Fix incorrect channel configuration for 8 ch pre-M

AudioTrack checks the channel configuration against a mask of allowed channels.
Before Android M the check in getMinBufferSize would always fail for 8 channel
output.

For Android L constants are available to build the required channel
configuration for a conventional 7.1 setup and these constants are part of the
allowed channels mask, so switch to using them.

Before Android L the constants for 7.1 aren't in the allowed channels mask, so
discard channels to give a 5.1 stream.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=206307892

library/core/src/main/java/com/google/android/exoplayer2/C.java

@@ -194,13 +194,6 @@ public final class C {
   public static final int ENCODING_DOLBY_TRUEHD = AudioFormat.ENCODING_DOLBY_TRUEHD;
   public static final int ENCODING_DOLBY_TRUEHD = AudioFormat.ENCODING_DOLBY_TRUEHD;
 
 
   /**
   /**
-   * @see AudioFormat#CHANNEL_OUT_7POINT1_SURROUND
-   */
-  @SuppressWarnings("deprecation")
-  public static final int CHANNEL_OUT_7POINT1_SURROUND = Util.SDK_INT < 23
-      ? AudioFormat.CHANNEL_OUT_7POINT1 : AudioFormat.CHANNEL_OUT_7POINT1_SURROUND;
-
-  /**
    * Stream types for an {@link android.media.AudioTrack}.
    * Stream types for an {@link android.media.AudioTrack}.
    */
    */
   @Retention(RetentionPolicy.SOURCE)
   @Retention(RetentionPolicy.SOURCE)

library/core/src/main/java/com/google/android/exoplayer2/audio/DefaultAudioSink.java

@@ -416,6 +416,16 @@ public final class DefaultAudioSink implements AudioSink {
     @C.Encoding int encoding = inputEncoding;
     @C.Encoding int encoding = inputEncoding;
     boolean processingEnabled = isInputPcm && inputEncoding != C.ENCODING_PCM_FLOAT;
     boolean processingEnabled = isInputPcm && inputEncoding != C.ENCODING_PCM_FLOAT;
     canApplyPlaybackParameters = processingEnabled && !shouldConvertHighResIntPcmToFloat;
     canApplyPlaybackParameters = processingEnabled && !shouldConvertHighResIntPcmToFloat;
+
+    if (Util.SDK_INT < 21 && channelCount == 8 && outputChannels == null) {
+      // AudioTrack doesn't support 8 channel output before Android L. Discard the last two (side)
+      // channels to give a 6 channel stream that is supported.
+      outputChannels = new int[6];
+      for (int i = 0; i < outputChannels.length; i++) {
+        outputChannels[i] = i;
+      }
+    }
+
     if (processingEnabled) {
     if (processingEnabled) {
       trimmingAudioProcessor.setTrimFrameCount(trimStartFrames, trimEndFrames);
       trimmingAudioProcessor.setTrimFrameCount(trimStartFrames, trimEndFrames);
       channelMappingAudioProcessor.setChannelMap(outputChannels);
       channelMappingAudioProcessor.setChannelMap(outputChannels);
@@ -433,55 +443,9 @@ public final class DefaultAudioSink implements AudioSink {
       }
       }
     }
     }
 
 
-    int channelConfig;
-    switch (channelCount) {
-      case 1:
-        channelConfig = AudioFormat.CHANNEL_OUT_MONO;
-        break;
-      case 2:
-        channelConfig = AudioFormat.CHANNEL_OUT_STEREO;
-        break;
-      case 3:
-        channelConfig = AudioFormat.CHANNEL_OUT_STEREO | AudioFormat.CHANNEL_OUT_FRONT_CENTER;
-        break;
-      case 4:
-        channelConfig = AudioFormat.CHANNEL_OUT_QUAD;
-        break;
-      case 5:
-        channelConfig = AudioFormat.CHANNEL_OUT_QUAD | AudioFormat.CHANNEL_OUT_FRONT_CENTER;
-        break;
-      case 6:
-        channelConfig = AudioFormat.CHANNEL_OUT_5POINT1;
-        break;
-      case 7:
-        channelConfig = AudioFormat.CHANNEL_OUT_5POINT1 | AudioFormat.CHANNEL_OUT_BACK_CENTER;
-        break;
-      case 8:
-        channelConfig = C.CHANNEL_OUT_7POINT1_SURROUND;
-        break;
-      default:
-        throw new ConfigurationException("Unsupported channel count: " + channelCount);
-    }
-
-    // Workaround for overly strict channel configuration checks on nVidia Shield.
-    if (Util.SDK_INT <= 23 && "foster".equals(Util.DEVICE) && "NVIDIA".equals(Util.MANUFACTURER)) {
-      switch (channelCount) {
-        case 7:
-          channelConfig = C.CHANNEL_OUT_7POINT1_SURROUND;
-          break;
-        case 3:
-        case 5:
-          channelConfig = AudioFormat.CHANNEL_OUT_5POINT1;
-          break;
-        default:
-          break;
-      }
-    }
-
-    // Workaround for Nexus Player not reporting support for mono passthrough.
-    // (See [Internal: b/34268671].)
-    if (Util.SDK_INT <= 25 && "fugu".equals(Util.DEVICE) && !isInputPcm && channelCount == 1) {
-      channelConfig = AudioFormat.CHANNEL_OUT_STEREO;
+    int channelConfig = getChannelConfig(channelCount, isInputPcm);
+    if (channelConfig == AudioFormat.CHANNEL_INVALID) {
+      throw new ConfigurationException("Unsupported channel count: " + channelCount);
     }
     }
 
 
     if (!flush
     if (!flush
@@ -1170,6 +1134,25 @@ public final class DefaultAudioSink implements AudioSink {
         : toIntPcmAvailableAudioProcessors;
         : toIntPcmAvailableAudioProcessors;
   }
   }
 
 
+  private static int getChannelConfig(int channelCount, boolean isInputPcm) {
+    // Workaround for overly strict channel configuration checks on nVidia Shield.
+    if (Util.SDK_INT <= 23 && "foster".equals(Util.DEVICE) && "NVIDIA".equals(Util.MANUFACTURER)) {
+      if (channelCount == 7) {
+        channelCount = 8;
+      } else if (channelCount == 3 || channelCount == 5) {
+        channelCount = 6;
+      }
+    }
+
+    // Workaround for Nexus Player not reporting support for mono passthrough.
+    // (See [Internal: b/34268671].)
+    if (Util.SDK_INT <= 25 && "fugu".equals(Util.DEVICE) && !isInputPcm && channelCount == 1) {
+      channelCount = 2;
+    }
+
+    return Util.getAudioTrackChannelConfig(channelCount);
+  }
+
   private static int getFramesPerEncodedSample(@C.Encoding int encoding, ByteBuffer buffer) {
   private static int getFramesPerEncodedSample(@C.Encoding int encoding, ByteBuffer buffer) {
     if (encoding == C.ENCODING_DTS || encoding == C.ENCODING_DTS_HD) {
     if (encoding == C.ENCODING_DTS || encoding == C.ENCODING_DTS_HD) {
       return DtsUtil.parseDtsAudioSampleCount(buffer);
       return DtsUtil.parseDtsAudioSampleCount(buffer);

library/core/src/main/java/com/google/android/exoplayer2/util/Util.java

@@ -25,6 +25,7 @@ import android.content.pm.PackageInfo;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.content.pm.PackageManager.NameNotFoundException;
 import android.graphics.Point;
 import android.graphics.Point;
+import android.media.AudioFormat;
 import android.net.ConnectivityManager;
 import android.net.ConnectivityManager;
 import android.net.NetworkInfo;
 import android.net.NetworkInfo;
 import android.net.Uri;
 import android.net.Uri;
@@ -1159,6 +1160,47 @@ public final class Util {
   }
   }
 
 
   /**
   /**
+   * Returns the audio track channel configuration for the given channel count, or {@link
+   * AudioFormat#CHANNEL_INVALID} if output is not poossible.
+   *
+   * @param channelCount The number of channels in the input audio.
+   * @return The channel configuration or {@link AudioFormat#CHANNEL_INVALID} if output is not
+   *     possible.
+   */
+  public static int getAudioTrackChannelConfig(int channelCount) {
+    switch (channelCount) {
+      case 1:
+        return AudioFormat.CHANNEL_OUT_MONO;
+      case 2:
+        return AudioFormat.CHANNEL_OUT_STEREO;
+      case 3:
+        return AudioFormat.CHANNEL_OUT_STEREO | AudioFormat.CHANNEL_OUT_FRONT_CENTER;
+      case 4:
+        return AudioFormat.CHANNEL_OUT_QUAD;
+      case 5:
+        return AudioFormat.CHANNEL_OUT_QUAD | AudioFormat.CHANNEL_OUT_FRONT_CENTER;
+      case 6:
+        return AudioFormat.CHANNEL_OUT_5POINT1;
+      case 7:
+        return AudioFormat.CHANNEL_OUT_5POINT1 | AudioFormat.CHANNEL_OUT_BACK_CENTER;
+      case 8:
+        if (Util.SDK_INT >= 23) {
+          return AudioFormat.CHANNEL_OUT_7POINT1_SURROUND;
+        } else if (Util.SDK_INT >= 21) {
+          // Equal to AudioFormat.CHANNEL_OUT_7POINT1_SURROUND, which is hidden before Android M.
+          return AudioFormat.CHANNEL_OUT_5POINT1
+              | AudioFormat.CHANNEL_OUT_SIDE_LEFT
+              | AudioFormat.CHANNEL_OUT_SIDE_RIGHT;
+        } else {
+          // 8 ch output is not supported before Android L.
+          return AudioFormat.CHANNEL_INVALID;
+        }
+      default:
+        return AudioFormat.CHANNEL_INVALID;
+    }
+  }
+
+  /**
    * Returns the frame size for audio with {@code channelCount} channels in the specified encoding.
    * Returns the frame size for audio with {@code channelCount} channels in the specified encoding.
    *
    *
    * @param pcmEncoding The encoding of the audio data.
    * @param pcmEncoding The encoding of the audio data.