToInt(FILE *fp, int num_bytes) { char c; int c_int; int x = 0x0000; for (int i = 0; i < num_bytes; i++) {
I made this program to convert bits to bytes, because I'm so sick of seeing ISP's advertise speeds in megabits, which I consider an intentional attempt to decieve :P And I think I've finally understood how the return value of scanf works since the last time I posted here, so my program can check to see if an integer was entered before processing the input, but I'm stuck on how to make the whole program start over if an integer is not entered. I have a hunch it would involve a loop, but I can't figure out how to make the program start over at "How many mb do you need converted?" if an integer is not entered into scanf..Here is the code I have so far:
Code:
#include <stdio.h> int main () { int b, mb, kb, Byte, kB, mB, gB; char term; }
[code]....
and my program makes the assumption for now at least, that mb will be inputted because that's the unit of measurement that i usually see advertised, and i didn't bother making an if statement to print a conversion in terms of gigabytes because i've never heard of a connection that fast :P
How to delete certain bytes from middle of a binary file?
Those bytes are in fact of a struct.
One approach I found was to re-write the whole data except the struct I want to delete. But may be its not good one if file size is in gb and I will have to write complete data again.
how to combine two bytes (each byte is 8 bits wide) in order to get the original value. I am displaying values(from 0 to 500)sent from my microcontroller on the GUI.I can successfully display values from 0 to 255 as this requires just sending a byte. However sending values from 256 to 500 requires sending two bytes. The problem I am having is that I was unable to re-combine the received two bytes in order to get the original value. Below are my lines of code:
int main( void ) // this is the main function inside the microcontroller { sei(); USI_TWI_Master_Initialise(); Spi_Master_Init(); while(1) // I am using this loop to send 500(111110100) { Transmitt_Receive(244);//this function sends LOW BYTE of 500(11110100) _delay_ms(1000);
[code]....
When I combined the two bytes using the above arrangements, instead of getting 500 my GUI displayed 62708.I got the same result when I used BitConverter.
I want to read a single byte from a wifstream. With an ifstream I would use read(), but given that the char type for an wifstream is wchar_t (2 bytes), this is also being used by read(), so how can I read a single byte from such a stream?
if (!WriteProcessMemory(Handle, (BYTE*)((DWORD)GetProcAddress(GetModuleHandle("ntdll.dll"), "LdrLoadDll")), &btLdrLoadDll, sizeof(btLdrLoadDll), NULL)) { CloseHandle(Handle); std::cout << " Failed to write Bytes to memory. Press enter to exit.";
I am a member of a group still developing the Microprose European Air War game. We have the source code and permission to do this. As the code dates back to 1998 I use Visual Studio 2006.
I have written many programs in Visual basic, and have the following one to read the airbase value in the "targets.dat" file. The file has a four byte header containing the number of tatgets, and a 32 byte data block containing the data for each target.
Private Sub Command1_Click() List1.Clear Dim nt As Long Dim a4() As Long Open App.Path & " argets.dat" For Binary Access Read As 1 'read and display the number of targets
[Code] ....
Despite many attempts I cannot write the C equivalent of this code into the eaw.exe source. All I really need to know is how to open the 'targets.dat' file and how to get the value of a byte (or integer, or long) at a given position as in the "Get #1, k, a4(n)" line.
Using a table with the 256 bytes as strings, said table is used as a reference in the 2 functions of this code. Functions who make the conversion such as the title establishes, and in the inverse way too.
The main advantage is that you don't need any knowledge about managing bytes with c++..
