stagefright: Fix seeking in MPEG4 container - do not merge

- seek based on user-visible timestamp
- seek to previous, next and closest exactly
- also update OggExtractor seek to same logic

Bug: 12786906
Change-Id: I2d5e1fbff6469b6f081a284be2222a4cb50aa754

1 files changed, 9 insertions, 5 deletions

diff --git a/media/libstagefright/OggExtractor.cpp b/media/libstagefright/OggExtractor.cpp
index f3eeb03..1965ef9 100644
--- a/media/libstagefright/OggExtractor.cpp
+++ b/media/libstagefright/OggExtractor.cpp
@@ -320,22 +320,26 @@ status_t MyVorbisExtractor::seekToTime(int64_t timeUs) {
     }
 
     size_t left = 0;
-    size_t right = mTableOfContents.size();
-    while (left < right) {
-        size_t center = left / 2 + right / 2 + (left & right & 1);
+    size_t right_plus_one = mTableOfContents.size();
+    while (left < right_plus_one) {
+        size_t center = left + (right_plus_one - left) / 2;
 
         const TOCEntry &entry = mTableOfContents.itemAt(center);
 
         if (timeUs < entry.mTimeUs) {
-            right = center;
+            right_plus_one = center;
         } else if (timeUs > entry.mTimeUs) {
             left = center + 1;
         } else {
-            left = right = center;
+            left = center;
             break;
         }
     }
 
+    if (left == mTableOfContents.size()) {
+        --left;
+    }
+
     const TOCEntry &entry = mTableOfContents.itemAt(left);
 
     ALOGV("seeking to entry %d / %d at offset %lld",