diff --git a/Timeline.cpp b/Timeline.cpp
new file mode 100644
index 0000000..cc1336c
--- /dev/null
+++ b/Timeline.cpp
@@ -0,0 +1,87 @@
+
+#include <algorithm>
+
+
+#include "defines.h"
+#include "Log.h"
+#include "Timeline.h"
+
+#define SEGMENT_ARRAY_MAX_SIZE 1000
+
+
+Timeline::Timeline() : array_(nullptr)
+{
+    reset();
+}
+
+Timeline::~Timeline()
+{
+    reset();
+}
+
+void Timeline::reset()
+{
+    start_ = GST_CLOCK_TIME_NONE;
+    end_ = GST_CLOCK_TIME_NONE;
+    num_frames_ = 0;
+    array_size_ = 0;
+    // clear segment array
+    if (array_ != nullptr)
+        free(array_);
+}
+
+void Timeline::init(GstClockTime start, GstClockTime end, GstClockTime frame_duration)
+{
+    reset();
+
+    start_ = start;
+    end_   = end;
+    num_frames_ = (size_t) end_ / (size_t) frame_duration;
+
+    array_size_ = MIN( SEGMENT_ARRAY_MAX_SIZE, num_frames_);
+    array_ = (float *) malloc(array_size_ * sizeof(float));
+    for (int i = 0; i < array_size_; ++i)
+        array_[i] = 1.f;
+
+    Log::Info("%d frames in timeline", array_size_);
+}
+
+bool Timeline::addPlaySegment(GstClockTime begin, GstClockTime end)
+{
+    return addPlaySegment( MediaSegment(begin, end) );
+}
+
+bool Timeline::addPlaySegment(MediaSegment s)
+{
+    if ( s.is_valid() )
+        return segments_.insert(s).second;
+
+    return false;
+}
+
+bool Timeline::removeAllPlaySegmentOverlap(MediaSegment s)
+{
+    bool ret = removePlaySegmentAt(s.begin);
+    return removePlaySegmentAt(s.end) || ret;
+}
+
+bool Timeline::removePlaySegmentAt(GstClockTime t)
+{
+    MediaSegmentSet::const_iterator s = std::find_if(segments_.begin(), segments_.end(), containsTime(t));
+
+    if ( s != segments_.end() ) {
+        segments_.erase(s);
+        return true;
+    }
+
+    return false;
+}
+
+std::list< std::pair<guint64, guint64> > Timeline::getPlaySegments() const
+{
+    std::list< std::pair<guint64, guint64> > ret;
+    for (MediaSegmentSet::iterator it = segments_.begin(); it != segments_.end(); it++)
+        ret.push_back( std::make_pair( it->begin, it->end ) );
+
+    return ret;
+}
diff --git a/Timeline.h b/Timeline.h
new file mode 100644
index 0000000..97ae369
--- /dev/null
+++ b/Timeline.h
@@ -0,0 +1,98 @@
+#ifndef TIMELINE_H
+#define TIMELINE_H
+
+#include <string>
+#include <sstream>
+#include <set>
+#include <list>
+
+#include <gst/pbutils/pbutils.h>
+
+struct MediaSegment
+{
+    GstClockTime begin;
+    GstClockTime end;
+
+    MediaSegment()
+    {
+        begin = GST_CLOCK_TIME_NONE;
+        end = GST_CLOCK_TIME_NONE;
+    }
+
+    MediaSegment(GstClockTime b, GstClockTime e)
+    {
+        if ( b < e ) {
+            begin = b;
+            end = e;
+        } else {
+            begin = GST_CLOCK_TIME_NONE;
+            end = GST_CLOCK_TIME_NONE;
+        }
+    }
+    inline bool is_valid() const
+    {
+        return begin != GST_CLOCK_TIME_NONE && end != GST_CLOCK_TIME_NONE && begin < end;
+    }
+    inline bool operator < (const MediaSegment b) const
+    {
+        return (this->is_valid() && b.is_valid() && this->end < b.begin);
+    }
+    inline bool operator == (const MediaSegment b) const
+    {
+        return (this->begin == b.begin && this->end == b.end);
+    }
+    inline bool operator != (const MediaSegment b) const
+    {
+        return (this->begin != b.begin || this->end != b.end);
+    }
+};
+
+struct containsTime: public std::unary_function<MediaSegment, bool>
+{
+    inline bool operator()(const MediaSegment s) const
+    {
+       return ( s.is_valid() && _t > s.begin && _t < s.end );
+    }
+
+    containsTime(GstClockTime t) : _t(t) { }
+
+private:
+    GstClockTime _t;
+};
+
+
+typedef std::set<MediaSegment> MediaSegmentSet;
+
+
+class Timeline
+{
+public:
+    Timeline();
+    ~Timeline();
+
+    void reset();
+    void init(GstClockTime start, GstClockTime end, GstClockTime frame_duration);
+
+    bool addPlaySegment(GstClockTime begin, GstClockTime end);
+    bool addPlaySegment(MediaSegment s);
+    bool removePlaySegmentAt(GstClockTime t);
+    bool removeAllPlaySegmentOverlap(MediaSegment s);
+    std::list< std::pair<guint64, guint64> > getPlaySegments() const;
+
+    inline float *Array() { return array_; }
+    inline size_t ArraySize() { return array_size_; }
+
+private:
+
+    GstClockTime start_;
+    GstClockTime end_;
+    size_t num_frames_;
+
+    float *array_;
+    size_t array_size_;
+    MediaSegmentSet segments_;
+    MediaSegmentSet::iterator current_segment_;
+
+};
+
+#endif // TIMELINE_H