audio: define only a single NA speaker ID

Remove the requirement from mp_chmap that speaker entries must be
unique. Use this to get rid of all the redundant NA speaker IDs.

5 files changed, 16 insertions, 34 deletions

diff --git a/audio/chmap.c b/audio/chmap.c
index 7e62dab74a..a36a6d9bdf 100644
--- a/audio/chmap.c
+++ b/audio/chmap.c
@@ -50,6 +50,7 @@ static const char *const speaker_names[MP_SPEAKER_ID_COUNT][2] = {
     [MP_SPEAKER_ID_SDL]         = {"sdl",  "surround direct left"},
     [MP_SPEAKER_ID_SDR]         = {"sdr",  "surround direct right"},
     [MP_SPEAKER_ID_LFE2]        = {"lfe2", "low frequency 2"},
+    [MP_SPEAKER_ID_NA]          = {"na",   "not available"},
 };
 
 // Names taken from libavutil/channel_layout.c (Not accessible by API.)
@@ -127,7 +128,8 @@ bool mp_chmap_is_valid(const struct mp_chmap *src)
         int sp = src->speaker[n];
         if (sp >= MP_SPEAKER_ID_COUNT || mapped[sp])
             return false;
-        mapped[sp] = true;
+        if (sp != MP_SPEAKER_ID_NA)
+            mapped[sp] = true;
     }
     return src->num > 0;
 }
@@ -196,7 +198,7 @@ void mp_chmap_remove_na(struct mp_chmap *map)
     struct mp_chmap new = {0};
     for (int n = 0; n < map->num; n++) {
         int sp = map->speaker[n];
-        if (!(sp >= MP_SPEAKER_ID_NA0 && sp <= MP_SPEAKER_ID_NA_LAST))
+        if (sp != MP_SPEAKER_ID_NA)
             new.speaker[new.num++] = map->speaker[n];
     }
     *map = new;
@@ -206,15 +208,8 @@ void mp_chmap_remove_na(struct mp_chmap *map)
 void mp_chmap_fill_na(struct mp_chmap *map, int num)
 {
     assert(num <= MP_NUM_CHANNELS);
-    while (map->num < num) {
-        int sp = map->num ? map->speaker[map->num - 1] : -1;
-        if (sp >= MP_SPEAKER_ID_NA0 && sp < MP_SPEAKER_ID_NA_LAST) {
-            sp += 1;
-        } else {
-            sp = MP_SPEAKER_ID_NA0;
-        }
-        map->speaker[map->num++] = sp;
-    }
+    while (map->num < num)
+        map->speaker[map->num++] = MP_SPEAKER_ID_NA;
 }
 
 // Set *dst to a standard layout with the given number of channels.
@@ -306,7 +301,7 @@ uint64_t mp_chmap_to_lavc_unchecked(const struct mp_chmap *src)
         mp_chmap_from_channels(&t, t.num);
     uint64_t mask = 0;
     for (int n = 0; n < t.num; n++) {
-        if (t.speaker[n] < 64) // ignore MP_SPEAKER_ID_NA* etc.
+        if (t.speaker[n] < 64) // ignore MP_SPEAKER_ID_NA etc.
             mask |= 1ULL << t.speaker[n];
     }
     return mask;
@@ -440,12 +435,7 @@ char *mp_chmap_to_str_buf(char *buf, size_t buf_size, const struct mp_chmap *src
         const char *s = sp < MP_SPEAKER_ID_COUNT ? speaker_names[sp][0] : NULL;
         char sp_buf[10];
         if (!s) {
-            const char *prefix = "sp";
-            if (sp >= MP_SPEAKER_ID_NA0 && sp <= MP_SPEAKER_ID_NA_LAST) {
-                sp -= MP_SPEAKER_ID_NA0;
-                prefix = "na";
-            }
-            snprintf(sp_buf, sizeof(sp_buf), "%s%d", prefix, sp);
+            snprintf(sp_buf, sizeof(sp_buf), "sp%d", sp);
             s = sp_buf;
         }
         mp_snprintf_cat(buf, buf_size, "%s%s", n > 0 ? "-" : "", s);
diff --git a/audio/chmap.h b/audio/chmap.h
index 296b2a1712..d3ce5cdb21 100644
--- a/audio/chmap.h
+++ b/audio/chmap.h
@@ -62,9 +62,9 @@ enum mp_speaker_id {
     MP_SPEAKER_ID_UNKNOWN_LAST = MP_SPEAKER_ID_UNKNOWN0 + MP_NUM_CHANNELS - 1,
 
     // "Silent" channels. These are sometimes used to insert padding for
-    // unused channels.
-    MP_SPEAKER_ID_NA0,
-    MP_SPEAKER_ID_NA_LAST = MP_SPEAKER_ID_NA0 + MP_NUM_CHANNELS - 1,
+    // unused channels. Unlike other speaker types, multiple of these can
+    // occur in a single mp_chmap.
+    MP_SPEAKER_ID_NA,
 
     // Including the unassigned IDs in between. This is not a valid ID anymore,
     // but is still within uint8_t.
diff --git a/audio/out/ao_alsa.c b/audio/out/ao_alsa.c
index e31e8012f8..2a7d694d95 100644
--- a/audio/out/ao_alsa.c
+++ b/audio/out/ao_alsa.c
@@ -252,7 +252,7 @@ static const int alsa_to_mp_channels[][2] = {
     {SND_CHMAP_TRR,     MP_SP(TBR)},
     {SND_CHMAP_TRC,     MP_SP(TBC)},
     {SND_CHMAP_MONO,    MP_SP(FC)},
-    {SND_CHMAP_NA,      MP_SPEAKER_ID_NA0},
+    {SND_CHMAP_NA,      MP_SPEAKER_ID_NA},
     {SND_CHMAP_LAST,    MP_SPEAKER_ID_COUNT}
 };
 
@@ -283,14 +283,9 @@ static int mp_chmap_from_alsa(struct mp_chmap *dst, snd_pcm_chmap_t *src)
     if (src->channels > MP_NUM_CHANNELS)
         return -1;
 
-    int next_na = MP_SPEAKER_ID_NA0;
-
     dst->num = src->channels;
-    for (int c = 0; c < dst->num; c++) {
+    for (int c = 0; c < dst->num; c++)
         dst->speaker[c] = find_mp_channel(src->pos[c]);
-        if (dst->speaker[c] == MP_SPEAKER_ID_NA0)
-            dst->speaker[c] = next_na++;
-    }
 
     return 0;
 }
diff --git a/audio/out/ao_coreaudio_chmap.c b/audio/out/ao_coreaudio_chmap.c
index f50bf4f3cc..8da0c4c6f0 100644
--- a/audio/out/ao_coreaudio_chmap.c
+++ b/audio/out/ao_coreaudio_chmap.c
@@ -51,7 +51,7 @@ static const int speaker_map[][2] = {
     { kAudioChannelLabel_HeadphonesLeft,       MP_SPEAKER_ID_DL   },
     { kAudioChannelLabel_HeadphonesRight,      MP_SPEAKER_ID_DR   },
 
-    { kAudioChannelLabel_Unknown,              MP_SPEAKER_ID_NA0  },
+    { kAudioChannelLabel_Unknown,              MP_SPEAKER_ID_NA   },
 
     { 0,                                       -1                 },
 };
@@ -150,12 +150,9 @@ static bool ca_layout_to_mp_chmap(struct ao *ao, AudioChannelLayout *layout,
         return false;
     }
 
-    int next_na = MP_SPEAKER_ID_NA0;
     for (int n = 0; n < l->mNumberChannelDescriptions; n++) {
         AudioChannelLabel label = l->mChannelDescriptions[n].mChannelLabel;
-        uint8_t speaker = ca_label_to_mp_speaker_id(label);
-        if (speaker == MP_SPEAKER_ID_NA0 && next_na < MP_SPEAKER_ID_NA_LAST)
-            speaker = next_na++;
+        int speaker = ca_label_to_mp_speaker_id(label);
         if (speaker < 0) {
             MP_VERBOSE(ao, "channel label=%u unusable to build channel "
                            "bitmap, skipping layout\n", (unsigned) label);
diff --git a/audio/out/ao_sndio.c b/audio/out/ao_sndio.c
index bbe616aebf..abce0efd36 100644
--- a/audio/out/ao_sndio.c
+++ b/audio/out/ao_sndio.c
@@ -99,7 +99,7 @@ static const struct mp_chmap sndio_layouts[MP_NUM_CHANNELS + 1] = {
     MP_CHMAP8(FL, FR, BL, BR, FC, LFE, SL, SR), // 7.1
     /* above is the fixed channel assignment for sndio, since we need to fill
        all channels and cannot insert silence, not all layouts are supported.
-       NOTE: MP_SPEAKER_ID_NA0-7 could be used to add padding channels. Keep
+       NOTE: MP_SPEAKER_ID_NA could be used to add padding channels. Keep
              in mind that they don't actually contain silence. */
 };