demux: adaptive: add buffer length

modules/demux/adaptive/plumbing/CommandsQueue.cpp

@@ -314,6 +314,11 @@ void CommandsQueue::setDrop( bool b )
     vlc_mutex_unlock(&lock);
 }
 
+mtime_t CommandsQueue::getDemuxedAmount() const
+{
+    return bufferinglevel - getFirstDTS();
+}
+
 mtime_t CommandsQueue::getBufferingLevel() const
 {
     mtime_t i_buffer;

modules/demux/adaptive/plumbing/CommandsQueue.hpp

@@ -145,6 +145,7 @@ namespace adaptive
             void Commit();
             bool isEmpty() const;
             void setDrop( bool );
+            mtime_t getDemuxedAmount() const;
             mtime_t getBufferingLevel() const;
             mtime_t getFirstDTS() const;