+/**
+ * Convert region offsets to region sizes and truncate
+ * size to big_values.
+ */
+void ff_region_offset2size(GranuleDef *g){
+ int i, k, j=0;
+ g->region_size[2] = (576 / 2);
+ for(i=0;i<3;i++) {
+ k = FFMIN(g->region_size[i], g->big_values);
+ g->region_size[i] = k - j;
+ j = k;
+ }
+}
+
+void ff_init_short_region(MPADecodeContext *s, GranuleDef *g){
+ if (g->block_type == 2)
+ g->region_size[0] = (36 / 2);
+ else {
+ if (s->sample_rate_index <= 2)
+ g->region_size[0] = (36 / 2);
+ else if (s->sample_rate_index != 8)
+ g->region_size[0] = (54 / 2);
+ else
+ g->region_size[0] = (108 / 2);
+ }
+ g->region_size[1] = (576 / 2);
+}
+
+void ff_init_long_region(MPADecodeContext *s, GranuleDef *g, int ra1, int ra2){
+ int l;
+ g->region_size[0] =
+ band_index_long[s->sample_rate_index][ra1 + 1] >> 1;
+ /* should not overflow */
+ l = FFMIN(ra1 + ra2 + 2, 22);
+ g->region_size[1] =
+ band_index_long[s->sample_rate_index][l] >> 1;
+}
+
+void ff_compute_band_indexes(MPADecodeContext *s, GranuleDef *g){
+ if (g->block_type == 2) {
+ if (g->switch_point) {
+ /* if switched mode, we handle the 36 first samples as
+ long blocks. For 8000Hz, we handle the 48 first
+ exponents as long blocks (XXX: check this!) */
+ if (s->sample_rate_index <= 2)
+ g->long_end = 8;
+ else if (s->sample_rate_index != 8)
+ g->long_end = 6;
+ else
+ g->long_end = 4; /* 8000 Hz */
+
+ g->short_start = 2 + (s->sample_rate_index != 8);
+ } else {
+ g->long_end = 0;
+ g->short_start = 0;
+ }
+ } else {
+ g->short_start = 13;
+ g->long_end = 22;
+ }
+}
+