diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/map-file | 2 | ||||
| -rw-r--r-- | src/pulse/volume.c | 91 | ||||
| -rw-r--r-- | src/pulse/volume.h | 14 | ||||
| -rw-r--r-- | src/tests/voltest.c | 29 |
4 files changed, 136 insertions, 0 deletions
diff --git a/src/map-file b/src/map-file index 06ee4e17..9c9e1c7c 100644 --- a/src/map-file +++ b/src/map-file @@ -100,10 +100,12 @@ pa_cvolume_avg; pa_cvolume_channels_equal_to; pa_cvolume_compatible; pa_cvolume_equal; +pa_cvolume_get_balance; pa_cvolume_init; pa_cvolume_max; pa_cvolume_remap; pa_cvolume_set; +pa_cvolume_set_balance; pa_cvolume_snprint; pa_cvolume_valid; pa_ext_stream_restore_delete; diff --git a/src/pulse/volume.c b/src/pulse/volume.c index ace5c4d6..d4b1fd98 100644 --- a/src/pulse/volume.c +++ b/src/pulse/volume.c @@ -402,3 +402,94 @@ 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++; + } + } + + *l = left / n_left; + *r = right / n_right; +} + +float pa_cvolume_get_balance(const pa_channel_map *map, const pa_cvolume *v) { + 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(const pa_channel_map *map, pa_cvolume *v, 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; +} diff --git a/src/pulse/volume.h b/src/pulse/volume.h index 5815c906..08683ac7 100644 --- a/src/pulse/volume.h +++ b/src/pulse/volume.h @@ -233,6 +233,20 @@ pa_cvolume *pa_cvolume_remap(pa_cvolume *v, pa_channel_map *from, pa_channel_map * the specified sample spec. \since 0.9.13 */ int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) PA_GCC_PURE; +/** Calculate a 'balance' value for the specified volume with the + * specified channel map. The return value will range from -1.0f + * (left) to +1.0f (right) \since 0.9.15 */ +float pa_cvolume_get_balance(const pa_channel_map *map, const pa_cvolume *v) PA_GCC_PURE; + +/** Adjust the 'balance' value for the specified volume with the + * specified channel map. v will be modified in place and + * returned. The balance is a value between -1.0f and +1.0f. This + * operation might not be reversable! Also, after this call + * pa_cvolume_get_balance() is not guaranteed to actually return the + * requested balance (e.g. when the input volume was zero anyway for + * all channels)- \since 0.9.15 */ +pa_cvolume* pa_cvolume_set_balance(const pa_channel_map *map, pa_cvolume *v, float new_balance); + PA_C_DECL_END #endif diff --git a/src/tests/voltest.c b/src/tests/voltest.c index 5bfc97e0..879d86b9 100644 --- a/src/tests/voltest.c +++ b/src/tests/voltest.c @@ -6,6 +6,8 @@ int main(int argc, char *argv[]) { pa_volume_t v; pa_cvolume cv; + float b; + pa_channel_map map; for (v = PA_VOLUME_MUTED; v <= PA_VOLUME_NORM*2; v += 256) { @@ -28,5 +30,32 @@ int main(int argc, char *argv[]) { } + map.channels = cv.channels = 2; + map.map[0] = PA_CHANNEL_POSITION_LEFT; + map.map[1] = PA_CHANNEL_POSITION_RIGHT; + + for (cv.values[0] = PA_VOLUME_MUTED; cv.values[0] <= PA_VOLUME_NORM*2; cv.values[0] += 4096) + for (cv.values[1] = PA_VOLUME_MUTED; cv.values[1] <= PA_VOLUME_NORM*2; cv.values[1] += 4096) { + char s[PA_CVOLUME_SNPRINT_MAX]; + + printf("Volume: [%s]; balance: %2.1f\n", pa_cvolume_snprint(s, sizeof(s), &cv), pa_cvolume_get_balance(&map, &cv)); + } + + for (cv.values[0] = PA_VOLUME_MUTED+4096; cv.values[0] <= PA_VOLUME_NORM*2; cv.values[0] += 4096) + for (cv.values[1] = PA_VOLUME_MUTED; cv.values[1] <= PA_VOLUME_NORM*2; cv.values[1] += 4096) + for (b = -1.0f; b <= 1.0f; b += 0.2f) { + char s[PA_CVOLUME_SNPRINT_MAX]; + pa_cvolume r; + float k; + + printf("Before: volume: [%s]; balance: %2.1f\n", pa_cvolume_snprint(s, sizeof(s), &cv), pa_cvolume_get_balance(&map, &cv)); + + r = cv; + pa_cvolume_set_balance(&map, &r, b); + + k = pa_cvolume_get_balance(&map, &r); + printf("After: volume: [%s]; balance: %2.1f (intended: %2.1f) %s\n", pa_cvolume_snprint(s, sizeof(s), &r), k, b, k < b-.05 || k > b+.5 ? "MISMATCH" : ""); + } + return 0; } |