Seeking/duration in HLS content is based on the individual segments' duration

not target-duration.

Change-Id: I294097daa84c25e4084a6fc4ea80e39a543f3d10
related-to-bug: 4983285
diff --git a/media/libstagefright/httplive/LiveSession.cpp b/media/libstagefright/httplive/LiveSession.cpp
index 165683e..f1a2a60 100644
--- a/media/libstagefright/httplive/LiveSession.cpp
+++ b/media/libstagefright/httplive/LiveSession.cpp
@@ -408,13 +408,20 @@
         if (firstTime) {
             Mutex::Autolock autoLock(mLock);
 
-            int32_t targetDuration;
-            if (!mPlaylist->isComplete()
-                    || !mPlaylist->meta()->findInt32(
-                    "target-duration", &targetDuration)) {
+            if (!mPlaylist->isComplete()) {
                 mDurationUs = -1;
             } else {
-                mDurationUs = 1000000ll * targetDuration * mPlaylist->size();
+                mDurationUs = 0;
+                for (size_t i = 0; i < mPlaylist->size(); ++i) {
+                    sp<AMessage> itemMeta;
+                    CHECK(mPlaylist->itemAt(
+                                i, NULL /* uri */, &itemMeta));
+
+                    int64_t itemDurationUs;
+                    CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
+
+                    mDurationUs += itemDurationUs;
+                }
             }
         }
 
@@ -431,14 +438,26 @@
     bool bandwidthChanged = false;
 
     if (mSeekTimeUs >= 0) {
-        int32_t targetDuration;
-        if (mPlaylist->isComplete() &&
-                mPlaylist->meta()->findInt32(
-                    "target-duration", &targetDuration)) {
-            int64_t seekTimeSecs = (mSeekTimeUs + 500000ll) / 1000000ll;
-            int64_t index = seekTimeSecs / targetDuration;
+        if (mPlaylist->isComplete()) {
+            size_t index = 0;
+            int64_t segmentStartUs = 0;
+            while (index < mPlaylist->size()) {
+                sp<AMessage> itemMeta;
+                CHECK(mPlaylist->itemAt(
+                            index, NULL /* uri */, &itemMeta));
 
-            if (index >= 0 && index < mPlaylist->size()) {
+                int64_t itemDurationUs;
+                CHECK(itemMeta->findInt64("durationUs", &itemDurationUs));
+
+                if (mSeekTimeUs < segmentStartUs + itemDurationUs) {
+                    break;
+                }
+
+                segmentStartUs += itemDurationUs;
+                ++index;
+            }
+
+            if (index < mPlaylist->size()) {
                 int32_t newSeqNumber = firstSeqNumberInPlaylist + index;
 
                 if (newSeqNumber != mSeqNumber) {
diff --git a/media/libstagefright/httplive/M3UParser.cpp b/media/libstagefright/httplive/M3UParser.cpp
index 765f795..123fbf8 100644
--- a/media/libstagefright/httplive/M3UParser.cpp
+++ b/media/libstagefright/httplive/M3UParser.cpp
@@ -64,14 +64,21 @@
 }
 
 bool M3UParser::itemAt(size_t index, AString *uri, sp<AMessage> *meta) {
-    uri->clear();
-    if (meta) { *meta = NULL; }
+    if (uri) {
+        uri->clear();
+    }
+
+    if (meta) {
+        *meta = NULL;
+    }
 
     if (index >= mItems.size()) {
         return false;
     }
 
-    *uri = mItems.itemAt(index).mURI;
+    if (uri) {
+        *uri = mItems.itemAt(index).mURI;
+    }
 
     if (meta) {
         *meta = mItems.itemAt(index).mMeta;