1 files changed, 79 insertions, 5 deletions

diff --git a/media/libstagefright/httplive/LiveSession.h b/media/libstagefright/httplive/LiveSession.h
index 8f6a4ea..3f8fee5 100644
--- a/media/libstagefright/httplive/LiveSession.h
+++ b/media/libstagefright/httplive/LiveSession.h
@@ -42,10 +42,17 @@ struct LiveSession : public AHandler {
             const sp<AMessage> &notify,
             uint32_t flags = 0, bool uidValid = false, uid_t uid = 0);
 
+    enum StreamIndex {
+        kAudioIndex    = 0,
+        kVideoIndex    = 1,
+        kSubtitleIndex = 2,
+        kMaxStreams    = 3,
+    };
+
     enum StreamType {
-        STREAMTYPE_AUDIO        = 1,
-        STREAMTYPE_VIDEO        = 2,
-        STREAMTYPE_SUBTITLES    = 4,
+        STREAMTYPE_AUDIO        = 1 << kAudioIndex,
+        STREAMTYPE_VIDEO        = 1 << kVideoIndex,
+        STREAMTYPE_SUBTITLES    = 1 << kSubtitleIndex,
     };
     status_t dequeueAccessUnit(StreamType stream, sp<ABuffer> *accessUnit);
 
@@ -74,6 +81,11 @@ struct LiveSession : public AHandler {
         kWhatPreparationFailed,
     };
 
+    // create a format-change discontinuity
+    //
+    // swap:
+    //   whether is format-change discontinuity should trigger a buffer swap
+    sp<ABuffer> createFormatChangeBuffer(bool swap = true);
 protected:
     virtual ~LiveSession();
 
@@ -92,6 +104,7 @@ private:
         kWhatChangeConfiguration2       = 'chC2',
         kWhatChangeConfiguration3       = 'chC3',
         kWhatFinishDisconnect2          = 'fin2',
+        kWhatSwapped                    = 'swap',
     };
 
     struct BandwidthItem {
@@ -103,8 +116,22 @@ private:
         sp<PlaylistFetcher> mFetcher;
         int64_t mDurationUs;
         bool mIsPrepared;
+        bool mToBeRemoved;
     };
 
+    struct StreamItem {
+        const char *mType;
+        AString mUri;
+        StreamItem() : mType("") {}
+        StreamItem(const char *type) : mType(type) {}
+        AString uriKey() {
+            AString key(mType);
+            key.append("URI");
+            return key;
+        }
+    };
+    StreamItem mStreams[kMaxStreams];
+
     sp<AMessage> mNotify;
     uint32_t mFlags;
     bool mUIDValid;
@@ -123,21 +150,40 @@ private:
     sp<M3UParser> mPlaylist;
 
     KeyedVector<AString, FetcherInfo> mFetcherInfos;
-    AString mAudioURI, mVideoURI, mSubtitleURI;
     uint32_t mStreamMask;
 
+    // Masks used during reconfiguration:
+    // mNewStreamMask: streams in the variant playlist we're switching to;
+    // we don't want to immediately overwrite the original value.
+    uint32_t mNewStreamMask;
+
+    // mSwapMask: streams that have started to playback content in the new variant playlist;
+    // we use this to track reconfiguration progress.
+    uint32_t mSwapMask;
+
     KeyedVector<StreamType, sp<AnotherPacketSource> > mPacketSources;
+    // A second set of packet sources that buffer content for the variant we're switching to.
+    KeyedVector<StreamType, sp<AnotherPacketSource> > mPacketSources2;
+
+    // A mutex used to serialize two sets of events:
+    // * the swapping of packet sources in dequeueAccessUnit on the player thread, AND
+    // * a forced bandwidth switch termination in cancelSwitch on the live looper.
+    Mutex mSwapMutex;
 
     int32_t mCheckBandwidthGeneration;
+    int32_t mSwitchGeneration;
 
     size_t mContinuationCounter;
     sp<AMessage> mContinuation;
+    sp<AMessage> mSeekReply;
 
     int64_t mLastDequeuedTimeUs;
     int64_t mRealTimeBaseUs;
 
     bool mReconfigurationInProgress;
+    bool mSwitchInProgress;
     uint32_t mDisconnectReplyID;
+    uint32_t mSeekReplyID;
 
     sp<PlaylistFetcher> addFetcher(const char *uri);
 
@@ -145,9 +191,25 @@ private:
     status_t onSeek(const sp<AMessage> &msg);
     void onFinishDisconnect2();
 
-    status_t fetchFile(
+    // If given a non-zero block_size (default 0), it is used to cap the number of
+    // bytes read in from the DataSource. If given a non-NULL buffer, new content
+    // is read into the end.
+    //
+    // The DataSource we read from is responsible for signaling error or EOF to help us
+    // break out of the read loop. The DataSource can be returned to the caller, so
+    // that the caller can reuse it for subsequent fetches (within the initially
+    // requested range).
+    //
+    // For reused HTTP sources, the caller must download a file sequentially without
+    // any overlaps or gaps to prevent reconnection.
+    ssize_t fetchFile(
             const char *url, sp<ABuffer> *out,
+            /* request/open a file starting at range_offset for range_length bytes */
             int64_t range_offset = 0, int64_t range_length = -1,
+            /* download block size */
+            uint32_t block_size = 0,
+            /* reuse DataSource if doing partial fetch */
+            sp<DataSource> *source = NULL,
             String8 *actualUrl = NULL);
 
     sp<M3UParser> fetchPlaylist(
@@ -156,22 +218,34 @@ private:
     size_t getBandwidthIndex();
 
     static int SortByBandwidth(const BandwidthItem *, const BandwidthItem *);
+    static StreamType indexToType(int idx);
 
     void changeConfiguration(
             int64_t timeUs, size_t bandwidthIndex, bool pickTrack = false);
     void onChangeConfiguration(const sp<AMessage> &msg);
     void onChangeConfiguration2(const sp<AMessage> &msg);
     void onChangeConfiguration3(const sp<AMessage> &msg);
+    void onSwapped(const sp<AMessage> &msg);
+    void tryToFinishBandwidthSwitch();
 
     void scheduleCheckBandwidthEvent();
     void cancelCheckBandwidthEvent();
 
+    // cancelBandwidthSwitch is atomic wrt swapPacketSource; call it to prevent packet sources
+    // from being swapped out on stale discontinuities while manipulating
+    // mPacketSources/mPacketSources2.
+    void cancelBandwidthSwitch();
+
+    bool canSwitchBandwidthTo(size_t bandwidthIndex);
     void onCheckBandwidth();
 
     void finishDisconnect();
 
     void postPrepared(status_t err);
 
+    void swapPacketSource(StreamType stream);
+    bool canSwitchUp();
+
     DISALLOW_EVIL_CONSTRUCTORS(LiveSession);
 };