op/aaudio: Implement AAudio output plugin

Support native audio on Android 8.1 and later.

- Better battery life.
- Configurable latency.
- Configurable capture policy.
- Configurable sharing mode.
- Configurable spatialization.
- Full multi-channel audio support.
- Supports `pause_on_output_change`.

Doc/cmus.txt

@@ -1130,13 +1130,13 @@ mpris (true)
 
 	Note: This flag has no effect if cmus was compiled without MPRIS support.
 
-output_plugin [roar, pulse, alsa, arts, oss, sndio, sun, coreaudio]
+output_plugin [roar, pulse, alsa, arts, oss, sndio, sun, coreaudio, aaudio]
 	Name of output plugin.
 
 pause_on_output_change (false)
     Pauses playback when the audio output changes.
 
-    Supported output plugins: pulse.
+    Supported output plugins: pulse, aaudio.
 
 pl_env_vars
 	Comma separated list of environment variables to substitute when saving
@@ -1484,6 +1484,35 @@ dsp.jack.resampling_quality
 	2 (default) is high quality but more CPU intensive. This option is only
 	available if cmus was compiled with libsamplerate support.
 
+dsp.aaudio.performance_mode (power_saving) [power_saving, none]
+	Set the requested performance mode. If "power_saving", battery life is
+	prioritized over low latency. If "none", battery life is balanced with
+	low latency.
+
+	This option requires restarting cmus.
+
+dsp.aaudio.allowed_capture (all) [all, system, none]
+	Specify whether the audio may or may not be captured by other apps or
+	the system.
+
+	This option is only supported on Android 10+ (API 29) and requires
+	restarting cmus.
+
+dsp.aaudio.sharing_mode (shared) [shared, exclusive]
+	Request a mode for sharing the device. This is done on a best-effort
+	basis, and the requested sharing mode may not be available.
+
+	This option requires restarting cmus.
+
+dsp.aaudio.disable_spatialization (false)
+	If true, disables Android's built-in audio spatializer even if it is
+	enabled for the current audio output. Note that spatialization only
+	applies to audio with at least 4 channels. See
+	https://developer.android.com/media/grow/spatial-audio for more details.
+
+	This option is only supported on Android 12L+ (API 32) and requires
+	restarting cmus.
+
 input.cdio.cddb_url
 	CDDB URL (default: freedb.freedb.org:8880). Uses HTTP if prefixed with
 	"http://" (e.g.: http://freedb.musicbrainz.org:80/~cddb/cddb.cgi). Set

Makefile

@@ -180,6 +180,7 @@ ao-objs			:= op/ao.lo
 coreaudio-objs		:= op/coreaudio.lo
 waveout-objs		:= op/waveout.lo
 roar-objs               := op/roar.lo
+aaudio-objs		:= op/aaudio.lo
 
 op-$(CONFIG_PULSE)	+= op/pulse.so
 op-$(CONFIG_ALSA)	+= op/alsa.so
@@ -192,6 +193,7 @@ op-$(CONFIG_COREAUDIO)	+= op/coreaudio.so
 op-$(CONFIG_AO)		+= op/ao.so
 op-$(CONFIG_WAVEOUT)	+= op/waveout.so
 op-$(CONFIG_ROAR)       += op/roar.so
+op-$(CONFIG_AAUDIO)	+= op/aaudio.so
 
 $(pulse-objs): CFLAGS		+= $(PULSE_CFLAGS)
 $(alsa-objs): CFLAGS		+= $(ALSA_CFLAGS)
@@ -204,6 +206,7 @@ $(ao-objs):   CFLAGS		+= $(AO_CFLAGS)
 $(coreaudio-objs): CFLAGS	+= $(COREAUDIO_CFLAGS)
 $(waveout-objs): CFLAGS 	+= $(WAVEOUT_CFLAGS)
 $(roar-objs): CFLAGS		+= $(ROAR_CFLAGS)
+$(aaudio-objs): CFLAGS		+= $(AAUDIO_CFLAGS)
 
 op/pulse.so: $(pulse-objs) $(libcmus-y)
 	$(call cmd,ld_dl,$(PULSE_LIBS))
@@ -237,6 +240,9 @@ op/waveout.so: $(waveout-objs) $(libcmus-y)
 
 op/roar.so: $(roar-objs) $(libcmus-y)
 	$(call cmd,ld_dl,$(ROAR_LIBS))
+
+op/aaudio.so: $(aaudio-objs) $(libcmus-y)
+	$(call cmd,ld_dl,$(AAUDIO_LIBS))
 # }}}
 
 # man {{{

configure

@@ -498,6 +498,38 @@ check_ffmpeg()
 	return 1
 }
 
+aaudio_code="
+#include <aaudio/AAudio.h>
+int main() {
+	// ensure basic aaudio support
+	if (__builtin_available(android 26, *)) {
+		AAudioStreamBuilder *bld;
+		AAudio_createStreamBuilder(&bld);
+
+		// ensure we have at least api 32 headers
+		if (__builtin_available(android 32, *)) {
+			AAudioStreamBuilder_setChannelMask(bld, AAUDIO_CHANNEL_9POINT1POINT6);
+		}
+	}
+	return 0;
+}
+"
+
+check_aaudio()
+{
+	check_header aaudio/AAudio.h || return $?
+	check_library AAUDIO "-D__ANDROID_UNAVAILABLE_SYMBOLS_ARE_WEAK__ -Werror=unguarded-availability" "-Wl,--no-as-needed -laaudio" || return $?
+
+	msg_checking "for working aaudio api 32 linkage"
+	if try_compile_link "$aaudio_code" $AAUDIO_CFLAGS $AAUDIO_LIBS
+	then
+		msg_result yes
+		return 0
+	fi
+	msg_result no
+	return 1
+}
+
 check_string_function()
 {
 	msg_checking "for function $1"
@@ -543,6 +575,7 @@ Options:
 
 Optional Features: y/n
   CONFIG_AAC            AAC (.aac, audio/aac, audio/aacp)               [auto]
+  CONFIG_AAUDIO         Android 8.0+ native audio output                [auto]
   CONFIG_ALSA           ALSA                                            [auto]
   CONFIG_AO             Libao cross-platform audio library              [auto]
   CONFIG_ARTS           ARTS                                            [auto]
@@ -646,6 +679,7 @@ check check_sndio      CONFIG_SNDIO
 check check_sun        CONFIG_SUN
 check check_waveout    CONFIG_WAVEOUT
 check check_roar       CONFIG_ROAR
+check check_aaudio     CONFIG_AAUDIO
 
 # discid is only needed if at least one cdda plugin is active
 test -z "$CONFIG_DISCID" && CONFIG_DISCID=a
@@ -687,6 +721,6 @@ makefile_vars \
 	CONFIG_MAD CONFIG_MIKMOD CONFIG_MODPLUG CONFIG_MP4 CONFIG_MPC \
 	CONFIG_MPRIS CONFIG_OPUS CONFIG_OSS CONFIG_PULSE CONFIG_ROAR \
 	CONFIG_SAMPLERATE CONFIG_SNDIO CONFIG_SUN CONFIG_VORBIS CONFIG_VTX \
-	CONFIG_WAV CONFIG_WAVEOUT CONFIG_WAVPACK CONFIG_BASS
+	CONFIG_WAV CONFIG_WAVEOUT CONFIG_WAVPACK CONFIG_BASS CONFIG_AAUDIO
 
 generate_config_mk