anchor.diff:  (defmethod find-mjpeg-stream-record ((avi avi-mjpeg-stream))
     (find-if #'(lambda (x) (eql (type-of x) 'mjpeg-stream-record)) (stream-records avi)))
   
  +(defmethod find-pcm-stream-record ((avi avi-mjpeg-stream))
  +  (find-if #'(lambda (x) (and (eql (type-of x) 'audio-stream-record)
  +			      (eql (compression-code x) +pcmi-uncompressed+))) (stream-records avi)))
  +
   (defmethod decode ((avi avi-mjpeg-stream))
     (with-open-file (stream (filename avi) :direction :input :element-type '(unsigned-byte 8))
       ;; read AVI header first
  
positive.code: 	     (average-bytes-per-second rec) (riff:read-u4 is)
  	     (block-align rec) (riff:read-u2 is)
  	     (significant-bits-per-sample rec) (riff:read-u2 is))
         (unless (eql (compression-code rec) 1)
  	 (setf (extra-format-bytes rec) (riff:read-u2 is)
  	       (extra-bytes rec) (make-array (extra-format-bytes rec) :element-type (stream-element-type is)))
  	 (read-sequence (extra-bytes rec) is)))
  
negative.code: 
  (eval-when (:compile-toplevel) 
    (defconstant +avif-must-use-index+ #x20) 
  
    (defconstant  +pcmi-uncompressed+ 1)
  
    (defconstant +avi-dht+
      #(#x01 #xA2 
  