volume: introduce pa_cvolume_min() and pa_cvolume_min_mask()

3 files changed, 51 insertions, 2 deletions

diff --git a/src/map-file b/src/map-file
index 4f20c48f..d6122a4a 100644
--- a/src/map-file
+++ b/src/map-file
@@ -131,6 +131,8 @@ pa_cvolume_init;
 pa_cvolume_max;
 pa_cvolume_max_mask;
 pa_cvolume_merge;
+pa_cvolume_min;
+pa_cvolume_min_mask;
 pa_cvolume_remap;
 pa_cvolume_scale;
 pa_cvolume_scale_mask;
diff --git a/src/pulse/volume.c b/src/pulse/volume.c
index d7fb2477..e3535726 100644
--- a/src/pulse/volume.c
+++ b/src/pulse/volume.c
@@ -126,7 +126,7 @@ pa_volume_t pa_cvolume_avg_mask(const pa_cvolume *a, const pa_channel_map *cm, p
 }
 
 pa_volume_t pa_cvolume_max(const pa_cvolume *a) {
-    pa_volume_t m = 0;
+    pa_volume_t m = PA_VOLUME_MUTED;
     unsigned c;
 
     pa_assert(a);
@@ -139,8 +139,22 @@ pa_volume_t pa_cvolume_max(const pa_cvolume *a) {
     return m;
 }
 
+pa_volume_t pa_cvolume_min(const pa_cvolume *a) {
+    pa_volume_t m = (pa_volume_t) -1;
+    unsigned c;
+
+    pa_assert(a);
+    pa_return_val_if_fail(pa_cvolume_valid(a), PA_VOLUME_MUTED);
+
+    for (c = 0; c < a->channels; c++)
+        if (m == (pa_volume_t) -1 || a->values[c] < m)
+            m = a->values[c];
+
+    return m;
+}
+
 pa_volume_t pa_cvolume_max_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) {
-    pa_volume_t m = 0;
+    pa_volume_t m = PA_VOLUME_MUTED;
     unsigned c, n;
 
     pa_assert(a);
@@ -162,6 +176,29 @@ pa_volume_t pa_cvolume_max_mask(const pa_cvolume *a, const pa_channel_map *cm, p
     return m;
 }
 
+pa_volume_t pa_cvolume_min_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) {
+    pa_volume_t m = (pa_volume_t) -1;
+    unsigned c, n;
+
+    pa_assert(a);
+
+    if (!cm)
+        return pa_cvolume_min(a);
+
+    pa_return_val_if_fail(pa_cvolume_compatible_with_channel_map(a, cm), PA_VOLUME_MUTED);
+
+    for (c = n = 0; c < a->channels; c++) {
+
+        if (!(PA_CHANNEL_POSITION_MASK(cm->map[c]) & mask))
+            continue;
+
+        if (m == (pa_volume_t) -1 || a->values[c] < m)
+            m = a->values[c];
+    }
+
+    return m;
+}
+
 pa_volume_t pa_sw_volume_multiply(pa_volume_t a, pa_volume_t b) {
     return pa_sw_volume_from_linear(pa_sw_volume_to_linear(a) * pa_sw_volume_to_linear(b));
 }
diff --git a/src/pulse/volume.h b/src/pulse/volume.h
index 3881da2f..349ca49f 100644
--- a/src/pulse/volume.h
+++ b/src/pulse/volume.h
@@ -195,6 +195,16 @@ pa_volume_t pa_cvolume_max(const pa_cvolume *a) PA_GCC_PURE;
  * \since 0.9.16 */
 pa_volume_t pa_cvolume_max_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;
 
+/** Return the minimum volume of all channels. \since 0.9.16 */
+pa_volume_t pa_cvolume_min(const pa_cvolume *a) PA_GCC_PURE;
+
+/** Return the minimum volume of all channels that are included in the
+ * specified channel map with the specified channel position mask. If
+ * cm is NULL this call is identical to pa_cvolume_min(). If no
+ * channel is selected the returned value will be PA_VOLUME_MUTED.
+ * \since 0.9.16 */
+pa_volume_t pa_cvolume_min_mask(const pa_cvolume *a, const pa_channel_map *cm, pa_channel_position_mask_t mask) PA_GCC_PURE;
+
 /** Return TRUE when the passed cvolume structure is valid, FALSE otherwise */
 int pa_cvolume_valid(const pa_cvolume *v) PA_GCC_PURE;