Support twos codec in MP4

Issue: #5789 PiperOrigin-RevId: 287828559
google · Jan 2, 2020 · f0e0ee4 · f0e0ee4
1 parent 2380f93
commit f0e0ee4
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Showing 6 changed files with 42 additions and 14 deletions.
diff --git a/RELEASENOTES.md b/RELEASENOTES.md
@@ -34,6 +34,8 @@
   to proceed.
 * Fix handling of E-AC-3 streams that contain AC-3 syncframes
   ([#6602](https://github.com/google/ExoPlayer/issues/6602)).
+* Support "twos" codec (big endian PCM) in MP4
+  ([#5789](https://github.com/google/ExoPlayer/issues/5789)).
 
 ### 2.11.1 (2019-12-20) ###
 

diff --git a/library/core/src/main/java/com/google/android/exoplayer2/C.java b/library/core/src/main/java/com/google/android/exoplayer2/C.java
@@ -150,10 +150,11 @@ private 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_24BIT}, {@link #ENCODING_PCM_32BIT}, {@link #ENCODING_PCM_FLOAT}, {@link
-   * #ENCODING_PCM_MU_LAW}, {@link #ENCODING_PCM_A_LAW}, {@link #ENCODING_MP3}, {@link
-   * #ENCODING_AC3}, {@link #ENCODING_E_AC3}, {@link #ENCODING_E_AC3_JOC}, {@link #ENCODING_AC4},
-   * {@link #ENCODING_DTS}, {@link #ENCODING_DTS_HD} or {@link #ENCODING_DOLBY_TRUEHD}.
+   * #ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_24BIT}, {@link #ENCODING_PCM_32BIT},
+   * {@link #ENCODING_PCM_FLOAT}, {@link #ENCODING_PCM_MU_LAW}, {@link #ENCODING_PCM_A_LAW}, {@link
+   * #ENCODING_MP3}, {@link #ENCODING_AC3}, {@link #ENCODING_E_AC3}, {@link #ENCODING_E_AC3_JOC},
+   * {@link #ENCODING_AC4}, {@link #ENCODING_DTS}, {@link #ENCODING_DTS_HD} or {@link
+   * #ENCODING_DOLBY_TRUEHD}.
    */
   @Documented
   @Retention(RetentionPolicy.SOURCE)
@@ -162,6 +163,7 @@ private C() {}
     ENCODING_INVALID,
     ENCODING_PCM_8BIT,
     ENCODING_PCM_16BIT,
+    ENCODING_PCM_16BIT_BIG_ENDIAN,
     ENCODING_PCM_24BIT,
     ENCODING_PCM_32BIT,
     ENCODING_PCM_FLOAT,
@@ -181,8 +183,8 @@ private 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_24BIT}, {@link #ENCODING_PCM_32BIT}, {@link #ENCODING_PCM_FLOAT}, {@link
-   * #ENCODING_PCM_MU_LAW} or {@link #ENCODING_PCM_A_LAW}.
+   * #ENCODING_PCM_16BIT_BIG_ENDIAN}, {@link #ENCODING_PCM_24BIT}, {@link #ENCODING_PCM_32BIT},
+   * {@link #ENCODING_PCM_FLOAT}, {@link #ENCODING_PCM_MU_LAW} or {@link #ENCODING_PCM_A_LAW}.
    */
   @Documented
   @Retention(RetentionPolicy.SOURCE)
@@ -191,6 +193,7 @@ private C() {}
     ENCODING_INVALID,
     ENCODING_PCM_8BIT,
     ENCODING_PCM_16BIT,
+    ENCODING_PCM_16BIT_BIG_ENDIAN,
     ENCODING_PCM_24BIT,
     ENCODING_PCM_32BIT,
     ENCODING_PCM_FLOAT,
@@ -204,6 +207,8 @@ private C() {}
   public static final int ENCODING_PCM_8BIT = AudioFormat.ENCODING_PCM_8BIT;
   /** @see AudioFormat#ENCODING_PCM_16BIT */
   public static final int ENCODING_PCM_16BIT = AudioFormat.ENCODING_PCM_16BIT;
+  /** Like {@link #ENCODING_PCM_16BIT}, but with the bytes in big endian order. */
+  public static final int ENCODING_PCM_16BIT_BIG_ENDIAN = 0x08000000;
   /** PCM encoding with 24 bits per sample. */
   public static final int ENCODING_PCM_24BIT = 0x80000000;
   /** PCM encoding with 32 bits per sample. */

diff --git a/library/core/src/main/java/com/google/android/exoplayer2/audio/ResamplingAudioProcessor.java b/library/core/src/main/java/com/google/android/exoplayer2/audio/ResamplingAudioProcessor.java
@@ -29,8 +29,11 @@
   public AudioFormat onConfigure(AudioFormat inputAudioFormat)
       throws UnhandledAudioFormatException {
     @C.PcmEncoding int encoding = inputAudioFormat.encoding;
-    if (encoding != C.ENCODING_PCM_8BIT && encoding != C.ENCODING_PCM_16BIT
-        && encoding != C.ENCODING_PCM_24BIT && encoding != C.ENCODING_PCM_32BIT) {
+    if (encoding != C.ENCODING_PCM_8BIT
+        && encoding != C.ENCODING_PCM_16BIT
+        && encoding != C.ENCODING_PCM_16BIT_BIG_ENDIAN
+        && encoding != C.ENCODING_PCM_24BIT
+        && encoding != C.ENCODING_PCM_32BIT) {
       throw new UnhandledAudioFormatException(inputAudioFormat);
     }
     return encoding != C.ENCODING_PCM_16BIT
@@ -50,6 +53,9 @@ public void queueInput(ByteBuffer inputBuffer) {
       case C.ENCODING_PCM_8BIT:
         resampledSize = size * 2;
         break;
+      case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
+        resampledSize = size;
+        break;
       case C.ENCODING_PCM_24BIT:
         resampledSize = (size / 3) * 2;
         break;
@@ -70,21 +76,28 @@ public void queueInput(ByteBuffer inputBuffer) {
     ByteBuffer buffer = replaceOutputBuffer(resampledSize);
     switch (inputAudioFormat.encoding) {
       case C.ENCODING_PCM_8BIT:
-        // 8->16 bit resampling. Shift each byte from [0, 256) to [-128, 128) and scale up.
+        // 8 -> 16 bit resampling. Shift each byte from [0, 256) to [-128, 128) and scale up.
         for (int i = position; i < limit; i++) {
           buffer.put((byte) 0);
           buffer.put((byte) ((inputBuffer.get(i) & 0xFF) - 128));
         }
         break;
+      case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
+        // Big endian to little endian resampling. Swap the byte order.
+        for (int i = position; i < limit; i += 2) {
+          buffer.put(inputBuffer.get(i + 1));
+          buffer.put(inputBuffer.get(i));
+        }
+        break;
       case C.ENCODING_PCM_24BIT:
-        // 24->16 bit resampling. Drop the least significant byte.
+        // 24 -> 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 + 2));
         }
         break;
       case C.ENCODING_PCM_32BIT:
-        // 32->16 bit resampling. Drop the two least significant bytes.
+        // 32 -> 16 bit resampling. Drop the two least significant bytes.
         for (int i = position; i < limit; i += 4) {
           buffer.put(inputBuffer.get(i + 2));
           buffer.put(inputBuffer.get(i + 3));

diff --git a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/Atom.java b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/Atom.java
@@ -379,6 +379,9 @@
   @SuppressWarnings("ConstantCaseForConstants")
   public static final int TYPE_dfLa = 0x64664c61;
 
+  @SuppressWarnings("ConstantCaseForConstants")
+  public static final int TYPE_twos = 0x74776f73;
+
   public final int type;
 
   public Atom(int type) {

diff --git a/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java b/library/core/src/main/java/com/google/android/exoplayer2/extractor/mp4/AtomParsers.java
@@ -798,6 +798,7 @@ private static StsdData parseStsd(
           || childAtomType == Atom.TYPE_sawb
           || childAtomType == Atom.TYPE_lpcm
           || childAtomType == Atom.TYPE_sowt
+          || childAtomType == Atom.TYPE_twos
           || childAtomType == Atom.TYPE__mp3
           || childAtomType == Atom.TYPE_alac
           || childAtomType == Atom.TYPE_alaw
@@ -1086,6 +1087,7 @@ private static void parseAudioSampleEntry(
 
     int channelCount;
     int sampleRate;
+    @C.PcmEncoding int pcmEncoding = Format.NO_VALUE;
 
     if (quickTimeSoundDescriptionVersion == 0 || quickTimeSoundDescriptionVersion == 1) {
       channelCount = parent.readUnsignedShort();
@@ -1147,6 +1149,10 @@ private static void parseAudioSampleEntry(
       mimeType = MimeTypes.AUDIO_AMR_WB;
     } else if (atomType == Atom.TYPE_lpcm || 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__mp3) {
       mimeType = MimeTypes.AUDIO_MPEG;
     } else if (atomType == Atom.TYPE_alac) {
@@ -1233,9 +1239,6 @@ private static void parseAudioSampleEntry(
     }
 
     if (out.format == null && mimeType != null) {
-      // TODO: Determine the correct PCM encoding.
-      @C.PcmEncoding int pcmEncoding =
-          MimeTypes.AUDIO_RAW.equals(mimeType) ? C.ENCODING_PCM_16BIT : Format.NO_VALUE;
       out.format = Format.createAudioSampleFormat(Integer.toString(trackId), mimeType, null,
           Format.NO_VALUE, Format.NO_VALUE, channelCount, sampleRate, pcmEncoding,
           initializationData == null ? null : Collections.singletonList(initializationData),

diff --git a/library/core/src/main/java/com/google/android/exoplayer2/util/Util.java b/library/core/src/main/java/com/google/android/exoplayer2/util/Util.java
@@ -1355,6 +1355,7 @@ public static int getPcmEncoding(int bitDepth) {
   public static boolean isEncodingLinearPcm(@C.Encoding int encoding) {
     return encoding == C.ENCODING_PCM_8BIT
         || encoding == C.ENCODING_PCM_16BIT
+        || encoding == C.ENCODING_PCM_16BIT_BIG_ENDIAN
         || encoding == C.ENCODING_PCM_24BIT
         || encoding == C.ENCODING_PCM_32BIT
         || encoding == C.ENCODING_PCM_FLOAT;
@@ -1423,6 +1424,7 @@ public static int getPcmFrameSize(@C.PcmEncoding int pcmEncoding, int channelCou
       case C.ENCODING_PCM_8BIT:
         return channelCount;
       case C.ENCODING_PCM_16BIT:
+      case C.ENCODING_PCM_16BIT_BIG_ENDIAN:
         return channelCount * 2;
       case C.ENCODING_PCM_24BIT:
         return channelCount * 3;