PC Musician 2000/PC_Musician_2000.iso/PCMUSIC/SEQUENCE/CAL_CONT/C-MPLMIT.CAL

Text File | 1991-08-26 | 4.6 KB | 176 lines

;;; Robert C. Prince, III  Cakewalk Pro SN: 406176-CP-4.0A
;;; P. O. Box 8043
;;; Athens, GA 30603-8043
;;; [phone]
;;;
;;; C-MPLIMT.CAL
;;;
;;; This is a CAL program that acts similar to an electronic compressor/
;;;  limiter by scaling velocity and adding some set amount to velocity
;;;  to make up for losses caused by the scaling.
;;;
;;;  It allows you to set an upper limit for the compressed velocities.
;;;
;;;  It works on any MIDI instrument that correlates velocity with volume.
;;;  If velocity affects anything but volume, you will get some wierd results!
;;;
;;;  NOTE: Enter the first number of the compression ratio
;;;             desired TIMES 10!
;;;
;;;        If you want a compression ratio of
;;;                                            2:1, enter 20.
;;;                                          1.5:1, enter 15.
;;;
;;;  Remember, the higher the compression ratio, the closer
;;;         you bring the note velocities together.
;;;
;;;  You can have the pgm figure how to center the compressed
;;;         velocities, but you have to provide the highest velocity
;;;         to be compressed. The fastest way to do that is to run
;;;         the companion pgm HIVEL.CAL, which will do all the searching
;;;         for you.
;;;
;;;        OR
;;;
;;;        You can provide the offset you want.
;;;
;;;        AND/OR
;;;
;;;        You can run VELOCITY.CAL after this pgm, adding or subtracting
;;;         a fixed amount to all velocities.
;;;
;;; The file is named so it will be the first among the C's when
;;;  selecting a CAL pgm.
;;;
;;; *******************************************************************
;;; Prolog

(do

  ; set variables
  (int CompRatio 20)  ; the Compression ratio denominator times ten
  (int Limit 127)     ; limiting value for velocity
  (int auto 0)        ; should pgm automatically center resulting velocities?
  (int HiVel 127)     ; highest velocity to be compressed
  (int Constant 0)    ; constant amount to add to velocity after compression
  (int TempVel 0)     ; temporary variable for Velocity
  (int Yes 1)         ; Yes = 1
  (int No 0)          ; No = 0
  (int c 0)           ; counter to let user know something's going on

  ; get user input
  (getInt CompRatio
        "Enter the 1st number of the compression ratio times 10: " 10 200
  )

  (getInt Limit "Enter the highest velocity desired: " 0 127)

  (getInt auto "Automatic Centering of Velocities (0=No 1=Yes)? " 0 1)

  ; was auto chosen?
  (switch auto

    ; yes, so do the following
    Yes
      (do
        ; have user enter the highest velocity
        (getInt HiVel "Enter the highest velocity to be compressed: " 0 127)

        ; figure what the compressed highest velocity will be
        (= TempVel (/ (* HiVel 10) CompRatio))

        ; get the dif between uncompressed high vel and compressed hi vel
        (= Constant (- HiVel TempVel))

        ; divide the dif by 2 for correct constant to add
        (/= Constant 2)

      ; close the yes auto chosen do paren
      )

    ; no, auto was not chosen
    No

      (getInt Constant "Enter velocity to add after compression: " -127 127)

  ; close switch paren
  )

; close the do/prolog paren
)

;;; *****************************************************************
;;; Body
;;;

(do

  ; let user know something's up
  (message "Ratio: " CompRatio
           "to 10  Velocity Limit: " Limit
           "  Notes: " c
           "  Events: " (index)
  )

  ; if the kind of event is a note do something
  (if (== Event.Kind NOTE)

    ; yes it is a note event, so let's do some compression/limiting
    (do

      ; compress

        ; multiply velocity times 10
        (= TempVel (* Note.Vel 10))

        ; now divide result by the ratio
        (/= TempVel CompRatio)

        ; add the constant to make up for volume loss
        (+= TempVel Constant)

      ; limit, if necessary
        (if (> TempVel Limit)

          ; yes, the new velocity exceeds the limit, so make it equal the limit
          (= TempVel Limit)

          ; no, the new velocity does not exceed the limit
          NIL
        )

      ; change the velocity
        (= Note.Vel TempVel)

      ; bump up counter
        (++ c)

    ; close off the yes it is a note do paren
    )

    ; it is not a note, so do nothing
    NIL

  ;close off if it is a note paren
  )

; close off body/do paren
)

;;; *****************************************************************
;;; Epilog
;;;

NIL