topla -- creation of playlists for Motorola SLVR L7e phone

  Making of playlists with MOTOSLVR L7e [1] playlist editor is quite
  tedious. The results are binary .pla files stored in the file system
  of phone's memory card.

  `topla.py' creates binary playlists from the addresses of long file
  names (LFN) in FAT16 file system.

Playlist Format

       0    1    2    3    4    5    6    7
    +----+----+----+----+----+----+----+----+
    |  0 |  N |  0 |  1 |  0 |  0 |  0 |  0 |  <-- header
    +----+----+----+----+----+----+----+----+
    |  1 |0x40|sOff|         Segment        |  <-- entry #1
    +----+----+----+----+----+----+----+----+
    |  1 |0x40|sOff|         Segment        |  <-- entry #2
    +----+----+----+----+----+----+----+----+
    ...                                             ...
    +----+----+----+----+----+----+----+----+
    |  1 |0x40|sOff|         Segment        |  <-- entry #N
    +----+----+----+----+----+----+----+----+

  Header: 8 bytes

    Encodes the number of entries.

    N (1 byte) -- the number of audio files (entries).

  Entry: 8 bytes

    Encodes location of the earliest LFN [2] directory entry (dentry)
    that corresponds to a given audio file.

    Segment (4 bytes) -- zero-based number of segment;
    sOff (1 byte) -- offset from the beginning of segment.

Usage

  `topla.py' reads hex addresses of FAT16 LFN dentries from stdin and
  writes playlist data to stdout. `fat16dir' program [3] can be used
  to obtain the input addresses. (Another method is looking for
  necessary dentries in the file system's hex dump, but it is hardly
  better then using phone's playlist editor.)

Examples

    $ fat16dir.py /dev/sdb1 mobile/audio | grep mp3\$
    ----a +0004c100 shkatulka.mp3
    ----a +0004bfc0 the-it-crowd.mp3
    ----a +0004c0a0 the_passenger.mp3
    $ echo -e '0004c100\n0004bfc0\n0004c0a0' | topla.py | hexdump -C
    00000000  00 03 00 01 00 00 00 00  01 40 00 08 00 00 02 60  |.........@.....`|
    00000010  01 40 00 0e 00 00 02 5f  01 40 00 05 00 00 02 60  |.@....._.@.....`|
    00000020

    $ mount /mnt/winstick
    $ fat16dir/fat16dir.py /dev/sdb1 d/David\ Bowie.1977.Low | \
      cut -d' ' -f2 | topla/topla.py >/mnt/winstick/d/David\ Bowie_Low.pla
    $ umount /mnt/winstick

Credits

  Valery V. Vorotyntsev <valery.vv@gmail.com> -- hacked .pla format,
  wrote `topla.py'

  Alexander Gattin <alexander.gattin@gmail.com> -- wrote original
  version of `fat16dir.py'

References

 [1] http://www.motorola.com/motoinfo/product/details.jsp?globalObjectId=172
 [2] http://en.wikipedia.org/wiki/File_Allocation_Table#Long_file_names_2
 [3] http://github.com/vvv/fat16dir