Re: midifile output name

[Thomas Morley]

2016-09-29 20:19 GMT+02:00 bart deruyter <address@hidden>:
> Hi all,
>
> I've got a collection of etudes for my students here, included in one file,
> to create one pdf.
> I've enabled midi, but now I've got a bunch of midi files which all have the
> name of the lilypond document, like this:
>
> The .ly file with the collection is called "Study collection.ly"
> The midi files then are named:
> Study collection.midi
> Study collection-1.midi
> Study collection-2.midi,
> etc.. (up to 30 for now).
>
> When I render one etude separately, the midi file gets the name of that
> separate file (e.g. andante.ly gives andante.midi), but when rendered in the
> collection file it would be named "Study collection-25.midi" because it is
> the 25th included file.
>
> All etudes are in separate lilypond files with a "\score", so I was
> wondering if there is a way to define a custom filename for the midi-file,
> for each score, which gets passed through to the collection file.
>
> Is this possible?
>
> thx,
>
> Bart



You could try the below.

Please note:
- it heavily messes with well hidden internals
- it's not tested apart from the included example
- there may be bleed over, while compiling multiple files (not tested)
- the default behaviour is not longer available as long as these
definitions are applied


\version "2.19.48"

%% c/p from midi.scm
#(define (performance-name-from-header header)
  (define (metadata-lookup-output overridevar fallbackvar)
    (let* ((overrideval (ly:modules-lookup (list header) overridevar))
           (fallbackval (ly:modules-lookup (list header) fallbackvar))
           (val (if overrideval overrideval fallbackval)))
      (if val (ly:encode-string-for-pdf (markup->string val)) "")))
  (if (null? header)
      ""
      (metadata-lookup-output 'midititle 'title)))

%% taken from midi.scm and changed
#(define-public (write-performances-midis-alt performances basename . rest)
  (let ((midi-ext (ly:get-option 'midi-extension)))
    (let
        loop
      ((perfs performances)
       (count (if (null? rest) 0 (car rest))))
      (if (pair? perfs)
          (let ((perf (car perfs)))
            (ly:performance-write
             perf
             ;; original:
             ;(if (> count 0)
             ;    (format #f "~a-~a.~a" basename count midi-ext)
             ;    (format #f "~a.~a" basename midi-ext))
             ;; changed to:
             (format #f "~a.~a"
               (performance-name-from-header (ly:performance-header perf))
               midi-ext)
             (performance-name-from-header (ly:performance-header perf)))
            (loop (cdr perfs) (1+ count)))))))

%% tell lily to use the changed definition
#(module-set!
  (resolve-module '(lily))
  'write-performances-midis
  write-performances-midis-alt)


\book {
  \score {
    { \repeat unfold 10 c'4 }
    \header { midititle = "my-c-midi-name" }
    \layout {}
    \midi {}
  }

  \score {
    { \repeat unfold 10 d'4 }
    \header { midititle = "my-d-midi-name" }
    \layout {}
    \midi {}
  }

  \score {
    { \repeat unfold 10 e'4 }
    \header { midititle = "my-e-midi-name" }
    \layout {}
    \midi {}
  }
}

Cheers,
  Harm