diff options
Diffstat (limited to 'src/pulse/volume.c')
-rw-r--r-- | src/pulse/volume.c | 119 |
1 files changed, 118 insertions, 1 deletions
diff --git a/src/pulse/volume.c b/src/pulse/volume.c index ace5c4d6..3434cb18 100644 --- a/src/pulse/volume.c +++ b/src/pulse/volume.c @@ -341,7 +341,7 @@ static pa_bool_t on_lfe(pa_channel_position_t p) { p == PA_CHANNEL_POSITION_LFE; } -pa_cvolume *pa_cvolume_remap(pa_cvolume *v, pa_channel_map *from, pa_channel_map *to) { +pa_cvolume *pa_cvolume_remap(pa_cvolume *v, const pa_channel_map *from, const pa_channel_map *to) { int a, b; pa_cvolume result; @@ -402,3 +402,120 @@ int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) { return v->channels == ss->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_assert(map->channels == v->channels); + + 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->channels == v->channels); + pa_assert(map); + pa_assert(v); + pa_assert(new_balance >= -1.0f); + pa_assert(new_balance <= 1.0f); + + 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] = 0; + 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] = 0; + 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(c); + + 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; +} |