在python中打开由ac程序编写为1和0的16位整数的二进制文件

Question

I have a bitstream file that is comprised of several lines. The c program executable that produces the file outputs the file as a series of "short int" which are actually 16 bit integers. When I open the file in notepad I get the following first few lines:

7E1755EB7909DAC8FF4117BDAA0E86EBD1A8
1C3D47DD6606D812E8862D347288C3A251EB
16D7D02AD908E0083C142C107AB916C55BE0

I need to be able to open this file in Python and convert it to 1s and 0s that represent the original "short int" or in other words an array of 1s and 0s. I think I might also have an issue with the "\\n" meaning new line when I read in the file.

I've tried the following code to see which method works best:

import struct

filePathC = "C:\\Working\\Vocoder Sims\\ofile.chan"

fileC = open(filePathC, "rb")

with fileC:

    byteC = fileC.read(8)

    binaryC1 = bin(int(byteC,16))
    binaryC2 = struct.unpack("h" * (len(byteC)/2),byteC)

    print binaryC1
    print binaryC2

The result for when I only read in the first 8 bytes is:

0b1111110000101110101010111101011
(17719, 14129, 13621, 16965)

The issue with the first result is that I should be getting 64 1s and 0s and the problem with the second is that it "tuple" instead of an array of 1s and 0s and I don't believe the integers are 16 bit based. They look more like 15 bit but I'm not sure.

Thanks in advance for any help.

Answer 1

Assuming you have binary data that just happens to decode as ascii hex, you could read the file into a python array . Its not much different than your second example of unpacking into a tuple except that its faster and has a lower memory footprint. Depending on what you want to do next, it would be reasonable to read into a numpy array instead.

import os
import array

#filePathC = "C:\\Working\\Vocoder Sims\\ofile.chan"
filePathC = "test.bin"

count = os.stat(filePathC).st_size / 2
with open(filePathC, 'rb') as fp:
    binaryC3 = array.array("h")
    binaryC3.fromfile(fp, count)

print binaryC3
print bin(binaryC3[0])

For your example file, this gave me

array('h', [17719, 14129, 13621, 16965, 14647, 14640, 16708, 14403, 17990, 12596, 14129, 17474, 16705, 17712, 13880, 16965, 12612, 14401, 12554, 13123, 13380, 17463, 13892, 12342, 17462, 12600, 17714, 14392, 12854, 13124, 14132, 14386, 17208, 16691, 13618, 17713, 2626, 13873, 14148, 12356, 16690, 14660, 14384, 12357, 14384, 17203, 13361, 17202, 12337, 16695, 14658, 13873, 13635, 16949, 12357])
0b100010100110111