export pa_channel_map_superset()

2 files changed, 22 insertions, 0 deletions

diff --git a/src/pulse/channelmap.c b/src/pulse/channelmap.c
index fd313bd3..26eae599 100644
--- a/src/pulse/channelmap.c
+++ b/src/pulse/channelmap.c
@@ -577,3 +577,22 @@ int pa_channel_map_compatible(const pa_channel_map *map, const pa_sample_spec *s
 
     return map->channels == ss->channels;
 }
+
+int pa_channel_map_superset(const pa_channel_map *a, const pa_channel_map *b) {
+    pa_bool_t in_a[PA_CHANNEL_POSITION_MAX];
+    unsigned i;
+
+    pa_assert(a);
+    pa_assert(b);
+
+    memset(in_a, 0, sizeof(in_a));
+
+    for (i = 0; i < a->channels; i++)
+        in_a[a->map[i]] = TRUE;
+
+    for (i = 0; i < b->channels; i++)
+        if (!in_a[b->map[i]])
+            return 0;
+
+    return 1;
+}
diff --git a/src/pulse/channelmap.h b/src/pulse/channelmap.h
index d7d19d79..a6c044f1 100644
--- a/src/pulse/channelmap.h
+++ b/src/pulse/channelmap.h
@@ -227,6 +227,9 @@ int pa_channel_map_valid(const pa_channel_map *map) PA_GCC_PURE;
  * the specified sample spec. \since 0.9.12 */
 int pa_channel_map_compatible(const pa_channel_map *map, const pa_sample_spec *ss) PA_GCC_PURE;
 
+/** Returns non-zero if every channel defined in b is also defined in a. \since 0.9.15 */
+int pa_channel_map_superset(const pa_channel_map *a, const pa_channel_map *b) PA_GCC_PURE;
+
 PA_C_DECL_END
 
 #endif