Olle Bergkvist
Updated: 2007-03-30
www.olle.tk

Youre free to distribute this information, or change it. 

Read with the font Courier New to see the tables ok. 

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||       Specification of the PLX format       ||
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This file describes the .PLX format, used for "playlists" of pictures. 

It is intended for iriver's Portable Media Player 3rd and 4th generations, 
which includes iriver E10 and U10. 

   iRiver 4th generation (pmp_iriverplus3): 
   iRiver E10 UMS 

   iRiver 3rd generation (pmp_iriverplus2): 
   iRiver H10Jr. UMS 
   iRiver U10 UMS 

I can NOT guarantee that this will work for you, or even that this will not damage your computer or iriver player. 
It works for me, and SHOULD work for you too, but i cant be responsible if not. 

###########################
=== How to use pictures ===

To access a picture inside your E10 and use it as wallpaper, you need three files. 

1. The file actually used by E10. 
   It must be a JPEG picture and have a certain width and height. These values vary with type of DAP. 
   For E10: 128 pixels high and 128 pixles wide. 
   For U10: 240 pixles high and 320 pixels wide. 
   For H10Jr: Unknown. 
   It must be in a subfolder to "(path-to-E10)\System\Pictures". Assume the file name is:
   "(path-to-E10)\System\Pictures\myphotos\PICT001.JFU"

2. A thumbnail. 
   It must be a JPEG picture and have a certain width and height. These values vary with type of DAP. 
   For E10: 28 pixels high and 28 pixles wide. 
   For U10: 75 pixles high and 100 pixels wide. 
   For H10Jr: Unknown. 
   In this example the file name must be "(path-to-E10)\System\Pictures\myphotos\PICT001.JTH"

3. The PLX file itself. It must be in your Playlists directory. 

4. The file in the Pictures folder is NOT neccessary. But its often used because it provides a simple way to browse the 
   pictures stored on the DAP, and adding new pictures. 
   In this example this JPEG file should be located at:
   "(path-to-E10)\Pictures\myphotos\PICT001.JPG"


####################
=== The PLX file ===

The PLX files consists of a header and a number of entries. 
One entry for each picture to be displayed. 

Offset Length (bytes)     Data      (numbers are in hex)
------------------------------------------------------------
0             1           Number of entries (see above)
1             3           Zeros
4             x           Entry number one
4+x           y           Entry number two
4+x+y         z           Entry number three

And then the file ends. 


==Within each entry:==

Offset Length (bytes)     Data (numbers are in hex)
------------------------------------------------------------
0          1              Length of filename 
1          3              Zeros
4          1              Zero
5          1              First character of file name
6          1              Zero
7          1              Second character of file name
8          1              Zero
9          1              Third character of file name

       and so on...

Immediately after this, the second entry starts. And so on for the third and fourth entry...

The "Length of filename" is the number of BYTES, not characters, in file name. 
Multiply number-of-characters with 2 to get number of bytes. 

####################################
===How the file names are written===

The file names consists of a path like this:

Photo\leaf.jpg

When the DAP sees this file path, it adds the pictures directory. So it will look like this:

System\Pictures\Photo\leaf.jpg

Then, the DAP removes the file extension, if there is any. 

System\Pictures\Photo\leaf

Then the DAP adds the new file extensions ".jfu" and ".jth" to the file name. So to sum up, "Photo\leaf.jpg" will be decoded by the DAP to:

System\Pictures\Photo\leaf.jfu

and 

System\Pictures\Photo\leaf.jth

and the DAP will look for that JFU and that JTH. 

######################
That's it! Simple IMO. 

EOF (end of file)