Remapped MP4x to video/mp4x

library/extractor/src/main/java/com/google/android/exoplayer2/extractor/avi/StreamHeaderBox.java

@@ -25,8 +25,10 @@ public class StreamHeaderBox extends ResidentBox {
     final String mimeType = MimeTypes.VIDEO_MP4V;
     //final String mimeType = MimeTypes.VIDEO_H263;
 
-    //Doesn't seem to be supported on Android
-    STREAM_MAP.put('M' | ('P' << 8) | ('4' << 16) | ('2' << 24), MimeTypes.VIDEO_AVI);
+    //I've never seen an Android devices that actually supports MP42
+    STREAM_MAP.put('M' | ('P' << 8) | ('4' << 16) | ('2' << 24), MimeTypes.BASE_TYPE_VIDEO+"/mp42");
+    //Samsung seems to support the rare MP43.
+    STREAM_MAP.put('M' | ('P' << 8) | ('4' << 16) | ('3' << 24), MimeTypes.BASE_TYPE_VIDEO+"/mp43");
     STREAM_MAP.put('H' | ('2' << 8) | ('6' << 16) | ('4' << 24), MimeTypes.VIDEO_H264);
     STREAM_MAP.put('a' | ('v' << 8) | ('c' << 16) | ('1' << 24), MimeTypes.VIDEO_H264);
     STREAM_MAP.put('A' | ('V' << 8) | ('C' << 16) | ('1' << 24), MimeTypes.VIDEO_H264);