Related to shifting bytes and byte manipulation. There are operators in most of the programming languages to shift bits which could be used to shift bytes.
Questions tagged [byte-shifting]
77 questions
1
vote
2 answers
Android Kotlin Byte Shifting +=
I'm trying to convert a BLE native Byte handling helper to Kotlin. In the process, I noticed that in
JAVA
myByteArray[offset] += (byte)(exponent & 0xFF);
it works as expected, but when converted to kotlin
KOTLIN
myByteArray[offset] += (exponent…
Sam
- 5,342
- 1
- 23
- 39
1
vote
2 answers
Shifting by a number is different than shifting by a variable
I have the following c code:
int foo = 0;
printf("output1: %08x\n", (~0x0) << (~0));
printf("output2: %08x", (~0x0) << (~foo));
which prints out:
output1: ffffffff
output2: 80000000
Why does shifting by the same number produce a different result?
Toby
- 140
- 6
1
vote
0 answers
Bytes shuffled while copying 2 bytes using memcpy
int main()
{
unsigned short crc = 0x00;
unsigned char buffer[4] = {0x01,0x02,0x72,0xAE};
memcpy((void *)&crc, (void *)&buffer[2],2);
printf("crc = 0x%x \n",crc);
return 0;
}
for above program i was expecting crc value to be…
Jack
- 694
- 8
- 20
1
vote
1 answer
C: Reading a whole file into buffer and byteswap the buf | ADDECEFA -> DEADFACE
EDIT: After doing some more research, it seems that what i actually need is big endian to middle endian and vice versa. so 12345678 -> 34127856 and back. Sorry for any confusion.
I have a small file, exactly 16MB. I am reading the whole file into a…
james28909
- 554
- 2
- 9
- 20
1
vote
1 answer
How to reverse bytes order in javascript Uint32
I need to send an ArrayBuffer via chrome.sockets.udp plugin.
The data is sent via Android ionic app to an emulator that runs on a computer.
I need to send the following fields:
var arrayBuffer = new ArrayBuffer(20);
var dv = new…
user2199630
- 203
- 1
- 2
- 12
1
vote
1 answer
How to combine two halves from two bytes to get a single byte
Let us say that byte1 = 00001111, and byte2 = 11110000. How would I take the second half of byte1, then take the first half of byte2 and combine them to get one byte of value 11111111. I have done some research, but I just cannot seem to wrap my…
Hobbs2000
- 311
- 1
- 6
- 19
1
vote
5 answers
How to fill high-end bits in a Java byte with '1' without knowing the last 1 in advance? (FAST FIX Negative Integer decoder)
I am writing a FIX/FAST decoder for negative numbers as described below:
My question is:
How to fill the high-end bits of a Java byte with 1s as it is described above? I am probably unaware of some bit manipulation magic I need to in this…
chrisapotek
- 6,007
- 14
- 51
- 85
1
vote
3 answers
retrieving bits from bytes
Hey so I was wondering if someone could explain how this works, I have to retrieve the 3rd bit from a byte, it is a bool value, and I i'm confused about how this actually works, and also if I have the syntax correct. I keep coming on so many…
user3681077
- 25
- 8
1
vote
1 answer
Swapping 2 Bytes of Integer
I have a method that receives 3 parameters: int x, int n, and int m. It returns an int with the nth and mth bytes of x swapped
x is just a normal integer, set to any value. n and m are integers between 0 and 3.
For example, let the hex…
the_pwner224
- 99
- 1
- 1
- 11
1
vote
1 answer
Bit shifting repeating pattern
I'm looking for a way to bit shifting this pattern:
6
24
96
All these numbers are multiples of 2 so I was thinking there would be a way to shift them
I want to shift them so I get the pattern but it keeps repeating possibly in a…
zacharoni16
- 305
- 1
- 4
- 16
1
vote
3 answers
Creating a ISO-8859-1 string from a HEX-string in Java, shifting bits
I am trying to convert a HEX-sequence to a String encoded in either, ISO-8859-1, UTF-8 or UTF-16BE. That is, I have a String looking like: "0422043504410442" this represents the characters: "Test" in UTF-16BE.
The code I used to convert between the…
ABeanSits
- 1,725
- 1
- 17
- 34
1
vote
6 answers
convert 24bit RGB to ARGB16
I have to read a 24bpp Bitmap and convert each pixel from RGB24 to ARGB16.
I used the following code,
#define ARGB16(a, r, g, b) ( ((a) << 15) | (r)|((g)<<5)|((b)<<10))
But I am not getting the required Output.
Any help would be highly…
green
- 107
- 1
- 6
- 13
0
votes
2 answers
What's the meaning of shifting in fixed-point arithmetic when implementing it in C++?
I have a problem with understanding fixed-point arithmetic and its implementation in C++. I was trying to understand this code:
#define scale 16
int DoubleToFixed(double num){
return num * ((double)(1 << scale));
}
double FixedToDoble(int…
th3plus
- 161
- 2
- 11
0
votes
1 answer
Python-numpy reading bytes and offset to signed int32
I have an operation to apply in python to more than 10 millions values. My problem is to optimise the actual operation.
I have 2 working methods, numpy and python vanilla.
Python vanilla operation:
1: My raw value is a 4 byte data: b'\x9a#\xe6\x00'…
Vincent Bénet
- 1,212
- 6
- 20
0
votes
1 answer
Am I wrong with these shiftings?
I have a 14 bits address with leading zeros and I want to divide it into page number and offset. I was trying to solve it with shifting the address but my offset is getting wrong value, however the page number shows up correctly. Can you point where…
Qaimaq
- 117
- 7