Include channel count in capabilities check

Issue: #4690

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=220640737

RELEASENOTES.md

@@ -7,6 +7,8 @@
   here ([#2826](https://github.com/google/ExoPlayer/issues/2826)).
 * Add options for controlling audio track selections to `DefaultTrackSelector`
   ([#3314](https://github.com/google/ExoPlayer/issues/3314)).
+* Include channel count in audio capabilities check
+  ([#4690](https://github.com/google/ExoPlayer/issues/4690)).
 * Do not retry failed loads whose error is `FileNotFoundException`.
 
 ### 2.9.1 ###

extensions/ffmpeg/src/main/java/com/google/android/exoplayer2/ext/ffmpeg/FfmpegAudioRenderer.java

@@ -145,12 +145,13 @@ public final class FfmpegAudioRenderer extends SimpleDecoderAudioRenderer {
   }
 
   private boolean isOutputSupported(Format inputFormat) {
-    return shouldUseFloatOutput(inputFormat) || supportsOutputEncoding(C.ENCODING_PCM_16BIT);
+    return shouldUseFloatOutput(inputFormat)
+        || supportsOutput(inputFormat.channelCount, C.ENCODING_PCM_16BIT);
   }
 
   private boolean shouldUseFloatOutput(Format inputFormat) {
     Assertions.checkNotNull(inputFormat.sampleMimeType);
-    if (!enableFloatOutput || !supportsOutputEncoding(C.ENCODING_PCM_FLOAT)) {
+    if (!enableFloatOutput || !supportsOutput(inputFormat.channelCount, C.ENCODING_PCM_FLOAT)) {
       return false;
     }
     switch (inputFormat.sampleMimeType) {

extensions/flac/src/main/java/com/google/android/exoplayer2/ext/flac/LibflacAudioRenderer.java

@@ -53,7 +53,7 @@ public class LibflacAudioRenderer extends SimpleDecoderAudioRenderer {
     if (!FlacLibrary.isAvailable()
         || !MimeTypes.AUDIO_FLAC.equalsIgnoreCase(format.sampleMimeType)) {
       return FORMAT_UNSUPPORTED_TYPE;
-    } else if (!supportsOutputEncoding(C.ENCODING_PCM_16BIT)) {
+    } else if (!supportsOutput(format.channelCount, C.ENCODING_PCM_16BIT)) {
       return FORMAT_UNSUPPORTED_SUBTYPE;
     } else if (!supportsFormatDrm(drmSessionManager, format.drmInitData)) {
       return FORMAT_UNSUPPORTED_DRM;

extensions/opus/src/main/java/com/google/android/exoplayer2/ext/opus/LibopusAudioRenderer.java

@@ -78,7 +78,7 @@ public final class LibopusAudioRenderer extends SimpleDecoderAudioRenderer {
     if (!OpusLibrary.isAvailable()
         || !MimeTypes.AUDIO_OPUS.equalsIgnoreCase(format.sampleMimeType)) {
       return FORMAT_UNSUPPORTED_TYPE;
-    } else if (!supportsOutputEncoding(C.ENCODING_PCM_16BIT)) {
+    } else if (!supportsOutput(format.channelCount, C.ENCODING_PCM_16BIT)) {
       return FORMAT_UNSUPPORTED_SUBTYPE;
     } else if (!supportsFormatDrm(drmSessionManager, format.drmInitData)) {
       return FORMAT_UNSUPPORTED_DRM;

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

@@ -29,11 +29,11 @@ import java.util.Arrays;
 @TargetApi(21)
 public final class AudioCapabilities {
 
-  /**
-   * The minimum audio capabilities supported by all devices.
-   */
+  private static final int DEFAULT_MAX_CHANNEL_COUNT = 8;
+
+  /** The minimum audio capabilities supported by all devices. */
   public static final AudioCapabilities DEFAULT_AUDIO_CAPABILITIES =
-      new AudioCapabilities(new int[] {AudioFormat.ENCODING_PCM_16BIT}, 2);
+      new AudioCapabilities(new int[] {AudioFormat.ENCODING_PCM_16BIT}, DEFAULT_MAX_CHANNEL_COUNT);
 
   /**
    * Returns the current audio capabilities for the device.
@@ -52,8 +52,10 @@ public final class AudioCapabilities {
     if (intent == null || intent.getIntExtra(AudioManager.EXTRA_AUDIO_PLUG_STATE, 0) == 0) {
       return DEFAULT_AUDIO_CAPABILITIES;
     }
-    return new AudioCapabilities(intent.getIntArrayExtra(AudioManager.EXTRA_ENCODINGS),
-        intent.getIntExtra(AudioManager.EXTRA_MAX_CHANNEL_COUNT, 0));
+    return new AudioCapabilities(
+        intent.getIntArrayExtra(AudioManager.EXTRA_ENCODINGS),
+        intent.getIntExtra(
+            AudioManager.EXTRA_MAX_CHANNEL_COUNT, /* defaultValue= */ DEFAULT_MAX_CHANNEL_COUNT));
   }
 
   private final int[] supportedEncodings;

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

@@ -18,6 +18,7 @@ package com.google.android.exoplayer2.audio;
 import android.media.AudioTrack;
 import android.support.annotation.Nullable;
 import com.google.android.exoplayer2.C;
+import com.google.android.exoplayer2.Format;
 import com.google.android.exoplayer2.PlaybackParameters;
 import java.nio.ByteBuffer;
 
@@ -166,12 +167,13 @@ public interface AudioSink {
   void setListener(Listener listener);
 
   /**
-   * Returns whether it's possible to play audio in the specified encoding.
+   * Returns whether the sink supports the audio format.
    *
-   * @param encoding The audio encoding.
-   * @return Whether it's possible to play audio in the specified encoding.
+   * @param channelCount The number of channels, or {@link Format#NO_VALUE} if not known.
+   * @param encoding The audio encoding, or {@link Format#NO_VALUE} if not known.
+   * @return Whether the sink supports the audio format.
    */
-  boolean isEncodingSupported(@C.Encoding int encoding);
+  boolean supportsOutput(int channelCount, @C.Encoding int encoding);
 
   /**
    * Returns the playback position in the stream starting at zero, in microseconds, or

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

@@ -376,14 +376,18 @@ public final class DefaultAudioSink implements AudioSink {
   }
 
   @Override
-  public boolean isEncodingSupported(@C.Encoding int encoding) {
+  public boolean supportsOutput(int channelCount, @C.Encoding int encoding) {
     if (Util.isEncodingLinearPcm(encoding)) {
       // AudioTrack supports 16-bit integer PCM output in all platform API versions, and float
       // output from platform API version 21 only. Other integer PCM encodings are resampled by this
-      // sink to 16-bit PCM.
+      // sink to 16-bit PCM. We assume that the audio framework will downsample any number of
+      // channels to the output device's required number of channels.
       return encoding != C.ENCODING_PCM_FLOAT || Util.SDK_INT >= 21;
     } else {
-      return audioCapabilities != null && audioCapabilities.supportsEncoding(encoding);
+      return audioCapabilities != null
+          && audioCapabilities.supportsEncoding(encoding)
+          && (channelCount == Format.NO_VALUE
+              || channelCount <= audioCapabilities.getMaxChannelCount());
     }
   }
 
@@ -414,7 +418,7 @@ public final class DefaultAudioSink implements AudioSink {
     isInputPcm = Util.isEncodingLinearPcm(inputEncoding);
     shouldConvertHighResIntPcmToFloat =
         enableConvertHighResIntPcmToFloat
-            && isEncodingSupported(C.ENCODING_PCM_32BIT)
+            && supportsOutput(channelCount, C.ENCODING_PCM_32BIT)
             && Util.isEncodingHighResolutionIntegerPcm(inputEncoding);
     if (isInputPcm) {
       pcmFrameSize = Util.getPcmFrameSize(inputEncoding, channelCount);

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

@@ -271,12 +271,14 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
     }
     int tunnelingSupport = Util.SDK_INT >= 21 ? TUNNELING_SUPPORTED : TUNNELING_NOT_SUPPORTED;
     boolean supportsFormatDrm = supportsFormatDrm(drmSessionManager, format.drmInitData);
-    if (supportsFormatDrm && allowPassthrough(mimeType)
+    if (supportsFormatDrm
+        && allowPassthrough(format.channelCount, mimeType)
         && mediaCodecSelector.getPassthroughDecoderInfo() != null) {
       return ADAPTIVE_NOT_SEAMLESS | tunnelingSupport | FORMAT_HANDLED;
     }
-    if ((MimeTypes.AUDIO_RAW.equals(mimeType) && !audioSink.isEncodingSupported(format.pcmEncoding))
-        || !audioSink.isEncodingSupported(C.ENCODING_PCM_16BIT)) {
+    if ((MimeTypes.AUDIO_RAW.equals(mimeType)
+            && !audioSink.supportsOutput(format.channelCount, format.pcmEncoding))
+        || !audioSink.supportsOutput(format.channelCount, C.ENCODING_PCM_16BIT)) {
       // Assume the decoder outputs 16-bit PCM, unless the input is raw.
       return FORMAT_UNSUPPORTED_SUBTYPE;
     }
@@ -315,7 +317,7 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
   protected List<MediaCodecInfo> getDecoderInfos(
       MediaCodecSelector mediaCodecSelector, Format format, boolean requiresSecureDecoder)
       throws DecoderQueryException {
-    if (allowPassthrough(format.sampleMimeType)) {
+    if (allowPassthrough(format.channelCount, format.sampleMimeType)) {
       MediaCodecInfo passthroughDecoderInfo = mediaCodecSelector.getPassthroughDecoderInfo();
       if (passthroughDecoderInfo != null) {
         return Collections.singletonList(passthroughDecoderInfo);
@@ -329,12 +331,13 @@ public class MediaCodecAudioRenderer extends MediaCodecRenderer implements Media
    * This implementation returns true if the {@link AudioSink} indicates that encoded audio output
    * is supported.
    *
+   * @param channelCount The number of channels in the input media, or {@link Format#NO_VALUE} if
+   *     not known.
    * @param mimeType The type of input media.
    * @return Whether passthrough playback is supported.
    */
-  protected boolean allowPassthrough(String mimeType) {
-    @C.Encoding int encoding = MimeTypes.getEncoding(mimeType);
-    return encoding != C.ENCODING_INVALID && audioSink.isEncodingSupported(encoding);
+  protected boolean allowPassthrough(int channelCount, String mimeType) {
+    return audioSink.supportsOutput(channelCount, MimeTypes.getEncoding(mimeType));
   }
 
   @Override

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

@@ -249,13 +249,12 @@ public abstract class SimpleDecoderAudioRenderer extends BaseRenderer implements
       DrmSessionManager<ExoMediaCrypto> drmSessionManager, Format format);
 
   /**
-   * Returns whether the audio sink can accept audio in the specified encoding.
+   * Returns whether the sink supports the audio format.
    *
-   * @param encoding The audio encoding.
-   * @return Whether the audio sink can accept audio in the specified encoding.
+   * @see AudioSink#supportsOutput(int, int)
    */
-  protected final boolean supportsOutputEncoding(@C.Encoding int encoding) {
-    return audioSink.isEncodingSupported(encoding);
+  protected final boolean supportsOutput(int channelCount, @C.Encoding int encoding) {
+    return audioSink.supportsOutput(channelCount, encoding);
   }
 
   @Override