audio: output human-readable channel layouts too

This gets you the "logical" channel layout, instead of the exact thing
we're sending to the AO. (Tired of the cryptic shit ALSA gives me.)

4 files changed, 30 insertions, 10 deletions

diff --git a/audio/audio.c b/audio/audio.c
index a61e8c458c..c4ffc233a1 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -93,9 +93,13 @@ bool mp_audio_config_valid(const struct mp_audio *mpa)
 
 char *mp_audio_config_to_str_buf(char *buf, size_t buf_sz, struct mp_audio *mpa)
 {
+    char ch[128];
+    mp_chmap_to_str_buf(ch, sizeof(ch), &mpa->channels);
+    char *hr_ch = mp_chmap_to_str_hr(&mpa->channels);
+    if (strcmp(hr_ch, ch) != 0)
+        mp_snprintf_cat(ch, sizeof(ch), " (%s)", hr_ch);
     snprintf(buf, buf_sz, "%dHz %s %dch %s", mpa->rate,
-             mp_chmap_to_str(&mpa->channels), mpa->channels.num,
-             af_fmt_to_str(mpa->format));
+             ch, mpa->channels.num, af_fmt_to_str(mpa->format));
     return buf;
 }
 
diff --git a/audio/chmap.c b/audio/chmap.c
index 3bc2d2b15a..82f748b1cd 100644
--- a/audio/chmap.c
+++ b/audio/chmap.c
@@ -508,6 +508,25 @@ bool mp_chmap_from_str(struct mp_chmap *dst, bstr src)
     return true;
 }
 
+// Output a human readable "canonical" channel map string. Converting this from
+// a string back to a channel map can yield a different map, but the string
+// looks nicer. E.g. "fc-fl-fr-na" becomes "3.0".
+char *mp_chmap_to_str_hr_buf(char *buf, size_t buf_size, const struct mp_chmap *src)
+{
+    struct mp_chmap map = *src;
+    mp_chmap_remove_na(&map);
+    for (int n = 0; std_layout_names[n][0]; n++) {
+        struct mp_chmap s;
+        if (mp_chmap_from_str(&s, bstr0(std_layout_names[n][0])) &&
+            mp_chmap_equals_reordered(&s, &map))
+        {
+            map = s;
+            break;
+        }
+    }
+    return mp_chmap_to_str_buf(buf, buf_size, &map);
+}
+
 void mp_chmap_print_help(struct mp_log *log)
 {
     mp_info(log, "Speakers:\n");
diff --git a/audio/chmap.h b/audio/chmap.h
index ba1072547b..b27ec3bda8 100644
--- a/audio/chmap.h
+++ b/audio/chmap.h
@@ -128,6 +128,9 @@ int mp_chmap_diffn(const struct mp_chmap *a, const struct mp_chmap *b);
 char *mp_chmap_to_str_buf(char *buf, size_t buf_size, const struct mp_chmap *src);
 #define mp_chmap_to_str(m) mp_chmap_to_str_buf((char[64]){0}, 64, (m))
 
+char *mp_chmap_to_str_hr_buf(char *buf, size_t buf_size, const struct mp_chmap *src);
+#define mp_chmap_to_str_hr(m) mp_chmap_to_str_hr_buf((char[128]){0}, 128, (m))
+
 bool mp_chmap_from_str(struct mp_chmap *dst, bstr src);
 
 struct mp_log;
diff --git a/audio/out/ao.c b/audio/out/ao.c
index 4b9b2f9bec..c1333ab584 100644
--- a/audio/out/ao.c
+++ b/audio/out/ao.c
@@ -414,20 +414,14 @@ bool ao_chmap_sel_adjust(struct ao *ao, const struct mp_chmap_sel *s,
     if (mp_msg_test(ao->log, MSGL_DEBUG)) {
         for (int i = 0; i < s->num_chmaps; i++) {
             struct mp_chmap c = s->chmaps[i];
-            struct mp_chmap cr = c;
-            mp_chmap_reorder_norm(&cr);
-            mp_chmap_remove_na(&cr);
             MP_DBG(ao, "chmap_sel #%d: %s (%s)\n", i, mp_chmap_to_str(&c),
-                   mp_chmap_to_str(&cr));
+                   mp_chmap_to_str_hr(&c));
         }
     }
     bool r = mp_chmap_sel_adjust(s, map);
     if (r) {
-        struct mp_chmap mapr = *map;
-        mp_chmap_reorder_norm(&mapr);
-        mp_chmap_remove_na(&mapr);
         MP_DBG(ao, "result: %s (%s)\n", mp_chmap_to_str(map),
-               mp_chmap_to_str(&mapr));
+               mp_chmap_to_str_hr(map));
     }
     return r;
 }