AudioAPI: a few updates (#184)

* AudioAPI: simplify code

* AudioAPI: remove volume info

Redundunt with the introduction of VolumeAPI

* AudioAPI: remove PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED

It does not seem to have a point for us to get this property as
it is not very clear what it actually reflects.

We have not been getting PROPERTY_SUPPORT_MIC_NEAR_ULTRASOUND and
PROPERTY_SUPPORT_SPEAKER_NEAR_ULTRASOUND either.

In fact, properties from getProperty() tend to be rather useless.
PROPERTY_OUTPUT_FRAMES_PER_BUFFER and PROPERTY_OUTPUT_SAMPLE_RATE
are kept only to show that, they should NOT be used to optimize
any player in audio output, as they do not change as per the
current sink, not like the values from the AudioTrack methods do.

* AudioAPI: order output

* AudioAPI: check info in PERFORMANCE_MODE_POWER_SAVING

When setPerformanceMode was introduced in Android O, it was
introduced with three possible modes, namely:

PERFORMANCE_MODE_NONE (default)
PERFORMANCE_MODE_LOW_LATENCY
PERFORMANCE_MODE_POWER_SAVING

While PERFORMANCE_MODE_NONE essentially causes tracks to be routed
to the deep buffer mixer path on my phone (as
PERFORMANCE_MODE_POWER_SAVING does), it may not be the case on
every single device.

Therefore, check info with track in PERFORMANCE_MODE_POWER_SAVING,
compare it against that of the default PERFORMANCE_MODE_NONE, and
print it out if they are not the same.

Note: shouldEnablePowerSaving for PERFORMANCE_MODE_NONE always
returns false for SAMPLE_RATE_UNSPECIFIED as of the current
AudioTrack.java.

app/src/main/java/com/termux/api/AudioAPI.java

@@ -16,86 +16,76 @@ static void onReceive(TermuxApiReceiver apiReceiver, final Context context, Inte
         AudioManager am = (AudioManager) context.getSystemService(Context.AUDIO_SERVICE);
         final String SampleRate = am.getProperty(AudioManager.PROPERTY_OUTPUT_SAMPLE_RATE);
         final String framesPerBuffer = am.getProperty(AudioManager.PROPERTY_OUTPUT_FRAMES_PER_BUFFER);
-        final String AudioUnprocessed;
-        if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
-            AudioUnprocessed = am.getProperty(AudioManager.PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED);
-        } else {
-            AudioUnprocessed = null;
-        }
-        final int volume_level = am.getStreamVolume(AudioManager.STREAM_MUSIC);
-        final int maxvolume_level = am.getStreamMaxVolume(AudioManager.STREAM_MUSIC);
         final boolean bluetootha2dp = am.isBluetoothA2dpOn();
         final boolean wiredhs = am.isWiredHeadsetOn();
 
-        int _sr, _bs, _sr_ll, _bs_ll, _nosr;
-        _sr = _bs = _sr_ll = _bs_ll = _nosr = 0;
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
-            int[] modes = {AudioTrack.PERFORMANCE_MODE_POWER_SAVING,
-                           AudioTrack.PERFORMANCE_MODE_LOW_LATENCY};
-            for (int mode: modes) {
-                AudioTrack at = new AudioTrack.Builder()
+        final int sr, bs, sr_ll, bs_ll, sr_ps, bs_ps, nosr;
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
+            nosr = 0;
+            AudioTrack at;
+            at = new AudioTrack.Builder()
+                .setBufferSizeInBytes(4) // one 16bit 2ch frame
+                .build();
+            sr = at.getSampleRate();
+            bs = at.getBufferSizeInFrames();
+            at.release();
+
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                at = new AudioTrack.Builder()
                     .setBufferSizeInBytes(4) // one 16bit 2ch frame
-                    .setPerformanceMode(mode)
+                    .setPerformanceMode(AudioTrack.PERFORMANCE_MODE_LOW_LATENCY)
                     .build();
-                if (mode == AudioTrack.PERFORMANCE_MODE_POWER_SAVING) {
-                    _sr = at.getSampleRate();
-                    _bs = at.getBufferSizeInFrames();
-                } else if (mode == AudioTrack.PERFORMANCE_MODE_LOW_LATENCY) {
-                    _sr_ll = at.getSampleRate();
-                    _bs_ll = at.getBufferSizeInFrames();
-                }
-                at.release();
-            }
-        } else if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
-            int[] flags = {0,AudioAttributes.FLAG_LOW_LATENCY};
-            for (int flag: flags) {
+            } else {
                 AudioAttributes aa = new AudioAttributes.Builder()
-                    .setFlags(flag)
+                    .setFlags(AudioAttributes.FLAG_LOW_LATENCY)
                     .build();
-                AudioTrack at = new AudioTrack.Builder()
+                at = new AudioTrack.Builder()
                     .setAudioAttributes(aa)
                     .setBufferSizeInBytes(4) // one 16bit 2ch frame
                     .build();
-                if (flag == 0) {
-                    _sr = at.getSampleRate();
-                    _bs = at.getBufferSizeInFrames();
-                } else if (flag == AudioAttributes.FLAG_LOW_LATENCY) {
-                    _sr_ll = at.getSampleRate();
-                    _bs_ll = at.getBufferSizeInFrames();
-                }
-                at.release();
+            }
+            sr_ll = at.getSampleRate();
+            bs_ll = at.getBufferSizeInFrames();
+            at.release();
+
+            if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.O) {
+                at = new AudioTrack.Builder()
+                    .setBufferSizeInBytes(4) // one 16bit 2ch frame
+                    .setPerformanceMode(AudioTrack.PERFORMANCE_MODE_POWER_SAVING)
+                    .build();
+		sr_ps = at.getSampleRate();
+		bs_ps = at.getBufferSizeInFrames();
+		at.release();
+            } else {
+		sr_ps = sr;
+		bs_ps = bs;
             }
         } else {
-            _nosr = AudioTrack.getNativeOutputSampleRate(AudioManager.STREAM_MUSIC);
+            sr = bs = sr_ll = bs_ll = sr_ps = bs_ps = 0;
+            nosr = AudioTrack.getNativeOutputSampleRate(AudioManager.STREAM_MUSIC);
         }
-        final int sr = _sr;
-        final int bs = _bs;
-        final int sr_ll = _sr_ll;
-        final int bs_ll = _bs_ll;
-        final int nosr = _nosr;
 
         ResultReturner.returnData(apiReceiver, intent, new ResultReturner.ResultJsonWriter() {
             public void writeJson(JsonWriter out) throws Exception {
                 out.beginObject();
                 out.name("PROPERTY_OUTPUT_SAMPLE_RATE").value(SampleRate);
                 out.name("PROPERTY_OUTPUT_FRAMES_PER_BUFFER").value(framesPerBuffer);
-                if (android.os.Build.VERSION.SDK_INT >= android.os.Build.VERSION_CODES.N) {
-                    out.name("PROPERTY_SUPPORT_AUDIO_SOURCE_UNPROCESSED").value(AudioUnprocessed);
-                }
-                out.name("STREAM_MUSIC_VOLUME").value(volume_level);
-                out.name("STREAM_MUSIC_MAXVOLUME").value(maxvolume_level);
-                out.name("BLUETOOTH_A2DP_IS_ON").value(bluetootha2dp);
-                out.name("WIREDHEADSET_IS_CONNECTED").value(wiredhs);
                 if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
                     out.name("AUDIOTRACK_SAMPLE_RATE").value(sr);
                     out.name("AUDIOTRACK_BUFFER_SIZE_IN_FRAMES").value(bs);
                     if (sr_ll != sr || bs_ll != bs) { // all or nothing
                         out.name("AUDIOTRACK_SAMPLE_RATE_LOW_LATENCY").value(sr_ll);
                         out.name("AUDIOTRACK_BUFFER_SIZE_IN_FRAMES_LOW_LATENCY").value(bs_ll);
                     }
+                    if (sr_ps != sr || bs_ps != bs) { // all or nothing
+                        out.name("AUDIOTRACK_SAMPLE_RATE_POWER_SAVING").value(sr_ps);
+                        out.name("AUDIOTRACK_BUFFER_SIZE_IN_FRAMES_POWER_SAVING").value(bs_ps);
+                    }
                 } else {
                     out.name("AUDIOTRACK_NATIVE_OUTPUT_SAMPLE_RATE").value(nosr);
                 }
+                out.name("BLUETOOTH_A2DP_IS_ON").value(bluetootha2dp);
+                out.name("WIREDHEADSET_IS_CONNECTED").value(wiredhs);
                 out.endObject();
             }
         });