Add docs, releaseOutputBufferAtTime, seekTo.

Change-Id: Iadd231b63e75b7937c13d2ebfef47aedeaeef5a1
diff --git a/include/ndk/NdkMediaExtractor.h b/include/ndk/NdkMediaExtractor.h
index 2ba69fb..5a319d7 100644
--- a/include/ndk/NdkMediaExtractor.h
+++ b/include/ndk/NdkMediaExtractor.h
@@ -114,6 +114,16 @@
  */
 bool AMediaExtractor_advance(AMediaExtractor*);
 
+typedef enum {
+    AMEDIAEXTRACTOR_SEEK_PREVIOUS_SYNC,
+    AMEDIAEXTRACTOR_SEEK_NEXT_SYNC,
+    AMEDIAEXTRACTOR_SEEK_CLOSEST_SYNC
+} SeekMode;
+
+/**
+ *
+ */
+media_status_t AMediaExtractor_seekTo(AMediaExtractor*, int64_t seekPosUs, SeekMode mode);
 
 /**
  * mapping of crypto scheme uuid to the scheme specific data for that scheme
@@ -146,7 +156,6 @@
     AMEDIAEXTRACTOR_SAMPLE_FLAG_ENCRYPTED = 2,
 };
 
-
 #ifdef __cplusplus
 } // extern "C"
 #endif