muxer: Add support to force Cluster placement.

Change-Id: I7d4653561ca760885ba6926825ba6b80cdbea8ab

mkvmuxer.cpp

@@ -1461,6 +1461,7 @@ Segment::Segment()
       cluster_list_capacity_(0),
       cluster_list_size_(0),
       cues_track_(0),
+      force_new_cluster_(false),
       frames_(NULL),
       frames_capacity_(0),
       frames_size_(0),
@@ -1695,7 +1696,7 @@ bool Segment::AddFrame(const uint8* frame,
   // If the segment has a video track hold onto audio frames to make sure the
   // audio that is associated with the start time of a video key-frame is
   // muxed into the same cluster.
-  if (has_video_ && tracks_.TrackIsAudio(track_number)) {
+  if (has_video_ && tracks_.TrackIsAudio(track_number) && !force_new_cluster_) {
     Frame* const new_frame = new Frame();
     if (!new_frame->Init(frame, length))
       return false;
@@ -1875,6 +1876,10 @@ bool Segment::CuesTrack(uint64 track_number) {
   return true;
 }
 
+void Segment::ForceNewClusterOnNextFrame() {
+  force_new_cluster_ = true;
+}
+
 Track* Segment::GetTrackByNumber(uint64 track_number) const {
   return tracks_.GetTrackByNumber(track_number);
 }
@@ -1938,6 +1943,9 @@ bool Segment::WriteSegmentHeader() {
 int Segment::TestFrame(uint64 track_number,
                        uint64 frame_timestamp_ns,
                        bool is_key) const {
+  if (force_new_cluster_)
+    return 1;
+
   // If no clusters have been created yet, then create a new cluster
   // and write this frame immediately, in the new cluster.  This path
   // should only be followed once, the first time we attempt to write
@@ -2090,6 +2098,9 @@ bool Segment::DoNewClusterProcessing(uint64 track_number,
     if (result < 0)  // error
       return false;
 
+  // Always set force_new_cluster_ to false after TestFrame.
+  force_new_cluster_ = false;
+
   // A non-zero result means create a new cluster.
   if (result > 0 && !MakeNewCluster(frame_timestamp_ns))
     return false;

mkvmuxer.hpp

@@ -751,6 +751,10 @@ class Segment {
   // returned by the Add track functions.
   bool CuesTrack(uint64 track_number);
 
+  // This will force the muxer to create a new Cluster when the next frame is
+  // added.
+  void ForceNewClusterOnNextFrame();
+
   // Writes out any frames that have not been written out. Finalizes the last
   // cluster. May update the size and duration of the segment. May output the
   // Cues element. May finalize the SeekHead element. Returns true on success.
@@ -889,6 +893,9 @@ class Segment {
   // Track number that is associated with the cues element for this segment.
   uint64 cues_track_;
 
+  // Tells the muxer to force a new cluster on the next Block.
+  bool force_new_cluster_;
+
   // List of stored audio frames. These variables are used to store frames so
   // the muxer can follow the guideline "Audio blocks that contain the video
   // key frame's timecode should be in the same cluster as the video key frame

mkvmuxerutil.cpp

@@ -497,7 +497,7 @@ uint64 WriteVoidElement(IMkvWriter* writer, uint64 size) {
 void GetVersion(int32* major, int32* minor, int32* build, int32* revision) {
   *major = 0;
   *minor = 2;
-  *build = 0;
+  *build = 1;
   *revision = 0;
 }