+static void sd_1d97_float(float *p, int i0, int i1)
+{
+ int i;
+
+ if (i1 == i0 + 1)
+ return;
+
+ extend97_float(p, i0, i1);
+ i0++; i1++;
+
+ for (i = i0/2 - 2; i < i1/2 + 1; i++)
+ p[2*i+1] -= 1.586134 * (p[2*i] + p[2*i+2]);
+ for (i = i0/2 - 1; i < i1/2 + 1; i++)
+ p[2*i] -= 0.052980 * (p[2*i-1] + p[2*i+1]);
+ for (i = i0/2 - 1; i < i1/2; i++)
+ p[2*i+1] += 0.882911 * (p[2*i] + p[2*i+2]);
+ for (i = i0/2; i < i1/2; i++)
+ p[2*i] += 0.443506 * (p[2*i-1] + p[2*i+1]);
+}
+
+static void dwt_encode97_float(DWTContext *s, float *t)
+{
+ int lev,
+ w = s->linelen[s->ndeclevels-1][0];
+ float *line = s->f_linebuf;
+ line += 5;
+
+ for (lev = s->ndeclevels-1; lev >= 0; lev--){
+ int lh = s->linelen[lev][0],
+ lv = s->linelen[lev][1],
+ mh = s->mod[lev][0],
+ mv = s->mod[lev][1],
+ lp;
+ float *l;
+
+ // HOR_SD
+ l = line + mh;
+ for (lp = 0; lp < lv; lp++){
+ int i, j = 0;
+
+ for (i = 0; i < lh; i++)
+ l[i] = t[w*lp + i];
+
+ sd_1d97_float(line, mh, mh + lh);
+
+ // copy back and deinterleave
+ for (i = mh; i < lh; i+=2, j++)
+ t[w*lp + j] = F_LFTG_X * l[i] / 2;
+ for (i = 1-mh; i < lh; i+=2, j++)
+ t[w*lp + j] = F_LFTG_K * l[i] / 2;
+ }
+
+ // VER_SD
+ l = line + mv;
+ for (lp = 0; lp < lh; lp++) {
+ int i, j = 0;
+
+ for (i = 0; i < lv; i++)
+ l[i] = t[w*i + lp];
+
+ sd_1d97_float(line, mv, mv + lv);
+
+ // copy back and deinterleave
+ for (i = mv; i < lv; i+=2, j++)
+ t[w*j + lp] = F_LFTG_X * l[i] / 2;
+ for (i = 1-mv; i < lv; i+=2, j++)
+ t[w*j + lp] = F_LFTG_K * l[i] / 2;
+ }
+ }
+}