Re: Decompress a zlib'd string in PHP

[Graham Anderson <grahama@xxxxxxxx>]

If I remove pack, I get the error:
gzuncompress(): data error

$uncompressed = gzuncompress($the_string);
echo $uncompressed;


in my hex editor, the movie header contains:
ftypqt   qt  PmoovHcmovdcomzlib4cmvd

From the Quicktime Docs, 'dcomzlib' is supposed to be the  
compression method for the below string:

fixúµRøo1ˆ](R•
uh·@A≤†∞ÅTïÜ©TQT1t1gÁŒäÌ;ùù+eÈ‘ˇѯòÏåå¸+·ŸÁ˚맆ƒK|ˆ{~˛figø°
...and so on


has anyone had experience with this ?
g

On Oct 26, 2005, at 12:15 PM, Jochem Maas wrote:

> Graham Anderson wrote:
>
> > Just to show I am not a total leech, I did consult the manual  
> > before  I posted the question :)
>
> ack.
>
>
> > The compressor in the file data says: dcomzlib
> > I tried the below with gzinflate and with gzuncompress.
> > Both give errors:
> >  gzinflate(): data error
> > gzuncompress(): data error
> > The below is the copy/pasted hex of the compressed movie header  
> > in  the Quicktime Movie File
> > FYI ,I did not compress the string myself...it is compressed   
> > automatically when a Quicktime movie is exported.
> > $compressed  =   
> > "DE789CB552BF6F133114F65D2852A50A7568E14041B2A00B120CB081549514860CA9 
> > 545  
> > 15431743167E7CE8AED3B9D9D2B65E9D4FF0484F8079810EC8C0C8CFC2BE1D9E7FB91 
> > A4A  
> > 008C44B7CF67B7EFEDE67BF0FA1B59F32CB4A849090654A61465F2FD21B762014BE72 
> > 234  
> > 0F6DFDA9CB3EC3F6D56F6FC92F520FEC1146402EB133371357B6DCD1AAD3D3B9BAD5E 
> > 37B  
> > 09F07CEDD61D46898FB4C68D39EF0B8EE6CB8262927B0C092FEE6EE080D613C4EA928 
> > ECB  
> > E4C4561D81B43F2FC914309822FD120CF05C32F218C0F1800E2215154303810BC935C 
> > 8D2  
> > 171944857204A2050B19D39F3C4EE5BD0151FB62143810C115C0319B15991F9EEC90C 
> > 042  
> > 71A3F27A64306EDD08A4C9F166CDC29B16141FCFA9336AF05CC2FB4D1B493B3EF082E 
> > D09  
> > ABB42659BB6BF16B372AF264CB1D23E318AB471FDA811EA5EF4A1523C1F6FC616ECBD 
> > F57  
> > B7B6D2CCEDAFCF007CCBB7146D9C2E3DDD38CA80E96B5ED098862F1616F4DA9B10CAF 
> > 292  
> > 299EBE2C36A234CFE20D3D0E734323DFF3B99462223B4835567AF20DFE0FD8AF27DD2 
> > 956  
> > FC929F38A0188E0F3CD4A31C710CE96F4FBCCEB77ABACF41B7474FB5F75F8CDEB70BC 
> > A0C  
> > 3E302501B1F7EB668E55E818780B60CFDA55DC6FA4071490CCF14BADCB0BBCABF6AF3 
> > 36B  
> > A549BBD6D98EF78795DB7F21A1D1DE27D124F92229BAAFA5E273EE3EE477D5A2068DE 
> > 01A  
> > 10C9F7293E2112FD9912109C38785058E72314D64567266D17653809256F81BB139CB 
> > 55A 6EC7A3D17E4CC01FF027425F9B1";
> > $string = pack("H*", $compressed);
>
> ok I don't understand pack() very well at all, but why are you  
> using it
> here? as far as I can tell gzinflate()/gzuncompress() don't work on  
> binary
> strings. what happens is you don't use pack()?
>
>
> > $uncompressed = gzinflate($string);
> > //$uncompressed = gzuncompress($string);
> > echo $uncompressed;
> > ?>
> > On Oct 26, 2005, at 10:20 AM, Jochem Maas wrote:
> >
> > > Graham Anderson wrote:
> > >
> > >
> > > > How do you decompress a zlib'd string located in a file with  php ?
> > > > I need to dynamically write a password string into a movie  
> > > > file.....
> > > > It appears that in QuickTime movie API, all sprite variables/  
> > > > values  are zlib'd inside the movie file
> > > > So I need to:
> > > > find the string
> > > > decompress a zlib'd string inside a file.
> > > > change its value => password=new_password
> > > > recompress the new value
> > > > write the zlib'd string back to the file
> > > > I'm  sure if I can decompress the string, then it will not be  
> > > > too   hard to do the rest :)
> > >
> > > I'm sure if you spent 5 seconds searching the manual you would  
> > > find  this page:
> > > http://php.net/manual/en/function.gzuncompress.php
> > >
> > > and this one:
> > >
> > > http://php.net/manual/en/function.gzcompress.php
> > >
> > > (HINT: I typed http://php.net/zlib into the address bar to find  
> > > them)
> > >
> > >
> > > 'the rest' involves find your substring's beginning and ending   
> > > offset and then
> > > using those values to 'splice' the new substring (aka password)   
> > > into the file/stream,
> > > I can visualize how ot do it but have never actually needed to  
> > > do  something like
> > > that ... I would say the compress/decompress is the easier part   
> > > personally ...
> > > buy hey as long as you get it working :-)
> > >
> > >
> > >
> > >
> > > > many thanks
> > >
> > > back at ya, I learnt some stuff answering (hopefully) you  
> > > question ;-)
> > >
> > >
> > >
> > > > g

--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php