Apparently pdf417lib comes in 3 flavors: C, C# and Java. You should technically be able to interface the former from Perl. The ReadMe.txt says:

The example is provided for Windows and was compiled using Visual C++ 6.0. The code can, however, be used with any ANSI C compiler. The only assumption is that an int is at least 32 bit long.

Compile (on Win32) with gcc (mingw):

C:\download\pdf417lib\pdf417lib-c-0.91>gcc --version
gcc (GCC) 3.4.5 (mingw special)

C:\download\pdf417lib\pdf417lib-c-0.91>gcc -o pdf417 pdf417.c pdf417li
+b.c

C:\download\pdf417lib\pdf417lib-c-0.91>pdf417 hello.ps "hello world"
Thello world
[download]

The generated "hello.ps" postscript file:

/Times findfont
12 scalefont setfont
100 80 moveto
(A PDF417 example.)show
stroke
100 100 translate
43 22.5 scale
86 15 1 [86 0 0 -15 0 15]{<
00AB8561C571E2A3F0175B
00AB857BCD1BE05630175B
00AB9507C6A06AF0F0175B
00AB82815BE4E50830175B
00AB947DC3EB628E70175B
00AB828F5DF4214130175B
00AB9630C6FA2B11F0175B
00AB8168D82C6A0630175B
00ABAC83D82320B170175B
00ABAE23CA106B9CF0175B
00AB963DD828E2C670175B
00AB9760D9CC205CD0175B
00ABAFAFC31D2BCF30175B
00AB85DEC29E6176F0175B
00AB85E14F852BF610175B
>}image
showpage
[download]

A simple makefile:

$ cat makefile
CC = gcc -O
pdf417 : pdf417.c pdf417lib.c pdf417lib.h
        $(CC) -o pdf417 pdf417.c pdf417lib.c pdf417lib.h -lm
[download]

Compile and run on Linux i386 (gcc version 3.4.6):

$ make
gcc -O -o pdf417 pdf417.c pdf417lib.c pdf417lib.h -lm
Compile on Linux i386:
$ ./pdf417 hello.ps "hello world"
Thello world
[download]

Converted with ps2pdf is shows the barcode in the lower left corner.

Update Tue Feb 19 12:26:16 CET 2008: Added sample code.
Update Wed Feb 20 08:22:01 CET 2008: Added Linux makefile.