Add receiver for HDMI plugged-in configuration changes.

library/src/main/java/com/google/android/exoplayer/audio/AudioCapabilities.java

+/*
+ * Copyright (C) 2014 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 com.google.android.exoplayer.audio;
+
+import com.google.android.exoplayer.util.Util;
+
+import android.annotation.TargetApi;
+import android.media.AudioFormat;
+
+import java.util.HashSet;
+import java.util.Set;
+
+/**
+ * Represents the set of audio formats a device is capable of playing back.
+ */
+@TargetApi(21)
+public final class AudioCapabilities {
+
+  private final Set<Integer> supportedEncodings;
+  private final int maxChannelCount;
+
+  /**
+   * Constructs new audio capabilities based on a set of supported encodings and a maximum channel
+   * count.
+   *
+   * @param supportedEncodings Supported audio encodings from {@link android.media.AudioFormat}'s
+   *     {@code ENCODING_*} constants.
+   * @param maxChannelCount The maximum number of audio channels that can be played simultaneously.
+   */
+  public AudioCapabilities(int[] supportedEncodings, int maxChannelCount) {
+    this.supportedEncodings = new HashSet<Integer>();
+    if (supportedEncodings != null) {
+      for (int i : supportedEncodings) {
+        this.supportedEncodings.add(i);
+      }
+    }
+    this.maxChannelCount = maxChannelCount;
+  }
+
+  /** Returns whether the device supports playback of AC-3. */
+  public boolean supportsAc3() {
+    return Util.SDK_INT >= 21 && supportedEncodings.contains(AudioFormat.ENCODING_AC3);
+  }
+
+  /** Returns whether the device supports playback of enhanced AC-3. */
+  public boolean supportsEAc3() {
+    return Util.SDK_INT >= 21 && supportedEncodings.contains(AudioFormat.ENCODING_E_AC3);
+  }
+
+  /** Returns whether the device supports playback of 16-bit PCM. */
+  public boolean supportsPcm() {
+    return supportedEncodings.contains(AudioFormat.ENCODING_PCM_16BIT);
+  }
+
+  /** Returns the maximum number of channels the device can play at the same time. */
+  public int getMaxChannelCount() {
+    return maxChannelCount;
+  }
+
+  @Override
+  public boolean equals(Object other) {
+    if (this == other) {
+      return true;
+    }
+    if (!(other instanceof AudioCapabilities)) {
+      return false;
+    }
+    AudioCapabilities audioCapabilities = (AudioCapabilities) other;
+    return supportedEncodings.equals(audioCapabilities.supportedEncodings)
+        && maxChannelCount == audioCapabilities.maxChannelCount;
+  }
+
+  @Override
+  public int hashCode() {
+    return maxChannelCount + 31 * supportedEncodings.hashCode();
+  }
+
+  @Override
+  public String toString() {
+    return "AudioCapabilities[maxChannelCount=" + maxChannelCount
+        + ", supportedEncodings=" + supportedEncodings + "]";
+  }
+
+}

library/src/main/java/com/google/android/exoplayer/audio/AudioCapabilitiesReceiver.java

+/*
+ * Copyright (C) 2014 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 com.google.android.exoplayer.audio;
+
+import com.google.android.exoplayer.util.Assertions;
+import com.google.android.exoplayer.util.Util;
+
+import android.annotation.TargetApi;
+import android.content.BroadcastReceiver;
+import android.content.Context;
+import android.content.Intent;
+import android.content.IntentFilter;
+import android.media.AudioFormat;
+import android.media.AudioManager;
+
+/**
+ * Notifies a listener when the audio playback capabilities change. Call {@link #register} to start
+ * receiving notifications, and {@link #unregister} to stop.
+ */
+public final class AudioCapabilitiesReceiver {
+
+  /** Listener notified when audio capabilities change. */
+  public interface Listener {
+
+    /** Called when the audio capabilities change. */
+    void onAudioCapabilitiesChanged(AudioCapabilities audioCapabilities);
+
+  }
+
+  /** Default to stereo PCM on SDK <= 21 and when HDMI is unplugged. */
+  private static final AudioCapabilities DEFAULT_AUDIO_CAPABILITIES =
+      new AudioCapabilities(new int[] {AudioFormat.ENCODING_PCM_16BIT}, 2);
+
+  private final Context context;
+  private final Listener listener;
+  private final BroadcastReceiver receiver;
+
+  /**
+   * Constructs a new audio capabilities receiver.
+   *
+   * @param context Application context for registering to receive broadcasts.
+   * @param listener Listener to notify when audio capabilities change.
+   */
+  public AudioCapabilitiesReceiver(Context context, Listener listener) {
+    this.context = Assertions.checkNotNull(context);
+    this.listener = Assertions.checkNotNull(listener);
+    this.receiver = Util.SDK_INT >= 21 ? new HdmiAudioPlugBroadcastReceiver() : null;
+  }
+
+  /**
+   * Registers to notify the listener when audio capabilities change. The listener will immediately
+   * receive the current audio capabilities. It is important to call {@link #unregister} so that
+   * the listener can be garbage collected.
+   */
+  @TargetApi(21)
+  public void register() {
+    if (receiver != null) {
+      context.registerReceiver(receiver, new IntentFilter(AudioManager.ACTION_HDMI_AUDIO_PLUG));
+    }
+
+    listener.onAudioCapabilitiesChanged(DEFAULT_AUDIO_CAPABILITIES);
+  }
+
+  /** Unregisters to stop notifying the listener when audio capabilities change. */
+  public void unregister() {
+    if (receiver != null) {
+      context.unregisterReceiver(receiver);
+    }
+  }
+
+  @TargetApi(21)
+  private final class HdmiAudioPlugBroadcastReceiver extends BroadcastReceiver {
+
+    @Override
+    public void onReceive(Context context, Intent intent) {
+      String action = intent.getAction();
+      if (!action.equals(AudioManager.ACTION_HDMI_AUDIO_PLUG)) {
+        return;
+      }
+
+      listener.onAudioCapabilitiesChanged(
+          new AudioCapabilities(intent.getIntArrayExtra(AudioManager.EXTRA_ENCODINGS),
+              intent.getIntExtra(AudioManager.EXTRA_MAX_CHANNEL_COUNT, 0)));
+    }
+
+  }
+
+}