Dynamic Audio Buffer (1/3)

Add APIs in BluetoothA2dp to:
1. Get the supported type of the dynamic audio buffer.
2. Get the dynamic audio buffer millis.
3. Set dynamic audio buffer millis.

Add BufferConstraints class to access the buffer millis of different
codec.

Bug: 163968696
Tag: #feature
Test: Run dynamic audio buffer test
Change-Id: If097d94be861dbb0c4d8f67fe7caf70a99093e34

3 files changed, 315 insertions, 0 deletions

diff --git a/core/java/android/bluetooth/BluetoothA2dp.java b/core/java/android/bluetooth/BluetoothA2dp.java
index c0cb32346821..53cd8d5218fa 100644
--- a/core/java/android/bluetooth/BluetoothA2dp.java
+++ b/core/java/android/bluetooth/BluetoothA2dp.java
@@ -225,6 +225,39 @@ public final class BluetoothA2dp implements BluetoothProfile {
     @SystemApi
     public static final int OPTIONAL_CODECS_PREF_ENABLED = 1;
 
+    /** @hide */
+    @IntDef(prefix = "DYNAMIC_BUFFER_SUPPORT_", value = {
+            DYNAMIC_BUFFER_SUPPORT_NONE,
+            DYNAMIC_BUFFER_SUPPORT_A2DP_OFFLOAD,
+            DYNAMIC_BUFFER_SUPPORT_A2DP_SOFTWARE_ENCODING
+    })
+    @Retention(RetentionPolicy.SOURCE)
+    public @interface Type {}
+
+    /**
+     * Indicates the supported type of Dynamic Audio Buffer is not supported.
+     *
+     * @hide
+     */
+    @SystemApi
+    public static final int DYNAMIC_BUFFER_SUPPORT_NONE = 0;
+
+    /**
+     * Indicates the supported type of Dynamic Audio Buffer is A2DP offload.
+     *
+     * @hide
+     */
+    @SystemApi
+    public static final int DYNAMIC_BUFFER_SUPPORT_A2DP_OFFLOAD = 1;
+
+    /**
+     * Indicates the supported type of Dynamic Audio Buffer is A2DP software encoding.
+     *
+     * @hide
+     */
+    @SystemApi
+    public static final int DYNAMIC_BUFFER_SUPPORT_A2DP_SOFTWARE_ENCODING = 2;
+
     private BluetoothAdapter mAdapter;
     private final BluetoothProfileConnector<IBluetoothA2dp> mProfileConnector =
             new BluetoothProfileConnector(this, BluetoothProfile.A2DP, "BluetoothA2dp",
@@ -845,6 +878,87 @@ public final class BluetoothA2dp implements BluetoothProfile {
     }
 
     /**
+     * Get the supported type of the Dynamic Audio Buffer.
+     * <p>Possible return values are
+     * {@link #DYNAMIC_BUFFER_SUPPORT_NONE},
+     * {@link #DYNAMIC_BUFFER_SUPPORT_A2DP_OFFLOAD},
+     * {@link #DYNAMIC_BUFFER_SUPPORT_A2DP_SOFTWARE_ENCODING}.
+     *
+     * @return supported type of Dynamic Audio Buffer feature
+     *
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(Manifest.permission.BLUETOOTH_PRIVILEGED)
+    public @Type int getDynamicBufferSupport() {
+        if (VDBG) log("getDynamicBufferSupport()");
+        try {
+            final IBluetoothA2dp service = getService();
+            if (service != null && isEnabled()) {
+                return service.getDynamicBufferSupport();
+            }
+            if (service == null) Log.w(TAG, "Proxy not attached to service");
+            return DYNAMIC_BUFFER_SUPPORT_NONE;
+        } catch (RemoteException e) {
+            Log.e(TAG, "failed to get getDynamicBufferSupport, error: ", e);
+            return DYNAMIC_BUFFER_SUPPORT_NONE;
+        }
+    }
+
+    /**
+     * Return the record of {@link BufferConstraints} object that
+     * has the default/maximum/minimum audio buffer. This can be used to inform what the controller
+     * has support for the audio buffer.
+     *
+     * @return a record with {@link BufferConstraints} or null if report is unavailable
+     * or unsupported
+     *
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(Manifest.permission.BLUETOOTH_PRIVILEGED)
+    public @Nullable BufferConstraints getBufferConstraints() {
+        if (VDBG) log("getBufferConstraints()");
+        try {
+            final IBluetoothA2dp service = getService();
+            if (service != null && isEnabled()) {
+                return service.getBufferConstraints();
+            }
+            if (service == null) Log.w(TAG, "Proxy not attached to service");
+            return null;
+        } catch (RemoteException e) {
+            Log.e(TAG, "", e);
+            return null;
+        }
+    }
+
+    /**
+     * Set Dynamic Audio Buffer Size.
+     *
+     * @param codec audio codec
+     * @param value buffer millis
+     * @return true to indicate success, or false on immediate error
+     *
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(Manifest.permission.BLUETOOTH_PRIVILEGED)
+    public boolean setBufferMillis(@BluetoothCodecConfig.SourceCodecType int codec, int value) {
+        if (VDBG) log("setBufferMillis(" + codec + ", " + value + ")");
+        try {
+            final IBluetoothA2dp service = getService();
+            if (service != null && isEnabled()) {
+                return service.setBufferMillis(codec, value);
+            }
+            if (service == null) Log.w(TAG, "Proxy not attached to service");
+            return false;
+        } catch (RemoteException e) {
+            Log.e(TAG, "", e);
+            return false;
+        }
+    }
+
+    /**
      * Helper for converting a state to a string.
      *
      * For debug use only - strings are not internationalized.
diff --git a/core/java/android/bluetooth/BufferConstraint.java b/core/java/android/bluetooth/BufferConstraint.java
new file mode 100644
index 000000000000..cbffc788c35d
--- /dev/null
+++ b/core/java/android/bluetooth/BufferConstraint.java
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.bluetooth;
+
+import android.annotation.NonNull;
+import android.annotation.SystemApi;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+/**
+ * Stores a codec's constraints on buffering length in milliseconds.
+ *
+ * {@hide}
+ */
+@SystemApi
+public final class BufferConstraint implements Parcelable {
+
+    private static final String TAG = "BufferConstraint";
+    private int mDefaultMillis;
+    private int mMaxMillis;
+    private int mMinMillis;
+
+    public BufferConstraint(int defaultMillis, int maxMillis,
+            int minMillis) {
+        mDefaultMillis = defaultMillis;
+        mMaxMillis = maxMillis;
+        mMinMillis = minMillis;
+    }
+
+    BufferConstraint(Parcel in) {
+        mDefaultMillis = in.readInt();
+        mMaxMillis = in.readInt();
+        mMinMillis = in.readInt();
+    }
+
+    public static final @NonNull Parcelable.Creator<BufferConstraint> CREATOR =
+            new Parcelable.Creator<BufferConstraint>() {
+                public BufferConstraint createFromParcel(Parcel in) {
+                    return new BufferConstraint(in);
+                }
+
+                public BufferConstraint[] newArray(int size) {
+                    return new BufferConstraint[size];
+                }
+            };
+
+    @Override
+    public void writeToParcel(@NonNull Parcel out, int flags) {
+        out.writeInt(mDefaultMillis);
+        out.writeInt(mMaxMillis);
+        out.writeInt(mMinMillis);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    /**
+     * Get the default buffer millis
+     *
+     * @return default buffer millis
+     * @hide
+     */
+    @SystemApi
+    public int getDefaultMillis() {
+        return mDefaultMillis;
+    }
+
+    /**
+     * Get the maximum buffer millis
+     *
+     * @return maximum buffer millis
+     * @hide
+     */
+    @SystemApi
+    public int getMaxMillis() {
+        return mMaxMillis;
+    }
+
+    /**
+     * Get the minimum buffer millis
+     *
+     * @return minimum buffer millis
+     * @hide
+     */
+    @SystemApi
+    public int getMinMillis() {
+        return mMinMillis;
+    }
+}
diff --git a/core/java/android/bluetooth/BufferConstraints.java b/core/java/android/bluetooth/BufferConstraints.java
new file mode 100644
index 000000000000..7e5ec1e78435
--- /dev/null
+++ b/core/java/android/bluetooth/BufferConstraints.java
@@ -0,0 +1,96 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.bluetooth;
+
+import android.annotation.NonNull;
+import android.annotation.Nullable;
+import android.annotation.SystemApi;
+import android.os.Parcel;
+import android.os.Parcelable;
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+
+/**
+ * A parcelable collection of buffer constraints by codec type.
+ *
+ * {@hide}
+ */
+@SystemApi
+public final class BufferConstraints implements Parcelable {
+    public static final int BUFFER_CODEC_MAX_NUM = 32;
+
+    private static final String TAG = "BufferConstraints";
+
+    private Map<Integer, BufferConstraint> mBufferConstraints;
+    private List<BufferConstraint> mBufferConstraintList;
+
+    public BufferConstraints(@NonNull List<BufferConstraint>
+            bufferConstraintList) {
+
+        mBufferConstraintList = new ArrayList<BufferConstraint>(bufferConstraintList);
+        mBufferConstraints = new HashMap<Integer, BufferConstraint>();
+        for (int i = 0; i < BUFFER_CODEC_MAX_NUM; i++) {
+            mBufferConstraints.put(i, bufferConstraintList.get(i));
+        }
+    }
+
+    BufferConstraints(Parcel in) {
+        mBufferConstraintList = new ArrayList<BufferConstraint>();
+        mBufferConstraints = new HashMap<Integer, BufferConstraint>();
+        in.readList(mBufferConstraintList, BufferConstraint.class.getClassLoader());
+        for (int i = 0; i < mBufferConstraintList.size(); i++) {
+            mBufferConstraints.put(i, mBufferConstraintList.get(i));
+        }
+    }
+
+    public static final @NonNull Parcelable.Creator<BufferConstraints> CREATOR =
+            new Parcelable.Creator<BufferConstraints>() {
+                public BufferConstraints createFromParcel(Parcel in) {
+                    return new BufferConstraints(in);
+                }
+
+                public BufferConstraints[] newArray(int size) {
+                    return new BufferConstraints[size];
+                }
+            };
+
+    @Override
+    public void writeToParcel(@NonNull Parcel out, int flags) {
+        out.writeList(mBufferConstraintList);
+    }
+
+    @Override
+    public int describeContents() {
+        return 0;
+    }
+
+    /**
+     * Get the buffer constraints by codec type.
+     *
+     * @param codec Audio codec
+     * @return buffer constraints by codec type.
+     * @hide
+     */
+    @SystemApi
+    public @Nullable BufferConstraint getCodec(@BluetoothCodecConfig.SourceCodecType int codec) {
+        return mBufferConstraints.get(codec);
+    }
+}