ud_compressunicode
comp_len = ud_compressunicode(length, 8, ptr, obuf);
static int32_t ud_compressunicode(int32_t, int32_t, uint16_t *, uint8_t *);
int32_t ud_compressunicode(int32_t, int32_t, uint16_t *, uint8_t *);