Re: Experience with several import filters

[David Wright]

On Tue 03 Jan 2017 at 09:50:05 (+0100), Urs Liska wrote:
> Jan-Peter and I will have to give a report of the current state of
> import/export options to and from LilyPond. As there are a number of
> tools I have never used
> (http://lilypond.org/doc/v2.19/Documentation/usage/converting-from-other-formats)
> I would like to ask for any comments regarding the usability of these
> tools: I know I could search the archives but I would prefer current
> statements of people who are actually using them (or don't use them
> because they don' work as expected).

I've used rosegarden a fair bit; like Joram, it tends to be CPDL
scores where the formats available are, say, .mid/.sib/.pdf etc
and it has saved me a lot of time and effort, even though I can
input conventional choral music into LP pretty quickly and
accurately (\relative mode).

My recipe reads:

 Kill any xmms processes
 Start rosegarden
 Alt-F -> import midi
 Wait for everything to settle
 Alt-F -> export lilypond
 20pt
 (leave non-muted, letter, english)
 OK
 Wait for everything to settle
 Exit
 (discard output)
 ly "reformat; translate english; abs2rel; transpose c c" -o output.ly 
ex-roseg.ly

I discard everything except the notes. Then I apply careful systematic
edits to the output which I've never bothered to program into python,
just relying on emacs macros.

Just as an example, the ties over barlines appear as

        ff 4 ef 2 df 4
        % warning: overlong bar truncated here |
        \skip 4 c 4 df 2  |
        %% 50

which can be treated with a macro that does (in English)
 kill the warning
 go left 2 items (to before df)
 copy the item (df)
 go to end of line
 insert ~
 go forward one item (to past \skip)
 insert space and the copied df
 go to start of line
 kill one item (\skip)
 search for "overlong bar"

The macro is "learnt" on the first occurrence and then repeated
in quick time. However, it takes a some experience and care.
The example above would not work as it stands if it occurred one
bar earlier because the %% 50 would screw it up; ie I have to
have already stripped out the bar numbers before I start this
process.

That example may look complicated to some, but actually that makes
it less tedious (for me) than just typing the .pdf into LP, which
I would happily do in the absence of a .mid file.

Cheers,
David.