+int bam_prob_realn(bam1_t *b, const char *ref)
+{
+ int k, i, bw, x, y, yb, ye, xb, xe;
+ uint32_t *cigar = bam1_cigar(b);
+ bam1_core_t *c = &b->core;
+ ka_probpar_t conf = ka_probpar_def;
+ // find the start and end of the alignment
+ if (c->flag & BAM_FUNMAP) return -1;
+ x = c->pos, y = 0, yb = ye = xb = xe = -1;
+ for (k = 0; k < c->n_cigar; ++k) {
+ int op, l;
+ op = cigar[k]&0xf; l = cigar[k]>>4;
+ if (op == BAM_CMATCH) {
+ if (yb < 0) yb = y;
+ if (xb < 0) xb = x;
+ ye = y + l; xe = x + l;
+ x += l; y += l;
+ } else if (op == BAM_CSOFT_CLIP || op == BAM_CINS) y += l;
+ else if (op == BAM_CDEL) x += l;
+ else if (op == BAM_CREF_SKIP) return -1;
+ }
+ // set bandwidth and the start and the end
+ bw = 7;
+ if (abs((xe - xb) - (ye - yb)) > bw)
+ bw = abs((xe - xb) - (ye - yb)) + 3;
+ conf.bw = bw;
+ xb -= yb + bw/2; if (xb < 0) xb = 0;
+ xe += c->l_qseq - ye + bw/2;
+ if (xe - xb - c->l_qseq > bw)
+ xb += (xe - xb - c->l_qseq - bw) / 2, xe -= (xe - xb - c->l_qseq - bw) / 2;
+ { // glocal
+ uint8_t *s, *r, *q, *seq = bam1_seq(b), *qual = bam1_qual(b);
+ int *state;
+ s = calloc(c->l_qseq, 1);
+ for (i = 0; i < c->l_qseq; ++i) s[i] = bam_nt16_nt4_table[bam1_seqi(seq, i)];
+ r = calloc(xe - xb, 1);
+ for (i = xb; i < xe; ++i)
+ r[i-xb] = bam_nt16_nt4_table[bam_nt16_table[(int)ref[i]]];
+ state = calloc(c->l_qseq, sizeof(int));
+ q = calloc(c->l_qseq, 1);
+ ka_prob_glocal(r, xe-xb, s, c->l_qseq, qual, &conf, state, q);
+ for (k = 0, x = c->pos, y = 0; k < c->n_cigar; ++k) {
+ int op = cigar[k]&0xf, l = cigar[k]>>4;
+ if (op == BAM_CMATCH) {
+ for (i = y; i < y + l; ++i) {
+ if ((state[i]&3) != 0 || state[i]>>2 != x - xb + (i - y)) qual[i] = 0;
+ else qual[i] = qual[i] < q[i]? qual[i] : q[i];
+ }
+ x += l; y += l;
+ } else if (op == BAM_CSOFT_CLIP || op == BAM_CINS) y += l;
+ else if (op == BAM_CDEL) x += l;
+ }
+ free(s); free(r); free(q); free(state);
+ }
+ return 0;
+}
+