anchor.diff:  	(rcursor rec) (chunk-queue rec)
   	(wcursor rec) (cdr (chunk-queue rec))))
   
  +(defmethod pop-chunk-rcursor ((rec stream-record))
  +  (pop (rcursor rec)))
  +
   (defgeneric stream-playback-start (stream-record))
   
   (defgeneric stream-playback-stop (stream-record))
  
positive.code: (defgeneric decode-media-stream (record fsize input-stream))
  
  (defmethod decode-media-stream ((rec stream-record) fsize input-stream)
    (read-sequence (frame (ar (wcursor rec))) input-stream :end fsize))
  
  (defgeneric decode (stream)
    (:documentation "Decodes the video stream"))
  
negative.code:    (player-callback :accessor player-callback :initarg :player-callback :initform nil) ;;called once all headers are processed
     (width :accessor width :initarg :width :initform 640)
     (height :accessor height :initarg :height :initform 480)
     (stream-records :accessor stream-records :initform '())
     (finish :accessor finish :initform nil)
     (pause :accessor pause :initform nil)
     (pause-lock :accessor pause-lock :initform (bt:make-lock "pause"))))
  