1 files changed, 24 insertions, 16 deletions

diff --git a/audio/chmap.c b/audio/chmap.c
index 61df408e02..fcdb95edb3 100644
--- a/audio/chmap.c
+++ b/audio/chmap.c
@@ -100,6 +100,17 @@ static const struct mp_chmap default_layouts[MP_NUM_CHANNELS + 1] = {
     MP_CHMAP8(FL, FR, FC, LFE, BL, BR, SL, SR), // 7.1
 };
 
+// The channel order was lavc/waveex, but differs from lavc for 5, 6 and 8
+// channels. 3 and 7 channels were likely undefined (no ALSA support).
+static const char *mplayer_layouts[MP_NUM_CHANNELS + 1] = {
+    [1] = "mono",
+    [2] = "stereo",
+    [4] = "4.0",
+    [5] = "5.0(alsa)",
+    [6] = "5.1(alsa)",
+    [8] = "7.1(alsa)",
+};
+
 // Returns true if speakers are mapped uniquely, and there's at least 1 channel.
 bool mp_chmap_is_valid(const struct mp_chmap *src)
 {
@@ -192,6 +203,19 @@ void mp_chmap_from_channels(struct mp_chmap *dst, int num_channels)
     }
 }
 
+// Try to do what mplayer/mplayer2/mpv did before channel layouts were
+// introduced, i.e. get the old default channel order.
+void mp_chmap_from_channels_alsa(struct mp_chmap *dst, int num_channels)
+{
+    if (num_channels < 0 || num_channels > MP_NUM_CHANNELS) {
+        *dst = (struct mp_chmap) {0};
+    } else {
+        mp_chmap_from_str(dst, bstr0(mplayer_layouts[num_channels]));
+        if (!dst->num)
+            mp_chmap_from_channels(dst, num_channels);
+    }
+}
+
 // Set *dst to an unknown layout for the given numbers of channels.
 // If the number of channels is invalid, an invalid map is set, and
 // mp_chmap_is_valid(dst) will return false.
@@ -314,22 +338,6 @@ void mp_chmap_reorder_to_lavc(struct mp_chmap *map)
     mp_chmap_from_lavc(map, mask);
 }
 
-// Try to do what mplayer/mplayer2/mpv did before channel layouts were
-// introduced, i.e. get the old default channel order.
-void mp_chmap_reorder_to_alsa(struct mp_chmap *map)
-{
-    // The channel order was lavc/waveex, but differs from lavc for 5, 6 and 8
-    // channels. 3 and 7 channels were likely undefined (no ALSA support).
-    mp_chmap_from_channels(map, map->num);
-    if (map->num == 5) {
-        mp_chmap_from_str(map, bstr0("5.0(alsa)"));
-    } else if (map->num == 6) {
-        mp_chmap_from_str(map, bstr0("5.1(alsa)"));
-    } else if (map->num == 8) {
-        mp_chmap_from_str(map, bstr0("7.1(alsa)"));
-    }
-}
-
 // Get reordering array for from->to reordering. from->to must have the same set
 // of speakers (i.e. same number and speaker IDs, just different order). Then,
 // for each speaker n, dst[n] will be set such that: