+
+static pa_bool_t on_left(pa_channel_position_t p) {
+
+ return
+ p == PA_CHANNEL_POSITION_FRONT_LEFT ||
+ p == PA_CHANNEL_POSITION_REAR_LEFT ||
+ p == PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER ||
+ p == PA_CHANNEL_POSITION_SIDE_LEFT ||
+ p == PA_CHANNEL_POSITION_TOP_FRONT_LEFT ||
+ p == PA_CHANNEL_POSITION_TOP_REAR_LEFT;
+}
+
+static pa_bool_t on_right(pa_channel_position_t p) {
+
+ return
+ p == PA_CHANNEL_POSITION_FRONT_RIGHT ||
+ p == PA_CHANNEL_POSITION_REAR_RIGHT ||
+ p == PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER ||
+ p == PA_CHANNEL_POSITION_SIDE_RIGHT ||
+ p == PA_CHANNEL_POSITION_TOP_FRONT_RIGHT ||
+ p == PA_CHANNEL_POSITION_TOP_REAR_RIGHT;
+}
+
+static pa_bool_t on_center(pa_channel_position_t p) {
+
+ return
+ p == PA_CHANNEL_POSITION_FRONT_CENTER ||
+ p == PA_CHANNEL_POSITION_REAR_CENTER ||
+ p == PA_CHANNEL_POSITION_TOP_CENTER ||
+ p == PA_CHANNEL_POSITION_TOP_FRONT_CENTER ||
+ p == PA_CHANNEL_POSITION_TOP_REAR_CENTER;
+}
+
+static pa_bool_t on_lfe(pa_channel_position_t p) {
+
+ return
+ p == PA_CHANNEL_POSITION_LFE;
+}
+
+static pa_bool_t on_front(pa_channel_position_t p) {
+
+ return
+ p == PA_CHANNEL_POSITION_FRONT_LEFT ||
+ p == PA_CHANNEL_POSITION_FRONT_RIGHT ||
+ p == PA_CHANNEL_POSITION_FRONT_CENTER ||
+ p == PA_CHANNEL_POSITION_FRONT_LEFT_OF_CENTER ||
+ p == PA_CHANNEL_POSITION_FRONT_RIGHT_OF_CENTER ||
+ p == PA_CHANNEL_POSITION_TOP_FRONT_LEFT ||
+ p == PA_CHANNEL_POSITION_TOP_FRONT_RIGHT ||
+ p == PA_CHANNEL_POSITION_TOP_FRONT_CENTER;
+}
+
+static pa_bool_t on_rear(pa_channel_position_t p) {
+
+ return
+ p == PA_CHANNEL_POSITION_REAR_LEFT ||
+ p == PA_CHANNEL_POSITION_REAR_RIGHT ||
+ p == PA_CHANNEL_POSITION_REAR_CENTER ||
+ p == PA_CHANNEL_POSITION_TOP_REAR_LEFT ||
+ p == PA_CHANNEL_POSITION_TOP_REAR_RIGHT ||
+ p == PA_CHANNEL_POSITION_TOP_REAR_CENTER;
+}
+
+pa_cvolume *pa_cvolume_remap(pa_cvolume *v, const pa_channel_map *from, const pa_channel_map *to) {
+ int a, b;
+ pa_cvolume result;
+
+ pa_assert(v);
+ pa_assert(from);
+ pa_assert(to);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), NULL);
+ pa_return_val_if_fail(pa_channel_map_valid(from), NULL);
+ pa_return_val_if_fail(pa_channel_map_valid(to), NULL);
+ pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, from), NULL);
+
+ if (pa_channel_map_equal(from, to))
+ return v;
+
+ result.channels = to->channels;
+
+ for (b = 0; b < to->channels; b++) {
+ pa_volume_t k = 0;
+ int n = 0;
+
+ for (a = 0; a < from->channels; a++)
+ if (from->map[a] == to->map[b]) {
+ k += v->values[a];
+ n ++;
+ }
+
+ if (n <= 0) {
+ for (a = 0; a < from->channels; a++)
+ if ((on_left(from->map[a]) && on_left(to->map[b])) ||
+ (on_right(from->map[a]) && on_right(to->map[b])) ||
+ (on_center(from->map[a]) && on_center(to->map[b])) ||
+ (on_lfe(from->map[a]) && on_lfe(to->map[b]))) {
+
+ k += v->values[a];
+ n ++;
+ }
+ }
+
+ if (n <= 0)
+ k = pa_cvolume_avg(v);
+ else
+ k /= n;
+
+ result.values[b] = k;
+ }
+
+ *v = result;
+ return v;
+}
+
+int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) {
+
+ pa_assert(v);
+ pa_assert(ss);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), 0);
+ pa_return_val_if_fail(pa_sample_spec_valid(ss), 0);
+
+ return v->channels == ss->channels;
+}
+
+int pa_cvolume_compatible_with_channel_map(const pa_cvolume *v, const pa_channel_map *cm) {
+ pa_assert(v);
+ pa_assert(cm);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), 0);
+ pa_return_val_if_fail(pa_channel_map_valid(cm), 0);
+
+ return v->channels == cm->channels;
+}
+
+static void get_avg_lr(const pa_channel_map *map, const pa_cvolume *v, pa_volume_t *l, pa_volume_t *r) {
+ int c;
+ pa_volume_t left = 0, right = 0;
+ unsigned n_left = 0, n_right = 0;
+
+ pa_assert(v);
+ pa_assert(map);
+ pa_assert(map->channels == v->channels);
+ pa_assert(l);
+ pa_assert(r);
+
+ for (c = 0; c < map->channels; c++) {
+ if (on_left(map->map[c])) {
+ left += v->values[c];
+ n_left++;
+ } else if (on_right(map->map[c])) {
+ right += v->values[c];
+ n_right++;
+ }
+ }
+
+ if (n_left <= 0)
+ *l = PA_VOLUME_NORM;
+ else
+ *l = left / n_left;
+
+ if (n_right <= 0)
+ *r = PA_VOLUME_NORM;
+ else
+ *r = right / n_right;
+}
+
+float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) {
+ pa_volume_t left, right;
+
+ pa_assert(v);
+ pa_assert(map);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), 0.0f);
+ pa_return_val_if_fail(pa_channel_map_valid(map), 0.0f);
+ pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), 0.0f);
+
+ if (!pa_channel_map_can_balance(map))
+ return 0.0f;
+
+ get_avg_lr(map, v, &left, &right);
+
+ if (left == right)
+ return 0.0f;
+
+ /* 1.0, 0.0 => -1.0
+ 0.0, 1.0 => 1.0
+ 0.0, 0.0 => 0.0
+ 0.5, 0.5 => 0.0
+ 1.0, 0.5 => -0.5
+ 1.0, 0.25 => -0.75
+ 0.75, 0.25 => -0.66
+ 0.5, 0.25 => -0.5 */
+
+ if (left > right)
+ return -1.0f + ((float) right / (float) left);
+ else
+ return 1.0f - ((float) left / (float) right);
+}
+
+pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance) {
+ pa_volume_t left, nleft, right, nright, m;
+ unsigned c;
+
+ pa_assert(map);
+ pa_assert(v);
+ pa_assert(new_balance >= -1.0f);
+ pa_assert(new_balance <= 1.0f);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), NULL);
+ pa_return_val_if_fail(pa_channel_map_valid(map), NULL);
+ pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), NULL);
+
+ if (!pa_channel_map_can_balance(map))
+ return v;
+
+ get_avg_lr(map, v, &left, &right);
+
+ m = PA_MAX(left, right);
+
+ if (new_balance <= 0) {
+ nright = (new_balance + 1.0f) * m;
+ nleft = m;
+ } else {
+ nleft = (1.0f - new_balance) * m;
+ nright = m;
+ }
+
+ for (c = 0; c < map->channels; c++) {
+ if (on_left(map->map[c])) {
+ if (left == 0)
+ v->values[c] = nleft;
+ else
+ v->values[c] = (pa_volume_t) (((uint64_t) v->values[c] * (uint64_t) nleft) / (uint64_t) left);
+ } else if (on_right(map->map[c])) {
+ if (right == 0)
+ v->values[c] = nright;
+ else
+ v->values[c] = (pa_volume_t) (((uint64_t) v->values[c] * (uint64_t) nright) / (uint64_t) right);
+ }
+ }
+
+ return v;
+}
+
+pa_cvolume* pa_cvolume_scale(pa_cvolume *v, pa_volume_t max) {
+ unsigned c;
+ pa_volume_t t = 0;
+
+ pa_assert(v);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), NULL);
+ pa_return_val_if_fail(max != (pa_volume_t) -1, NULL);
+
+ for (c = 0; c < v->channels; c++)
+ if (v->values[c] > t)
+ t = v->values[c];
+
+ if (t <= 0)
+ return pa_cvolume_set(v, v->channels, max);
+
+ for (c = 0; c < v->channels; c++)
+ v->values[c] = (pa_volume_t) (((uint64_t) v->values[c] * (uint64_t) max) / (uint64_t) t);
+
+ return v;
+}
+
+static void get_avg_fr(const pa_channel_map *map, const pa_cvolume *v, pa_volume_t *f, pa_volume_t *r) {
+ int c;
+ pa_volume_t front = 0, rear = 0;
+ unsigned n_front = 0, n_rear = 0;
+
+ pa_assert(v);
+ pa_assert(map);
+ pa_assert(map->channels == v->channels);
+ pa_assert(f);
+ pa_assert(r);
+
+ for (c = 0; c < map->channels; c++) {
+ if (on_front(map->map[c])) {
+ front += v->values[c];
+ n_front++;
+ } else if (on_rear(map->map[c])) {
+ rear += v->values[c];
+ n_rear++;
+ }
+ }
+
+ if (n_front <= 0)
+ *f = PA_VOLUME_NORM;
+ else
+ *f = front / n_front;
+
+ if (n_rear <= 0)
+ *r = PA_VOLUME_NORM;
+ else
+ *r = rear / n_rear;
+}
+
+float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) {
+ pa_volume_t front, rear;
+
+ pa_assert(v);
+ pa_assert(map);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), 0.0f);
+ pa_return_val_if_fail(pa_channel_map_valid(map), 0.0f);
+ pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), 0.0f);
+
+ if (!pa_channel_map_can_fade(map))
+ return 0.0f;
+
+ get_avg_fr(map, v, &front, &rear);
+
+ if (front == rear)
+ return 0.0f;
+
+ if (rear > front)
+ return -1.0f + ((float) front / (float) rear);
+ else
+ return 1.0f - ((float) rear / (float) front);
+}
+
+pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float new_fade) {
+ pa_volume_t front, nfront, rear, nrear, m;
+ unsigned c;
+
+ pa_assert(map);
+ pa_assert(v);
+ pa_assert(new_fade >= -1.0f);
+ pa_assert(new_fade <= 1.0f);
+
+ pa_return_val_if_fail(pa_cvolume_valid(v), NULL);
+ pa_return_val_if_fail(pa_channel_map_valid(map), NULL);
+ pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(v, map), NULL);
+
+ if (!pa_channel_map_can_fade(map))
+ return v;
+
+ get_avg_fr(map, v, &front, &rear);
+
+ m = PA_MAX(front, rear);
+
+ if (new_fade <= 0) {
+ nfront = (new_fade + 1.0f) * m;
+ nrear = m;
+ } else {
+ nrear = (1.0f - new_fade) * m;
+ nfront = m;
+ }
+
+ for (c = 0; c < map->channels; c++) {
+ if (on_front(map->map[c])) {
+ if (front == 0)
+ v->values[c] = nfront;
+ else
+ v->values[c] = (pa_volume_t) (((uint64_t) v->values[c] * (uint64_t) nfront) / (uint64_t) front);
+ } else if (on_rear(map->map[c])) {
+ if (rear == 0)
+ v->values[c] = nrear;
+ else
+ v->values[c] = (pa_volume_t) (((uint64_t) v->values[c] * (uint64_t) nrear) / (uint64_t) rear);
+ }
+ }
+
+ return v;
+}