return v % 2 ? m - (v + 1) / 2 : m + v / 2;
}
-static int decode_uniform(vp9_reader *r, int n) {
- int v;
- const int l = get_unsigned_bits(n);
- const int m = (1 << l) - n;
- if (!l)
- return 0;
-
- v = vp9_read_literal(r, l - 1);
+static int decode_uniform(vp9_reader *r) {
+ const int l = 8;
+ const int m = (1 << l) - 191;
+ const int v = vp9_read_literal(r, l - 1);
return v < m ? v : (v << 1) - m + vp9_read_bit(r);
}
}
}
-static int decode_term_subexp(vp9_reader *r, int k, int num_syms) {
- int i = 0, mk = 0, word;
- while (1) {
- const int b = i ? k + i - 1 : k;
- const int a = 1 << b;
- if (num_syms <= mk + 3 * a) {
- word = decode_uniform(r, num_syms - mk) + mk;
- break;
- } else {
- if (vp9_read_bit(r)) {
- i++;
- mk += a;
- } else {
- word = vp9_read_literal(r, b) + mk;
- break;
- }
- }
- }
- return word;
+static int decode_term_subexp(vp9_reader *r) {
+ if (!vp9_read_bit(r))
+ return vp9_read_literal(r, 4);
+ if (!vp9_read_bit(r))
+ return vp9_read_literal(r, 4) + 16;
+ if (!vp9_read_bit(r))
+ return vp9_read_literal(r, 5) + 32;
+ return decode_uniform(r) + 64;
}
void vp9_diff_update_prob(vp9_reader *r, vp9_prob* p) {
if (vp9_read(r, DIFF_UPDATE_PROB)) {
- const int delp = decode_term_subexp(r, SUBEXP_PARAM, 255);
+ const int delp = decode_term_subexp(r);
*p = (vp9_prob)inv_remap_prob(delp, *p);
}
}