I just tried to compile package libdv-0.104-4 with a prerelease of the
GNU C compiler version 4.1. It said

1.

encode.c:1811: warning: operation on "i" may be undefined

The source code is

                for (i = 0;
                        i < (DV_WIDTH * (dv_enc->isPAL ? DV_PAL_HEIGHT : DV_NTSC_HEIGHT));
                        dv_enc->img_y[i] = CLAMP(dv_enc->img_y[i++], -224, 214) );

I agree with the compiler - this code seems to be undefined.
Suggest new code

                for (i = 0;
                        i < (DV_WIDTH * (dv_enc->isPAL ? DV_PAL_HEIGHT : DV_NTSC_HEIGHT));
                        (dv_enc->img_y[ i] = CLAMP( dv_enc->img_y[i], -224, 214)), ++i );

BTW, the email address of the author is broken [ omega@cse.ogi.edu ]