MPEG4Extractor: set mime type of fileMetaData correctly.

Bug: 32045229
Change-Id: Iaf165e4731296175d361e30597b03beaa1e6e833
diff --git a/media/libstagefright/MPEG4Extractor.cpp b/media/libstagefright/MPEG4Extractor.cpp
index 0ce7a5e..0395c77 100644
--- a/media/libstagefright/MPEG4Extractor.cpp
+++ b/media/libstagefright/MPEG4Extractor.cpp
@@ -374,7 +374,6 @@
       mMdatFound(false),
       mDataSource(source),
       mInitCheck(NO_INIT),
-      mHasVideo(false),
       mHeaderTimescale(0),
       mIsQT(false),
       mFirstTrack(NULL),
@@ -545,11 +544,13 @@
     }
 
     if (mInitCheck == OK) {
-        if (mHasVideo) {
+        if (findTrackByMimePrefix("video/") != NULL) {
             mFileMetaData->setCString(
                     kKeyMIMEType, MEDIA_MIMETYPE_CONTAINER_MPEG4);
-        } else {
+        } else if (findTrackByMimePrefix("audio/") != NULL) {
             mFileMetaData->setCString(kKeyMIMEType, "audio/mp4");
+        } else {
+            mFileMetaData->setCString(kKeyMIMEType, "application/octet-stream");
         }
     } else {
         mInitCheck = err;
@@ -1481,8 +1482,6 @@
         case FOURCC('h', 'v', 'c', '1'):
         case FOURCC('h', 'e', 'v', '1'):
         {
-            mHasVideo = true;
-
             uint8_t buffer[78];
             if (chunk_data_size < (ssize_t)sizeof(buffer)) {
                 // Basic VideoSampleEntry size.
diff --git a/media/libstagefright/include/MPEG4Extractor.h b/media/libstagefright/include/MPEG4Extractor.h
index 37c35e3..836cb08 100644
--- a/media/libstagefright/include/MPEG4Extractor.h
+++ b/media/libstagefright/include/MPEG4Extractor.h
@@ -93,7 +93,6 @@
 
     sp<DataSource> mDataSource;
     status_t mInitCheck;
-    bool mHasVideo;
     uint32_t mHeaderTimescale;
     bool mIsQT;