Any size limit when binding BLOB parameter using SQLT_LBI?

I called OCIBindByPos() to bind one BLOB parameter, and set value_sz to the actual size of some buffer in my application, indp and alenp to NULL, and dty to SQLT_LBI.It worked before I tried to set value_sz greater than 64K.
When value_sz is greater than 64K, looks like the length of buffer put into DB is random.

Is there such limit of size?

thanks in advance!

sword OCIBindByPos ( OCIStmt *stmtp,
OCIBind **bindpp,
OCIError *errhp,
ub4 position,
dvoid *valuep,
sb4 value_sz,
ub2 dty,
dvoid *indp,
ub2 *alenp,
ub2 *rcodep,
ub4 maxarr_len,
ub4 *curelep,
ub4 mode );