Try input format PCM encoding first in MediaCodecAudioRenderer

...and remove hard requirement for 16-bit PCM support in the audio
sink even if that's not needed to playback.

If the audio file is using 24-bit or 32-bit (int) PCM,
MediaCodecAudioRenderer tries to output float, and if that is not
supported, falls back to 16-bit PCM. This commit changes this
behavior to first trying the media file format, then any close
high-resolution audio formats (such as float) and then fall back
to 16-bit PCM. The behaviour with DefaultAudioSink does not change,
but if an audio sink supports any more optimal formats, they will
now be used with MediaCodecAudioRenderer.

Issue: #1931

Author: nift4

libraries/common/src/main/java/androidx/media3/common/util/Util.java

@@ -2276,6 +2276,52 @@ public static boolean isEncodingHighResolutionPcm(@C.PcmEncoding int encoding) {
         || encoding == C.ENCODING_PCM_FLOAT;
   }
 
+  /**
+   * Returns the closest platform PCM encodings supported on the current API level for
+   * {@code encoding}. The results never include 16-bit PCM, which should be used if none of the
+   * suggested formats can be used for playback.
+   *
+   * @param encoding The encoding of the audio data.
+   * @return The closest platform encodings, sorted by descending order of preference. May be empty.
+   */
+  @UnstableApi
+  public static int[] getClosestPlatformPcmEncodings(@C.PcmEncoding int encoding) {
+    switch (encoding) {
+      case C.ENCODING_PCM_FLOAT:
+        return Build.VERSION.SDK_INT >= 31
+            ? new int[] {
+              AudioFormat.ENCODING_PCM_FLOAT,
+              AudioFormat.ENCODING_PCM_32BIT,
+              AudioFormat.ENCODING_PCM_24BIT_PACKED
+            }
+            : new int[] {AudioFormat.ENCODING_PCM_FLOAT};
+      case C.ENCODING_PCM_32BIT:
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
+        return Build.VERSION.SDK_INT >= 31
+            ? new int[] {
+              AudioFormat.ENCODING_PCM_32BIT,
+              AudioFormat.ENCODING_PCM_FLOAT,
+              AudioFormat.ENCODING_PCM_24BIT_PACKED
+            }
+            : new int[] {AudioFormat.ENCODING_PCM_FLOAT};
+      case C.ENCODING_PCM_24BIT:
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
+        return Build.VERSION.SDK_INT >= 31
+            ? new int[] {
+              AudioFormat.ENCODING_PCM_24BIT_PACKED,
+              AudioFormat.ENCODING_PCM_32BIT,
+              AudioFormat.ENCODING_PCM_FLOAT
+            }
+            : new int[] {AudioFormat.ENCODING_PCM_FLOAT};
+      case C.ENCODING_PCM_8BIT:
+        return new int[] {AudioFormat.ENCODING_PCM_8BIT};
+      case C.ENCODING_PCM_16BIT:
+      case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
+      default:
+        return new int[] {};
+    }
+  }
+
   /**
    * Returns the audio track channel configuration for the given channel count, or {@link
    * AudioFormat#CHANNEL_INVALID} if output is not possible.

libraries/exoplayer/src/main/java/androidx/media3/exoplayer/audio/MediaCodecAudioRenderer.java

@@ -26,7 +26,6 @@
 import android.annotation.SuppressLint;
 import android.content.Context;
 import android.media.AudioDeviceInfo;
-import android.media.AudioFormat;
 import android.media.MediaCodec;
 import android.media.MediaCrypto;
 import android.media.MediaFormat;
@@ -338,14 +337,38 @@ public String getName() {
     }
     // If the input is PCM then it will be passed directly to the sink. Hence the sink must support
     // the input format directly.
-    if (MimeTypes.AUDIO_RAW.equals(format.sampleMimeType) && !audioSink.supportsFormat(format)) {
-      return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_SUBTYPE);
-    }
-    // For all other input formats, we expect the decoder to output 16-bit PCM.
-    if (!audioSink.supportsFormat(
-        Util.getPcmFormat(C.ENCODING_PCM_16BIT, format.channelCount, format.sampleRate))) {
-      return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_SUBTYPE);
+    if (MimeTypes.AUDIO_RAW.equals(format.sampleMimeType)) {
+      if (!audioSink.supportsFormat(format)) {
+        return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_SUBTYPE);
+      }
+    } else {
+      // For all other input formats, MediaCodec can do some conversions for us. Check if the sink
+      // supports any of the formats we can get out of MediaCodec.
+      boolean pcmEncodingSupported = false;
+      // On API levels before 24, any non-PCM input format is decoded to 16-bit PCM.
+      if (SDK_INT >= 24) {
+        int[] platformEncodings = Util.getClosestPlatformPcmEncodings(format.pcmEncoding);
+        for (int platformEncoding : platformEncodings) {
+          if (audioSink.getFormatSupport(
+                  Util.getPcmFormat(platformEncoding, format.channelCount, format.sampleRate))
+              == AudioSink.SINK_FORMAT_SUPPORTED_DIRECTLY) {
+            pcmEncodingSupported = true;
+            break;
+          }
+        }
+      }
+      // If none of the suggested encodings are supported, fall back to MediaCodec's default value
+      // of 16-bit PCM.
+      if (!pcmEncodingSupported
+          && audioSink.supportsFormat(
+              Util.getPcmFormat(C.ENCODING_PCM_16BIT, format.channelCount, format.sampleRate))) {
+        pcmEncodingSupported = true;
+      }
+      if (!pcmEncodingSupported) {
+        return RendererCapabilities.create(C.FORMAT_UNSUPPORTED_SUBTYPE);
+      }
     }
+
     List<MediaCodecInfo> decoderInfos =
         getDecoderInfos(mediaCodecSelector, format, /* requiresSecureDecoder= */ false, audioSink);
     if (decoderInfos.isEmpty()) {
@@ -1025,11 +1048,18 @@ protected MediaFormat getMediaFormat(
         mediaFormat.setInteger("ac4-is-sync", 1);
       }
     }
-    if (SDK_INT >= 24
-        && audioSink.getFormatSupport(
-                Util.getPcmFormat(C.ENCODING_PCM_FLOAT, format.channelCount, format.sampleRate))
+    if (SDK_INT >= 24) {
+      int[] platformEncodings = Util.getClosestPlatformPcmEncodings(format.pcmEncoding);
+      for (int platformEncoding : platformEncodings) {
+        if (audioSink.getFormatSupport(
+                Util.getPcmFormat(platformEncoding, format.channelCount, format.sampleRate))
             == AudioSink.SINK_FORMAT_SUPPORTED_DIRECTLY) {
-      mediaFormat.setInteger(MediaFormat.KEY_PCM_ENCODING, AudioFormat.ENCODING_PCM_FLOAT);
+          mediaFormat.setInteger(MediaFormat.KEY_PCM_ENCODING, platformEncoding);
+          break;
+        }
+      }
+      // If none of the suggested encodings are supported, fall back to MediaCodec's default value
+      // of 16-bit PCM.
     }
     if (SDK_INT >= 32) {
       mediaFormat.setInteger(MediaFormat.KEY_MAX_OUTPUT_CHANNEL_COUNT, 99);