Administrator@saint-desktop /cygdrive/c/Cygwin/Sources/rockbox/tools
$ ./convttf
Usage: convttf [options] [input-files]
       convttf [options] [-o output-file] [single-input-file]

       Default output-file : 'input-files name removed extension'_'font-size'_['
depth'].fnt.
                              When '-ta' or '-tc' is specified in command line,
                                default output-file is
                             'internal postscript-name of input-file'_'font-size
'_['depth'].fnt.
Options:
    -s N   Start output at character encodings >= N
    -l N   Limit output to character encodings <= N
    -p N   Font size N in pixel (default N=15)
    -c N   Character separation in pixel.Insert space between lines.
    -x     Trim glyphs horizontally of nearly empty space
              (to improve spacing on V's W's, etc.)
    -X N   Horizontal stretch (N percent)
    -TA N  Trim vertical ascent  (N percent)
    -TD N  Trim vertical descent (N percent)
    -Ta N  Trim vertical ascent  (N pixels)
    -Td N  Trim vertical descent (N pixels)
    -r N   Row separation in pixel.Insert space between characters
    -d     Debug: print converted glyph images
    -tt    Display the True Type Collection tables available in the font
    -t N   Index of true type collection. It must be start from 0.(default N=0).

    -ta    Convert all fonts in ttc
           "-o output-file" specified is ignored when "-ta" is specified.