If we see the calculation of bandTable it is updated as
for( k = 0; k < 4; k++ )

bandTable[ (k + saoLeftClass) & 31 ] = k + 1

so the array bandTable will contains values either 0 or 1 or 2 or 3 or 4.

we are calculating the variable bandidx like below.
The variable bandIdx is set equal to bandTable[ recPicture[ xC + i, yC + j ] >> bandShift ].

so bandidx can take any value among 0 or 1 or 2 or 3 or 4.

but the offset value what we have to add to the deblocked picture output will get from SaoOffsetVal[ cIdx ][ rx ][ ry ][ bandIdx ] .

here bandidx will take value among 0 or 1 or 2 or 3 but not 4.

So please have a look in to the updation of bandtable.

Thanks.

Regards,
Chaitanya Reddy