convert hex to bytes?

blitzkrg · January 30, 2006

Need some help understanding hex conversions.

I have a binary file that i'm trying to read (and eventually write to)

i am using _hextostring to convert some of the *text* stuff and it's working fine.

i throw in some hex code and it spits out the ascii text string.. which is great

but when it comes to the numbers i'm having a problem

76AB4D0000000000 is hex code, it's supposed to be a filesize (audio file)

but i'm not sure how to convert it to mb/kb file size

AD000000 is hex code, it's supposed to be the "play time" of an audio file

thanks

JSThePatriot · January 30, 2006

That hex doesnt even return numbers. You sure that is the proper hex for what you are looking for?

JS

blitzkrg · January 30, 2006

That hex doesnt even return numbers. You sure that is the proper hex for what you are looking for?
JS

yeah i know, that's why i asked for help :lmao:

umm.. the file is a playlist file, it's a binary file.

when i look at it with hex editor, i can see the ascii text.

i found a blog that had the "breakdown" of the format

for example

the 1st (4 bytes) is an init sequence

the 2nd (2 bytes) is the track number

the 3rd (8 bytes) is the song name

the 4th (8 bytes) is the file size

none of that is accurate, just as an example of how it had it broke down

and when i followed the file i found when he said the <artist> was here, it was

the <song title> was here. it was

so like i said the ascii stuff all worked out fine.

its the numbers (file size, song legnth) all that jazz was just little boxes in my hex editor.

so i'm thinking i have convert from binary some how?

i'm just not sure what to do with them.

blitzkrg · January 30, 2006

Header

01 00 00 00 00 00 Init Sequence

00 00 00 00 Nr of Entries

For each Entry:

02 00 Init entry

00 00 00 00 Entrynumber /position

00 00 00 00 00 00 00 00 Filesize

00 00 00 00 Playtime

00 00 00 00 Size of title

? ? ? ? ? ? ? ? Title

00 00 00 00 Size of artist

? ? ? ? ? ? ? ? Artist

00 00 00 00 Size of album

? ? ? ? ? ? ? ? Album

00 00 00 00 Size of genre

? ? ? ? ? ? ? ? Genre

00 00 00 00 Size of absolute file path

? ? ? ? ? ? ? ? Absolute file path

00 Track nr

00 Closing byte

blitzkrg · January 30, 2006

that's how he broke down the file.

so from the start of the file

if i count allt he way down to "title"

it's in the right spot the ?'s just mean variable legnth because the title could be anything

so if i punch in the hex codes for "title" from my hex editor and i use _hextostring, it returns the title of the song..

and that's what it should do

but when i get to things like file size or playtime or size of artist.. all that jaz. it's just a bunch of boxes.

i assume _hextostring isnt going to work since the hex codes are for numbers?

i dunno.. numbers are ascii strings to..

soooo i'm confused :lmao:

edit: if it helps i've uploaded a sample playlist file.

rename it to <whatever>.spl

1.txt

Edited January 30, 2006 by blitzkrg

JSThePatriot · January 30, 2006

Its possible maybe that the HEX is encoded at that point for some weird reason. When I run the code and output the result to a message box, it shows just some odd characters (not numbers).

Hrm... I am not sure about your issue... is it possible that this file just doesnt have the time or something along those lines? Does this hold true on all the files you try?

I wish I could help more...

JS

blitzkrg · January 31, 2006

Its possible maybe that the HEX is encoded at that point for some weird reason. When I run the code and output the result to a message box, it shows just some odd characters (not numbers).
Hrm... I am not sure about your issue... is it possible that this file just doesnt have the time or something along those lines? Does this hold true on all the files you try?
I wish I could help more...
JS

I'm told it's little endian format?

but i'm not sure what to do with that info

Helge · January 31, 2006

Maybe you want to make it yourself, but you could anyway check out

LazyCat's UDFs http://www.autoitscript.com/fileman/users/Lazycat/udfs.html. Scroll down a bit and you'll see.

w0uter · January 31, 2006

endian is the way it is written

big endian: 00112233

litle endian: 33221100

both are 0x00112233

pff just saw the attached file. that aint really hard :lmao:

Edited January 31, 2006 by w0uter

JSThePatriot · January 31, 2006

Maybe the following links will help. I didnt have the time to read but the first part of them, and they both looked helpful.

Link 1

Link 2

Hope this helps,

JS

w0uter · January 31, 2006

small example:

$s_file = 'index.php'

$as_hex = StringRegExp(StringTrimLeft(String(BinaryString(Chr(0) & FileRead($s_file))), 4), '(..)*', 1)

$i_title = '0x' & $as_hex[0x1F] & $as_hex[0x1E] & $as_hex[0x1D] & $as_hex[0x1C]
$s_title = ''

for $i = 0 to $i_title-1
    $s_title &= Chr('0x' & $as_hex[0x20+$i])
Next

ConsoleWrite($s_title & @LF)

$i_artist = '0x' & $as_hex[0x23+$i_title]  & $as_hex[0x22+$i_title]  & $as_hex[0x21+$i_title]  & $as_hex[0x20+$i_title]
$s_artist = ''

for $i = 0 to $i_artist-1
    $s_artist &= Chr('0x' & $as_hex[0x24+$i_title+$i])
Next

ConsoleWrite($s_artist & @LF)

jaenster · January 31, 2006

why not hextostring , string to bits

Edited January 31, 2006 by jaenster

blitzkrg · January 31, 2006

string to bits? is that a funciton?

the 1st part of my file looks like this (i broke it down based on the above posted layout

010000000000<INIT SEQUENCE>13000000<NR. OF ENTRIES>0200<INIT ENTRY>01000000<ENTRY NUMBER>76AB4D0000000000<FILESIZE>AD000000<PLAYTIME>08000000<size of title>576F726420557021<title>04000000<size of artist>4B6F726E<artist>14000000<size of album>4772656174657374204869747320566F6C2E2031<album>09000000<size of genre>4861726420526F636B<genre>3C000000<size of absolute file path>5C4469736B5C4D79204D757369635C4B6F726E5C4772656174657374204869747320566F6C2E20315C30312D6B6F726E2

D776F72645F75702E6D7033<ABSOLUTE FILE PATH>01<TRACK NUMBER>00<CLOSING BYTE>

Note: the description is to the right of the numbers.

IF you use _hextostring and plug in the hex values for the text stuff, it will spit out everything correctly (i.e. artist, title, path) all that stuff works.

What doesnt work is Filesize, playtime, size of artist, etc...

I understand that it could be written in a little endian format BUT JSthepatriot raised a good point, are those values correct.

I didnt have the time to confirm last night. (i will do so tonight)

But i want to not only be able to read the information out of here, i want to be able to write back to it.

00 00 00 is going to equal = 0

correct? so no matter what format it's written in, it's still 0

so i dont understand how these numbers are valid in a LE encoding?

(filesize) 76AB4D0000000000

(playtime) AD000000

(size of album)14000000

Looking up LE i found(as all of you correctly indicated it would be):

"Little Endian" means that the low-order byte of the number is stored in memory at the lowest address, and the high-order byte at the highest address. (The little end comes first.) For example, a 4 byte LongInt

Byte3 Byte2 Byte1 Byte0

will be arranged in memory as follows:

Base Address+0 Byte0

Base Address+1 Byte1

Base Address+2 Byte2

Base Address+3 Byte3

so the quandry is how do i transform 76AB4D0000000000 into something meaningful?

Edited January 31, 2006 by blitzkrg

jaenster · January 31, 2006

All progaming langauges has a sting to bit :S ..

seandisanti · January 31, 2006

i think everyone and their mom has written number conversion scripts, could just use a hex2dec and a dec2bin. You could just write a script to change from hex to bin, but it was easier to just use both of these than to do that.

$hex = "FF"
msgbox(0,"Hex2Bin",Dec2Bin(Hex2Dec($hex)))
Func Dec2Bin($number)
    $result = ""
    $power = 7
    While $number > 0
        If BitAND(2 ^ $power, $number) Then
            $result = $result & "1"
            $number = $number - 2 ^ $power
        Else
            $result = $result & "0"
        EndIf
        $power = $power - 1
    WEnd
    While StringLen($result) < 8
        If StringLen($result) < 8 Then $result = $result & "0"
    WEnd
    Return String($result)
EndFunc  ;==>Dec2Bin
Func Hex2Dec($number)
    $result = 0
    For $x = 0 To StringLen($number)
        Switch StringMid($number, StringLen($number) - $x, 1)
        Case "A"
            $result = $result + 10 * 16^$x
        Case "B"
            $result = $result + 11 * 16^$x
        Case "C"
            $result = $result + 12 * 16^$x
        Case "D"
            $result = $result + 13 * 16^$x
        Case "E"
            $result = $result + 14 * 16^$x
        Case "F"
            $result = $result + 15 * 16^$x
        Case "x"
            ExitLoop
        Case Else
            $result = $result + Int(StringMid($number, StringLen($number) - $x, 1)) * 16^$x
        EndSwitch
    Next
    Return $result
EndFunc

convert hex to bytes?

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