Add support for big endian 24/32-bit PCM

Also parse the PCM encoding for lpcm in MP4, and update `MatroskaExtractor`
similarly.

Tested manually in the demo app using an MP4 with 24-bit big endian audio.

PiperOrigin-RevId: 546878505

RELEASENOTES.md

@@ -50,6 +50,8 @@
         implementation details of an `Extractor` you must first call
         `Extractor.getUnderlyingInstance`.
 *   Audio:
+    *   Add support for 24/32-bit big endian PCM in MP4 and Matroska, and parse
+        PCM encoding for `lpcm` in MP4.
 *   Audio Offload:
     *   Add `AudioSink.getFormatOffloadSupport(Format)` that retrieves level of
         offload support the sink can provide for the format through a

libraries/common/src/main/java/androidx/media3/common/C.java

@@ -166,10 +166,12 @@ public final class C {
   /**
    * Represents an audio encoding, or an invalid or unset value. One of {@link Format#NO_VALUE},
    * {@link #ENCODING_INVALID}, {@link #ENCODING_PCM_8BIT}, {@link #ENCODING_PCM_16BIT}, {@link
-   * #ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_24BIT}, {@link #ENCODING_PCM_32BIT},
+   * #ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_24BIT}, {@link
-   * {@link #ENCODING_PCM_FLOAT}, {@link #ENCODING_MP3}, {@link #ENCODING_AC3}, {@link
+   * #ENCODING_PCM_24BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_32BIT}, {@link
-   * #ENCODING_E_AC3}, {@link #ENCODING_E_AC3_JOC}, {@link #ENCODING_AC4}, {@link #ENCODING_DTS},
+   * #ENCODING_PCM_32BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_FLOAT}, {@link #ENCODING_MP3}, {@link
-   * {@link #ENCODING_DTS_HD}, {@link #ENCODING_DOLBY_TRUEHD} or {@link #ENCODING_OPUS}.
+   * #ENCODING_AC3}, {@link #ENCODING_E_AC3}, {@link #ENCODING_E_AC3_JOC}, {@link #ENCODING_AC4},
+   * {@link #ENCODING_DTS}, {@link #ENCODING_DTS_HD}, {@link #ENCODING_DOLBY_TRUEHD} or {@link
+   * #ENCODING_OPUS}.
    */
   @UnstableApi
   @Documented
@@ -182,7 +184,9 @@ public final class C {
     ENCODING_PCM_16BIT,
     ENCODING_PCM_16BIT_BIG_ENDIAN,
     ENCODING_PCM_24BIT,
+    ENCODING_PCM_24BIT_BIG_ENDIAN,
     ENCODING_PCM_32BIT,
+    ENCODING_PCM_32BIT_BIG_ENDIAN,
     ENCODING_PCM_FLOAT,
     ENCODING_MP3,
     ENCODING_AAC_LC,
@@ -206,8 +210,9 @@ public final class C {
   /**
    * Represents a PCM audio encoding, or an invalid or unset value. One of {@link Format#NO_VALUE},
    * {@link #ENCODING_INVALID}, {@link #ENCODING_PCM_8BIT}, {@link #ENCODING_PCM_16BIT}, {@link
-   * #ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_24BIT}, {@link #ENCODING_PCM_32BIT},
+   * #ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_24BIT}, {@link
-   * {@link #ENCODING_PCM_FLOAT}.
+   * #ENCODING_PCM_24BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_32BIT}, {@link
+   * #ENCODING_PCM_32BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_FLOAT}.
    */
   @UnstableApi
   @Documented
@@ -220,7 +225,9 @@ public final class C {
     ENCODING_PCM_16BIT,
     ENCODING_PCM_16BIT_BIG_ENDIAN,
     ENCODING_PCM_24BIT,
+    ENCODING_PCM_24BIT_BIG_ENDIAN,
     ENCODING_PCM_32BIT,
+    ENCODING_PCM_32BIT_BIG_ENDIAN,
     ENCODING_PCM_FLOAT
   })
   public @interface PcmEncoding {}
@@ -240,9 +247,15 @@ public final class C {
   /** PCM encoding with 24 bits per sample. */
   @UnstableApi public static final int ENCODING_PCM_24BIT = 0x20000000;
 
+  /** Like {@link #ENCODING_PCM_24BIT} but with the bytes in big endian order. */
+  @UnstableApi public static final int ENCODING_PCM_24BIT_BIG_ENDIAN = 0x50000000;
+
   /** PCM encoding with 32 bits per sample. */
   @UnstableApi public static final int ENCODING_PCM_32BIT = 0x30000000;
 
+  /** Like {@link #ENCODING_PCM_32BIT} but with the bytes in big endian order. */
+  @UnstableApi public static final int ENCODING_PCM_32BIT_BIG_ENDIAN = 0x60000000;
+
   /** See {@link AudioFormat#ENCODING_PCM_FLOAT}. */
   @UnstableApi public static final int ENCODING_PCM_FLOAT = AudioFormat.ENCODING_PCM_FLOAT;
 

libraries/common/src/main/java/androidx/media3/common/audio/ToInt16PcmAudioProcessor.java

@@ -31,7 +31,9 @@ import java.nio.ByteBuffer;
  *   <li>{@link C#ENCODING_PCM_16BIT} ({@link #isActive()} will return {@code false})
  *   <li>{@link C#ENCODING_PCM_16BIT_BIG_ENDIAN}
  *   <li>{@link C#ENCODING_PCM_24BIT}
+ *   <li>{@link C#ENCODING_PCM_24BIT_BIG_ENDIAN}
  *   <li>{@link C#ENCODING_PCM_32BIT}
+ *   <li>{@link C#ENCODING_PCM_32BIT_BIG_ENDIAN}
  *   <li>{@link C#ENCODING_PCM_FLOAT}
  * </ul>
  */
@@ -47,7 +49,9 @@ public final class ToInt16PcmAudioProcessor extends BaseAudioProcessor {
         && encoding != C.ENCODING_PCM_16BIT
         && encoding != C.ENCODING_PCM_16BIT_BIG_ENDIAN
         && encoding != C.ENCODING_PCM_24BIT
+        && encoding != C.ENCODING_PCM_24BIT_BIG_ENDIAN
         && encoding != C.ENCODING_PCM_32BIT
+        && encoding != C.ENCODING_PCM_32BIT_BIG_ENDIAN
         && encoding != C.ENCODING_PCM_FLOAT) {
       throw new UnhandledAudioFormatException(inputAudioFormat);
     }
@@ -72,9 +76,11 @@ public final class ToInt16PcmAudioProcessor extends BaseAudioProcessor {
         resampledSize = size;
         break;
       case C.ENCODING_PCM_24BIT:
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
         resampledSize = (size / 3) * 2;
         break;
       case C.ENCODING_PCM_32BIT:
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_FLOAT:
         resampledSize = size / 2;
         break;
@@ -109,6 +115,13 @@ public final class ToInt16PcmAudioProcessor extends BaseAudioProcessor {
           buffer.put(inputBuffer.get(i + 2));
         }
         break;
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
+        // 24 BE -> 16 bit resampling. Drop the least significant byte.
+        for (int i = position; i < limit; i += 3) {
+          buffer.put(inputBuffer.get(i + 1));
+          buffer.put(inputBuffer.get(i));
+        }
+        break;
       case C.ENCODING_PCM_32BIT:
         // 32 -> 16 bit resampling. Drop the two least significant bytes.
         for (int i = position; i < limit; i += 4) {
@@ -116,6 +129,13 @@ public final class ToInt16PcmAudioProcessor extends BaseAudioProcessor {
           buffer.put(inputBuffer.get(i + 3));
         }
         break;
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
+        // 32 BE -> 16 bit resampling. Drop the two least significant bytes.
+        for (int i = position; i < limit; i += 4) {
+          buffer.put(inputBuffer.get(i + 1));
+          buffer.put(inputBuffer.get(i));
+        }
+        break;
       case C.ENCODING_PCM_FLOAT:
         // 32 bit floating point -> 16 bit resampling. Floating point values are in the range
         // [-1.0, 1.0], so need to be scaled by Short.MAX_VALUE.

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

@@ -46,7 +46,8 @@ public final class MediaFormatUtil {
    *
    * <p>Equivalent to {@link MediaFormat#KEY_PCM_ENCODING}, except it allows additional values
    * defined by {@link C.PcmEncoding}, including {@link C#ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link
-   * C#ENCODING_PCM_24BIT}, and {@link C#ENCODING_PCM_32BIT}.
+   * C#ENCODING_PCM_24BIT}, {@link C#ENCODING_PCM_24BIT_BIG_ENDIAN}, {@link C#ENCODING_PCM_32BIT}
+   * and {@link C#ENCODING_PCM_32BIT_BIG_ENDIAN}.
    */
   // The constant value must not be changed, because it's also set by the framework MediaParser API.
   public static final String KEY_PCM_ENCODING_EXTENDED = "exo-pcm-encoding-int";
@@ -445,6 +446,8 @@ public final class MediaFormatUtil {
         break;
       case Format.NO_VALUE:
       case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
       default:
         // No matching value. Do nothing.
         return;

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

@@ -1863,7 +1863,9 @@ public final class Util {
         || encoding == C.ENCODING_PCM_16BIT
         || encoding == C.ENCODING_PCM_16BIT_BIG_ENDIAN
         || encoding == C.ENCODING_PCM_24BIT
+        || encoding == C.ENCODING_PCM_24BIT_BIG_ENDIAN
         || encoding == C.ENCODING_PCM_32BIT
+        || encoding == C.ENCODING_PCM_32BIT_BIG_ENDIAN
         || encoding == C.ENCODING_PCM_FLOAT;
   }
 
@@ -1876,7 +1878,9 @@ public final class Util {
   @UnstableApi
   public static boolean isEncodingHighResolutionPcm(@C.PcmEncoding int encoding) {
     return encoding == C.ENCODING_PCM_24BIT
+        || encoding == C.ENCODING_PCM_24BIT_BIG_ENDIAN
         || encoding == C.ENCODING_PCM_32BIT
+        || encoding == C.ENCODING_PCM_32BIT_BIG_ENDIAN
         || encoding == C.ENCODING_PCM_FLOAT;
   }
 
@@ -1992,8 +1996,10 @@ public final class Util {
       case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
         return channelCount * 2;
       case C.ENCODING_PCM_24BIT:
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
         return channelCount * 3;
       case C.ENCODING_PCM_32BIT:
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_FLOAT:
         return channelCount * 4;
       case C.ENCODING_INVALID:

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

@@ -1726,7 +1726,9 @@ public final class DefaultAudioSink implements AudioSink {
       case C.ENCODING_PCM_16BIT:
       case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_24BIT:
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_32BIT:
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_8BIT:
       case C.ENCODING_PCM_FLOAT:
       case C.ENCODING_AAC_ER_BSAC:

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

@@ -282,7 +282,9 @@ public class DefaultAudioTrackBufferSizeProvider
       case C.ENCODING_PCM_16BIT:
       case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_24BIT:
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_32BIT:
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
       case C.ENCODING_PCM_8BIT:
       case C.ENCODING_PCM_FLOAT:
       case C.ENCODING_AAC_ER_BSAC:

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

@@ -29,7 +29,9 @@ import java.nio.ByteBuffer;
  *
  * <ul>
  *   <li>{@link C#ENCODING_PCM_24BIT}
+ *   <li>{@link C#ENCODING_PCM_24BIT_BIG_ENDIAN}
  *   <li>{@link C#ENCODING_PCM_32BIT}
+ *   <li>{@link C#ENCODING_PCM_32BIT_BIG_ENDIAN}
  *   <li>{@link C#ENCODING_PCM_FLOAT} ({@link #isActive()} will return {@code false})
  * </ul>
  */
@@ -70,6 +72,16 @@ import java.nio.ByteBuffer;
           writePcm32BitFloat(pcm32BitInteger, buffer);
         }
         break;
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
+        buffer = replaceOutputBuffer((size / 3) * 4);
+        for (int i = position; i < limit; i += 3) {
+          int pcm32BitInteger =
+              ((inputBuffer.get(i + 2) & 0xFF) << 8)
+                  | ((inputBuffer.get(i + 1) & 0xFF) << 16)
+                  | ((inputBuffer.get(i) & 0xFF) << 24);
+          writePcm32BitFloat(pcm32BitInteger, buffer);
+        }
+        break;
       case C.ENCODING_PCM_32BIT:
         buffer = replaceOutputBuffer(size);
         for (int i = position; i < limit; i += 4) {
@@ -81,6 +93,17 @@ import java.nio.ByteBuffer;
           writePcm32BitFloat(pcm32BitInteger, buffer);
         }
         break;
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
+        buffer = replaceOutputBuffer(size);
+        for (int i = position; i < limit; i += 4) {
+          int pcm32BitInteger =
+              (inputBuffer.get(i + 3) & 0xFF)
+                  | ((inputBuffer.get(i + 2) & 0xFF) << 8)
+                  | ((inputBuffer.get(i + 1) & 0xFF) << 16)
+                  | ((inputBuffer.get(i) & 0xFF) << 24);
+          writePcm32BitFloat(pcm32BitInteger, buffer);
+        }
+        break;
       case C.ENCODING_PCM_8BIT:
       case C.ENCODING_PCM_16BIT:
       case C.ENCODING_PCM_16BIT_BIG_ENDIAN:

libraries/extractor/src/main/java/androidx/media3/extractor/WavUtil.java

@@ -77,7 +77,10 @@ public final class WavUtil {
         return TYPE_PCM;
       case C.ENCODING_PCM_FLOAT:
         return TYPE_FLOAT;
-      case C.ENCODING_PCM_16BIT_BIG_ENDIAN: // Not TYPE_PCM, because TYPE_PCM is little endian.
+        // TYPE_PCM is little endian so big endian formats don't match.
+      case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
+      case C.ENCODING_PCM_24BIT_BIG_ENDIAN:
+      case C.ENCODING_PCM_32BIT_BIG_ENDIAN:
       case C.ENCODING_INVALID:
       case Format.NO_VALUE:
       default:

libraries/extractor/src/main/java/androidx/media3/extractor/mkv/MatroskaExtractor.java

@@ -2204,6 +2204,10 @@ public class MatroskaExtractor implements Extractor {
             pcmEncoding = C.ENCODING_PCM_8BIT;
           } else if (audioBitDepth == 16) {
             pcmEncoding = C.ENCODING_PCM_16BIT_BIG_ENDIAN;
+          } else if (audioBitDepth == 24) {
+            pcmEncoding = C.ENCODING_PCM_24BIT_BIG_ENDIAN;
+          } else if (audioBitDepth == 32) {
+            pcmEncoding = C.ENCODING_PCM_32BIT_BIG_ENDIAN;
           } else {
             pcmEncoding = Format.NO_VALUE;
             mimeType = MimeTypes.AUDIO_UNKNOWN;

libraries/extractor/src/main/java/androidx/media3/extractor/mp4/AtomParsers.java

@@ -1493,9 +1493,25 @@ import java.util.List;
       sampleRate = (int) Math.round(parent.readDouble());
       channelCount = parent.readUnsignedIntToInt();
 
-      // Skip always7F000000, sampleSize, formatSpecificFlags, constBytesPerAudioPacket,
+      parent.skipBytes(4); // always7F000000
-      // constLPCMFramesPerAudioPacket.
+      int bitsPerSample = parent.readUnsignedIntToInt();
-      parent.skipBytes(20);
+      int formatSpecificFlags = parent.readUnsignedIntToInt();
+      boolean isFloat = (formatSpecificFlags & 1) != 0;
+      boolean isBigEndian = (formatSpecificFlags & (1 << 1)) != 0;
+      if (!isFloat) {
+        if (bitsPerSample == 8) {
+          pcmEncoding = C.ENCODING_PCM_8BIT;
+        } else if (bitsPerSample == 16) {
+          pcmEncoding = isBigEndian ? C.ENCODING_PCM_16BIT_BIG_ENDIAN : C.ENCODING_PCM_16BIT;
+        } else if (bitsPerSample == 24) {
+          pcmEncoding = isBigEndian ? C.ENCODING_PCM_24BIT_BIG_ENDIAN : C.ENCODING_PCM_24BIT;
+        } else if (bitsPerSample == 32) {
+          pcmEncoding = isBigEndian ? C.ENCODING_PCM_32BIT_BIG_ENDIAN : C.ENCODING_PCM_32BIT;
+        }
+      } else if (bitsPerSample == 32) {
+        pcmEncoding = C.ENCODING_PCM_FLOAT;
+      }
+      parent.skipBytes(8); // constBytesPerAudioPacket, constLPCMFramesPerAudioPacket
     } else {
       // Unsupported version.
       return;
@@ -1541,12 +1557,17 @@ import java.util.List;
       mimeType = MimeTypes.AUDIO_AMR_NB;
     } else if (atomType == Atom.TYPE_sawb) {
       mimeType = MimeTypes.AUDIO_AMR_WB;
-    } else if (atomType == Atom.TYPE_lpcm || atomType == Atom.TYPE_sowt) {
+    } else if (atomType == Atom.TYPE_sowt) {
       mimeType = MimeTypes.AUDIO_RAW;
       pcmEncoding = C.ENCODING_PCM_16BIT;
     } else if (atomType == Atom.TYPE_twos) {
       mimeType = MimeTypes.AUDIO_RAW;
       pcmEncoding = C.ENCODING_PCM_16BIT_BIG_ENDIAN;
+    } else if (atomType == Atom.TYPE_lpcm) {
+      mimeType = MimeTypes.AUDIO_RAW;
+      if (pcmEncoding == Format.NO_VALUE) {
+        pcmEncoding = C.ENCODING_PCM_16BIT;
+      }
     } else if (atomType == Atom.TYPE__mp2 || atomType == Atom.TYPE__mp3) {
       mimeType = MimeTypes.AUDIO_MPEG;
     } else if (atomType == Atom.TYPE_mha1) {