Parse Projection, ProjectionPrivate

As described in https://github.com/google/spatial-media/blob/master/docs/spherical-video-v2-rfc.md.
Also parse StereoMode as per standard matroska spec.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=134302208

library/src/main/java/com/google/android/exoplayer2/extractor/mkv/MatroskaExtractor.java

@@ -163,6 +163,9 @@ public final class MatroskaExtractor implements Extractor {
   private static final int ID_CUE_TRACK_POSITIONS = 0xB7;
   private static final int ID_CUE_TRACK_POSITIONS = 0xB7;
   private static final int ID_CUE_CLUSTER_POSITION = 0xF1;
   private static final int ID_CUE_CLUSTER_POSITION = 0xF1;
   private static final int ID_LANGUAGE = 0x22B59C;
   private static final int ID_LANGUAGE = 0x22B59C;
+  private static final int ID_PROJECTION = 0x7670;
+  private static final int ID_PROJECTION_PRIVATE = 0x7672;
+  private static final int ID_STEREO_MODE = 0x53B8;
 
 
   private static final int LACING_NONE = 0;
   private static final int LACING_NONE = 0;
   private static final int LACING_XIPH = 1;
   private static final int LACING_XIPH = 1;
@@ -362,6 +365,7 @@ public final class MatroskaExtractor implements Extractor {
       case ID_CUE_POINT:
       case ID_CUE_POINT:
       case ID_CUE_TRACK_POSITIONS:
       case ID_CUE_TRACK_POSITIONS:
       case ID_BLOCK_GROUP:
       case ID_BLOCK_GROUP:
+      case ID_PROJECTION:
         return EbmlReader.TYPE_MASTER;
         return EbmlReader.TYPE_MASTER;
       case ID_EBML_READ_VERSION:
       case ID_EBML_READ_VERSION:
       case ID_DOC_TYPE_READ_VERSION:
       case ID_DOC_TYPE_READ_VERSION:
@@ -391,6 +395,7 @@ public final class MatroskaExtractor implements Extractor {
       case ID_CUE_TIME:
       case ID_CUE_TIME:
       case ID_CUE_CLUSTER_POSITION:
       case ID_CUE_CLUSTER_POSITION:
       case ID_REFERENCE_BLOCK:
       case ID_REFERENCE_BLOCK:
+      case ID_STEREO_MODE:
         return EbmlReader.TYPE_UNSIGNED_INT;
         return EbmlReader.TYPE_UNSIGNED_INT;
       case ID_DOC_TYPE:
       case ID_DOC_TYPE:
       case ID_CODEC_ID:
       case ID_CODEC_ID:
@@ -402,6 +407,7 @@ public final class MatroskaExtractor implements Extractor {
       case ID_SIMPLE_BLOCK:
       case ID_SIMPLE_BLOCK:
       case ID_BLOCK:
       case ID_BLOCK:
       case ID_CODEC_PRIVATE:
       case ID_CODEC_PRIVATE:
+      case ID_PROJECTION_PRIVATE:
         return EbmlReader.TYPE_BINARY;
         return EbmlReader.TYPE_BINARY;
       case ID_DURATION:
       case ID_DURATION:
       case ID_SAMPLING_FREQUENCY:
       case ID_SAMPLING_FREQUENCY:
@@ -656,6 +662,22 @@ public final class MatroskaExtractor implements Extractor {
       case ID_BLOCK_DURATION:
       case ID_BLOCK_DURATION:
         blockDurationUs = scaleTimecodeToUs(value);
         blockDurationUs = scaleTimecodeToUs(value);
         return;
         return;
+      case ID_STEREO_MODE:
+        int layout = (int) value;
+        switch (layout) {
+          case 0:
+            currentTrack.stereoMode = C.STEREO_MODE_MONO;
+            break;
+          case 1:
+            currentTrack.stereoMode = C.STEREO_MODE_LEFT_RIGHT;
+            break;
+          case 3:
+            currentTrack.stereoMode = C.STEREO_MODE_TOP_BOTTOM;
+            break;
+          default:
+            break;
+        }
+        return;
       default:
       default:
         return;
         return;
     }
     }
@@ -706,6 +728,10 @@ public final class MatroskaExtractor implements Extractor {
         currentTrack.codecPrivate = new byte[contentSize];
         currentTrack.codecPrivate = new byte[contentSize];
         input.readFully(currentTrack.codecPrivate, 0, contentSize);
         input.readFully(currentTrack.codecPrivate, 0, contentSize);
         return;
         return;
+      case ID_PROJECTION_PRIVATE:
+        currentTrack.projectionData = new byte[contentSize];
+        input.readFully(currentTrack.projectionData, 0, contentSize);
+        return;
       case ID_CONTENT_COMPRESSION_SETTINGS:
       case ID_CONTENT_COMPRESSION_SETTINGS:
         // This extractor only supports header stripping, so the payload is the stripped bytes.
         // This extractor only supports header stripping, so the payload is the stripped bytes.
         currentTrack.sampleStrippedBytes = new byte[contentSize];
         currentTrack.sampleStrippedBytes = new byte[contentSize];
@@ -1292,6 +1318,9 @@ public final class MatroskaExtractor implements Extractor {
     public int displayWidth = Format.NO_VALUE;
     public int displayWidth = Format.NO_VALUE;
     public int displayHeight = Format.NO_VALUE;
     public int displayHeight = Format.NO_VALUE;
     public int displayUnit = DISPLAY_UNIT_PIXELS;
     public int displayUnit = DISPLAY_UNIT_PIXELS;
+    public byte[] projectionData = null;
+    @C.StereoMode
+    public int stereoMode = Format.NO_VALUE;
 
 
     // Audio elements. Initially set to their default values.
     // Audio elements. Initially set to their default values.
     public int channelCount = 1;
     public int channelCount = 1;
@@ -1450,7 +1479,7 @@ public final class MatroskaExtractor implements Extractor {
         }
         }
         format = Format.createVideoSampleFormat(Integer.toString(trackId), mimeType, null,
         format = Format.createVideoSampleFormat(Integer.toString(trackId), mimeType, null,
             Format.NO_VALUE, maxInputSize, width, height, Format.NO_VALUE, initializationData,
             Format.NO_VALUE, maxInputSize, width, height, Format.NO_VALUE, initializationData,
-            Format.NO_VALUE, pixelWidthHeightRatio, drmInitData);
+            Format.NO_VALUE, pixelWidthHeightRatio, projectionData, stereoMode, drmInitData);
       } else if (MimeTypes.APPLICATION_SUBRIP.equals(mimeType)) {
       } else if (MimeTypes.APPLICATION_SUBRIP.equals(mimeType)) {
         format = Format.createTextSampleFormat(Integer.toString(trackId), mimeType, null,
         format = Format.createTextSampleFormat(Integer.toString(trackId), mimeType, null,
             Format.NO_VALUE, selectionFlags, language, drmInitData);
             Format.NO_VALUE, selectionFlags, language, drmInitData);