bit parsing from file

[rewonka at gmail.com]

On máj. 29, 18:26, Mensanator <mensana... at aol.com> wrote:
> On May 29, 9:42�am, "rewo... at gmail.com" <rewo... at gmail.com> wrote:
>
>
>
>
>
> > Hello,
>
> > I'm tring to make a cutting script.
> > The problem is the following, i have a sample pattern, for
> > example :'11101110' (0xEE)
> > That is the sign of the data begining.
> > How can i cut a file if the byte stepping is not the same, for
> > example:
>
> > file=open('test.bin','rb')
> > data=file.read()
> > print binascii.hexlify(data) � � � � � �# BB9A (1011101110011010)
> > file.close()
>
> > so i need to cut the first two bit and start to writeout the bit
> > stream to another file
> > If somebody have an idea to do this, please share with me.
> > Thanx
>
> Cutting off the leading two bits isn't a problem,
> but once you write out the byte 11101110  you are
> left with 011010 which cannot be written as it's not
> a byte. How do you plan to handle that? Add two bits
> at the MSB (00011010) or two bits at the LSB (01101000)
> or discard the fractional byte?
>
> And do you always know what the bit offset is or
> do you have to search for the 11101110 starting
> pattern?
>
Thank's for the reply,
Yes, I have to search for the pattern, the bit offset not always the
same.
for another thing, it's ok if i can fill up with zero at the LSB or
discard that byte. (the last byte not important)

Rew