Python how to read raw binary from a file? (audio/video/text)



4 Answers

to get the binary representation I think you will need to import binascii, then:

byte = f.read(1)
binary_string = bin(int(binascii.hexlify(byte), 16))[2:].zfill(8)

or, broken down:

import binascii


filePath = "mysong.mp3"
file = open(filePath, "rb")
with file:
    byte = file.read(1)
    hexadecimal = binascii.hexlify(byte)
    decimal = int(hexadecimal, 16)
    binary = bin(decimal)[2:].zfill(8)
    print("hex: %s, decimal: %s, binary: %s" % (hexadecimal, decimal, binary))

will output:

hex: 64, decimal: 100, binary: 01100100
Question

I want to read the raw binary of a file and put it into a string. Currently I am opening a file with the "rb" flag and printing the byte but it's coming up as ASCII characters (for text that is, for video and audio files it's giving symbols and gibberish). I'd like to get the raw 0's and 1's if possible. This needs to work for audio and video files as well so simply converting the ascii to binary isn't an option.

file = open(filePath, "rb")
with file:
    byte = file.read(1)
    print byte



It is not quite clear what the sequence of bits is meant to be. I think it would be most natural to start at byte 0 with bit 0, but it actually depends on what you want.

So here is some code to access the sequence of bits starting with bit 0 in byte 0:

def bits_from_char(c):
    i = ord(c)
    for dummy in range(8):
        yield i & 1
        i >>= 1

def bits_from_data(data):
    for c in data:
        for bit in bits_from_char(c):
            yield bit

for bit in bits_from_data(data):
    #  process bit

(Another note: you would not need data[:][0] in your code. Simply data[0] would do the trick, but without copying the whole string first.)




This generator yields bytes from a file, reading the file in chunks:

def bytes_from_file(filename, chunksize=8192):
    with open(filename, "rb") as f:
        while True:
            chunk = f.read(chunksize)
            if chunk:
                for b in chunk:
                    yield b
            else:
                break

# example:
for b in bytes_from_file('filename'):
    do_stuff_with(b)

See the Python documentation for information on iterators and generators.




Built-in only python

Here is a pure python method for simple strings, left here for posterity.

def string2bits(s=''):
    return [bin(ord(x))[2:].zfill(8) for x in s]

def bits2string(b=None):
    return ''.join([chr(int(x, 2)) for x in b])

s = 'Hello, World!'
b = string2bits(s)
s2 = bits2string(b)

print 'String:'
print s

print '\nList of Bits:'
for x in b:
    print x

print '\nString:'
print s2

String:
Hello, World!

List of Bits:
01001000
01100101
01101100
01101100
01101111
00101100
00100000
01010111
01101111
01110010
01101100
01100100
00100001

String:
Hello, World!



Convert binary to ASCII and vice versa

For ASCII characters in the range [ -~] on Python 2:

>>> import binascii
>>> bin(int(binascii.hexlify('hello'), 16))
'0b110100001100101011011000110110001101111'

In reverse:

>>> n = int('0b110100001100101011011000110110001101111', 2)
>>> binascii.unhexlify('%x' % n)
'hello'

In Python 3.2+:

>>> bin(int.from_bytes('hello'.encode(), 'big'))
'0b110100001100101011011000110110001101111'

In reverse:

>>> n = int('0b110100001100101011011000110110001101111', 2)
>>> n.to_bytes((n.bit_length() + 7) // 8, 'big').decode()
'hello'

To support all Unicode characters in Python 3:

def text_to_bits(text, encoding='utf-8', errors='surrogatepass'):
    bits = bin(int.from_bytes(text.encode(encoding, errors), 'big'))[2:]
    return bits.zfill(8 * ((len(bits) + 7) // 8))

def text_from_bits(bits, encoding='utf-8', errors='surrogatepass'):
    n = int(bits, 2)
    return n.to_bytes((n.bit_length() + 7) // 8, 'big').decode(encoding, errors) or '\0'

Here's single-source Python 2/3 compatible version:

import binascii

def text_to_bits(text, encoding='utf-8', errors='surrogatepass'):
    bits = bin(int(binascii.hexlify(text.encode(encoding, errors)), 16))[2:]
    return bits.zfill(8 * ((len(bits) + 7) // 8))

def text_from_bits(bits, encoding='utf-8', errors='surrogatepass'):
    n = int(bits, 2)
    return int2bytes(n).decode(encoding, errors)

def int2bytes(i):
    hex_string = '%x' % i
    n = len(hex_string)
    return binascii.unhexlify(hex_string.zfill(n + (n & 1)))

Example

>>> text_to_bits('hello')
'0110100001100101011011000110110001101111'
>>> text_from_bits('110100001100101011011000110110001101111') == u'hello'
True



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