ao_coreaudio: move channel mapping away from utils

Channel mapping functions are only used in the AUHAL based coreaudio, so move
them there.

1 files changed, 128 insertions, 0 deletions

diff --git a/audio/out/ao_coreaudio.c b/audio/out/ao_coreaudio.c
index c8feb56e7a..59846cd605 100644
--- a/audio/out/ao_coreaudio.c
+++ b/audio/out/ao_coreaudio.c
@@ -35,6 +35,9 @@ struct priv {
     int opt_list;
 };
 
+bool ca_layout_to_mp_chmap(struct ao *ao, AudioChannelLayout *layout,
+                           struct mp_chmap *chmap);
+
 static OSStatus render_cb_lpcm(void *ctx, AudioUnitRenderActionFlags *aflags,
                               const AudioTimeStamp *ts, UInt32 bus,
                               UInt32 frames, AudioBufferList *buffer_list)
@@ -244,6 +247,131 @@ static void uninit(struct ao *ao)
     AudioComponentInstanceDispose(p->audio_unit);
 }
 
+// Channel Mapping functions
+static const int speaker_map[][2] = {
+    { kAudioChannelLabel_Left,                 MP_SPEAKER_ID_FL   },
+    { kAudioChannelLabel_Right,                MP_SPEAKER_ID_FR   },
+    { kAudioChannelLabel_Center,               MP_SPEAKER_ID_FC   },
+    { kAudioChannelLabel_LFEScreen,            MP_SPEAKER_ID_LFE  },
+    { kAudioChannelLabel_LeftSurround,         MP_SPEAKER_ID_BL   },
+    { kAudioChannelLabel_RightSurround,        MP_SPEAKER_ID_BR   },
+    { kAudioChannelLabel_LeftCenter,           MP_SPEAKER_ID_FLC  },
+    { kAudioChannelLabel_RightCenter,          MP_SPEAKER_ID_FRC  },
+    { kAudioChannelLabel_CenterSurround,       MP_SPEAKER_ID_BC   },
+    { kAudioChannelLabel_LeftSurroundDirect,   MP_SPEAKER_ID_SL   },
+    { kAudioChannelLabel_RightSurroundDirect,  MP_SPEAKER_ID_SR   },
+    { kAudioChannelLabel_TopCenterSurround,    MP_SPEAKER_ID_TC   },
+    { kAudioChannelLabel_VerticalHeightLeft,   MP_SPEAKER_ID_TFL  },
+    { kAudioChannelLabel_VerticalHeightCenter, MP_SPEAKER_ID_TFC  },
+    { kAudioChannelLabel_VerticalHeightRight,  MP_SPEAKER_ID_TFR  },
+    { kAudioChannelLabel_TopBackLeft,          MP_SPEAKER_ID_TBL  },
+    { kAudioChannelLabel_TopBackCenter,        MP_SPEAKER_ID_TBC  },
+    { kAudioChannelLabel_TopBackRight,         MP_SPEAKER_ID_TBR  },
+
+    // unofficial extensions
+    { kAudioChannelLabel_RearSurroundLeft,     MP_SPEAKER_ID_SDL  },
+    { kAudioChannelLabel_RearSurroundRight,    MP_SPEAKER_ID_SDR  },
+    { kAudioChannelLabel_LeftWide,             MP_SPEAKER_ID_WL   },
+    { kAudioChannelLabel_RightWide,            MP_SPEAKER_ID_WR   },
+    { kAudioChannelLabel_LFE2,                 MP_SPEAKER_ID_LFE2 },
+
+    { kAudioChannelLabel_HeadphonesLeft,       MP_SPEAKER_ID_DL   },
+    { kAudioChannelLabel_HeadphonesRight,      MP_SPEAKER_ID_DR   },
+
+    { kAudioChannelLabel_Unknown,              -1 },
+};
+
+static int ca_label_to_mp_speaker_id(AudioChannelLabel label)
+{
+    for (int i = 0; speaker_map[i][1] >= 0; i++)
+        if (speaker_map[i][0] == label)
+            return speaker_map[i][1];
+    return -1;
+}
+
+static void ca_log_layout(struct ao *ao, AudioChannelLayout *layout)
+{
+    if (!mp_msg_test(ao->log, MSGL_V))
+        return;
+
+    AudioChannelDescription *descs = layout->mChannelDescriptions;
+
+    MP_VERBOSE(ao, "layout: tag: <%d>, bitmap: <%d>, "
+                   "descriptions <%d>\n",
+                   layout->mChannelLayoutTag,
+                   layout->mChannelBitmap,
+                   layout->mNumberChannelDescriptions);
+
+    for (int i = 0; i < layout->mNumberChannelDescriptions; i++) {
+        AudioChannelDescription d = descs[i];
+        MP_VERBOSE(ao, " - description %d: label <%d, %d>, flags: <%u>, "
+                       "coords: <%f, %f, %f>\n", i,
+                       d.mChannelLabel,
+                       ca_label_to_mp_speaker_id(d.mChannelLabel),
+                       d.mChannelFlags,
+                       d.mCoordinates[0],
+                       d.mCoordinates[1],
+                       d.mCoordinates[2]);
+    }
+}
+
+bool ca_layout_to_mp_chmap(struct ao *ao, AudioChannelLayout *layout,
+                           struct mp_chmap *chmap)
+{
+    AudioChannelLayoutTag tag  = layout->mChannelLayoutTag;
+    uint32_t layout_size       = sizeof(layout);
+    OSStatus err;
+
+    if (tag == kAudioChannelLayoutTag_UseChannelBitmap) {
+        err = AudioFormatGetProperty(kAudioFormatProperty_ChannelLayoutForBitmap,
+                                     sizeof(uint32_t),
+                                     &layout->mChannelBitmap,
+                                     &layout_size,
+                                     layout);
+        CHECK_CA_ERROR("failed to convert channel bitmap to descriptions");
+    } else if (tag != kAudioChannelLayoutTag_UseChannelDescriptions) {
+        err = AudioFormatGetProperty(kAudioFormatProperty_ChannelLayoutForTag,
+                                     sizeof(AudioChannelLayoutTag),
+                                     &layout->mChannelLayoutTag,
+                                     &layout_size,
+                                     layout);
+        CHECK_CA_ERROR("failed to convert channel tag to descriptions");
+    }
+
+    ca_log_layout(ao, layout);
+
+    // If the channel layout uses channel descriptions, from my
+    // experiments there are there three possibile cases:
+    // * The description has a label kAudioChannelLabel_Unknown:
+    //   Can't do anything about this (looks like non surround
+    //   layouts are like this).
+    // * The description uses positional information: this in
+    //   theory could be used but one would have to map spatial
+    //   positions to labels which is not really feasible.
+    // * The description has a well known label which can be mapped
+    //   to the waveextensible definition: this is the kind of
+    //   descriptions we process here.
+
+    for (int n = 0; n < layout->mNumberChannelDescriptions; n++) {
+        AudioChannelLabel label = layout->mChannelDescriptions[n].mChannelLabel;
+        uint8_t speaker = ca_label_to_mp_speaker_id(label);
+        if (label == kAudioChannelLabel_Unknown)
+            continue;
+        if (speaker < 0) {
+            MP_VERBOSE(ao, "channel label=%d unusable to build channel "
+                           "bitmap, skipping layout\n", label);
+        } else {
+            chmap->speaker[n] = speaker;
+            chmap->num = n + 1;
+        }
+    }
+
+    return chmap->num > 0;
+coreaudio_error:
+    ca_log_layout(ao, layout);
+    return false;
+}
+
 #define OPT_BASE_STRUCT struct priv
 
 const struct ao_driver audio_out_coreaudio = {