diff --git a/audio/chmap_sel.c b/audio/chmap_sel.c
index 160f1ce5fa..8e591aea44 100644
--- a/audio/chmap_sel.c
+++ b/audio/chmap_sel.c
@@ -81,14 +81,21 @@ void mp_chmap_sel_add_alsa_def(struct mp_chmap_sel *s)
     }
 }
 
-#define ARRAY_LEN(x) (sizeof(x) / sizeof((x)[0]))
-
 // Add a channel map that should be allowed.
 void mp_chmap_sel_add_map(struct mp_chmap_sel *s, const struct mp_chmap *map)
 {
-    assert(s->num_chmaps < ARRAY_LEN(s->chmaps));
-    if (mp_chmap_is_valid(map))
-        s->chmaps[s->num_chmaps++] = *map;
+    if (!mp_chmap_is_valid(map))
+        return;
+    if (!s->chmaps)
+        s->chmaps = s->chmaps_storage;
+    if (s->num_chmaps == MP_ARRAY_SIZE(s->chmaps)) {
+        if (!s->tmp)
+            return;
+        s->chmaps = talloc_memdup(s->tmp, s->chmaps, sizeof(s->chmaps_storage));
+    }
+    if (s->chmaps != s->chmaps_storage)
+        MP_TARRAY_GROW(s->tmp, s->chmaps, s->num_chmaps);
+    s->chmaps[s->num_chmaps++] = *map;
 }
 
 // Allow all waveext formats in default order.
diff --git a/audio/chmap_sel.h b/audio/chmap_sel.h
index c9d75196a5..7758ca5d74 100644
--- a/audio/chmap_sel.h
+++ b/audio/chmap_sel.h
@@ -26,8 +26,12 @@ struct mp_chmap_sel {
     // should be considered opaque
     bool allow_any, allow_waveext;
     bool speakers[MP_SPEAKER_ID_COUNT];
-    struct mp_chmap chmaps[20];
+    struct mp_chmap *chmaps;
     int num_chmaps;
+
+    struct mp_chmap chmaps_storage[20];
+
+    void *tmp; // set to any talloc context to allow more chmaps entries
 };
 
 void mp_chmap_sel_add_any(struct mp_chmap_sel *s);
diff --git a/audio/out/ao_alsa.c b/audio/out/ao_alsa.c
index 86745c6e80..4e54f161fe 100644
--- a/audio/out/ao_alsa.c
+++ b/audio/out/ao_alsa.c
@@ -279,7 +279,7 @@ static int find_alsa_channel(int mp_channel)
 static bool query_chmaps(struct ao *ao, struct mp_chmap *chmap)
 {
     struct priv *p = ao->priv;
-    struct mp_chmap_sel chmap_sel = {0};
+    struct mp_chmap_sel chmap_sel = {.tmp = p};
 
     snd_pcm_chmap_query_t **maps = snd_pcm_query_chmaps(p->alsa);
     if (!maps)
diff --git a/audio/out/ao_coreaudio.c b/audio/out/ao_coreaudio.c
index 1e1ad8cb10..6498f3ecad 100644
--- a/audio/out/ao_coreaudio.c
+++ b/audio/out/ao_coreaudio.c
@@ -185,7 +185,7 @@ static bool init_chmap(struct ao *ao)
                        &layouts, &n_layouts);
     CHECK_CA_ERROR("could not get audio device prefered layouts");
 
-    struct mp_chmap_sel chmap_sel = {0};
+    struct mp_chmap_sel chmap_sel = {.tmp = p};
     for (int i = 0; i < n_layouts; i++) {
         struct mp_chmap chmap = {0};
         if (ca_layout_to_mp_chmap(ao, &layouts[i], &chmap))