before applying balance/fade check it actually makes sense

diff --git a/src/pulse/volume.c b/src/pulse/volume.c
index ba2ee8fbbc5ec5934a63facb5a826a8d53a3dc30..01a28e83ac55dd8209e8689f3cf7eba02ed8d056 100644 (file)
--- a/src/pulse/volume.c
+++ b/src/pulse/volume.c
@@ -467,6 +467,9 @@ float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) {
     pa_assert(map);
     pa_assert(map->channels == v->channels);
 
+    if (!pa_channel_map_can_balance(map))
+        return 0.0f;
+
     get_avg_lr(map, v, &left, &right);
 
     if (left == right)
@@ -497,6 +500,9 @@ pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, flo
     pa_assert(new_balance >= -1.0f);
     pa_assert(new_balance <= 1.0f);
 
+    if (!pa_channel_map_can_balance(map))
+        return v;
+
     get_avg_lr(map, v, &left, &right);
 
     m = PA_MAX(left, right);
@@ -584,6 +590,9 @@ float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) {
     pa_assert(map);
     pa_assert(map->channels == v->channels);
 
+    if (!pa_channel_map_can_fade(map))
+        return 0.0f;
+
     get_avg_fr(map, v, &front, &rear);
 
     if (front == rear)
@@ -605,6 +614,9 @@ pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float
     pa_assert(new_fade >= -1.0f);
     pa_assert(new_fade <= 1.0f);
 
+    if (!pa_channel_map_can_fade(map))
+        return v;
+
     get_avg_fr(map, v, &front, &rear);
 
     m = PA_MAX(front, rear);

diff --git a/src/pulse/volume.h b/src/pulse/volume.h
index 8eef467f539019a9bcfb6653763d0c8cd80779ff..9ad3e9bf58ba56356bdcfe7b08048b90d02852a2 100644 (file)
--- a/src/pulse/volume.h
+++ b/src/pulse/volume.h
@@ -236,7 +236,9 @@ int pa_cvolume_compatible(const pa_cvolume *v, const pa_sample_spec *ss) PA_GCC_
 
 /** 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 */
+ * (left) to +1.0f (right). If no balance value is applicable to this
+ * channel map the return value will always be 0.0f. See
+ * pa_channel_map_can_balance(). \since 0.9.15 */
 float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE;
 
 /** Adjust the 'balance' value for the specified volume with the
@@ -245,22 +247,27 @@ float pa_cvolume_get_balance(const pa_cvolume *v, const pa_channel_map *map) PA_
  * operation might not be reversible! Also, after this call
  * pa_cvolume_get_balance() is not guaranteed to actually return the
  * requested balance value (e.g. when the input volume was zero anyway for
- * all channels) \since 0.9.15 */
+ * all channels). If no balance value is applicable to
+ * this channel map the volume will not be modified. See
+ * pa_channel_map_can_balance(). \since 0.9.15 */
 pa_cvolume* pa_cvolume_set_balance(pa_cvolume *v, const pa_channel_map *map, float new_balance);
 
 /** Calculate a 'fade' value (i.e. 'balance' between front and rear)
  * for the specified volume with the specified channel map. The return
- * value will range from -1.0f (rear) to +1.0f (left) \since
- * 0.9.15 */
+ * value will range from -1.0f (rear) to +1.0f (left). If no fade
+ * value is applicable to this channel map the return value will
+ * always be 0.0f. See pa_channel_map_can_fade(). \since 0.9.15 */
 float pa_cvolume_get_fade(const pa_cvolume *v, const pa_channel_map *map) PA_GCC_PURE;
 
 /** Adjust the 'fade' value (i.e. 'balance' between front and rear)
  * 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 reversible! Also,
- * after this call pa_cvolume_get_fade() is not guaranteed to
- * actually return the requested fade value (e.g. when the input volume
- * was zero anyway for all channels) \since 0.9.15 */
+ * after this call pa_cvolume_get_fade() is not guaranteed to actually
+ * return the requested fade value (e.g. when the input volume was
+ * zero anyway for all channels). If no fade value is applicable to
+ * this channel map the volume will not be modified. See
+ * pa_channel_map_can_fade(). \since 0.9.15 */
 pa_cvolume* pa_cvolume_set_fade(pa_cvolume *v, const pa_channel_map *map, float new_fade);
 
 /** Scale the passed pa_cvolume structure so that the maximum volume