ly2video uses old version of ly module; conflicts with python-ly package

[wbsoft]

When ly2video is installed, the toplevel ly Python package conflicts with the ly module of the python-ly package. That package in turn, is needed to run Frescobaldi. I decided to make ly a standalone package so other tools (such as ly2video) can use it as well.

ly2video is using an old version of the same ly module, and probably could be changed so it depends on the python-ly package. The ly parser has improved since then and is maintained very well. I am willing to investigate the effort needed to use the parser from the newer ly module, from the python-ly package. And I can help making the changes. When that is done, python-ly becomes a dependency of ly2video.

An easier solution could be to move the ly module in ly2video to a private space or another name, such as ly2v.ly or ly2vly.

[aspiers]

Thanks a lot for the information and the offer to help fix this! I would love to see this fixed - please do investigate the effort involved and let me know what you find :) If it's not easy and quick to do then I agree that renaming ly to ly2vly or similar is a good short-term workaround.

[wbsoft]

I will have a look the coming days. Thanks for your prompt reply!

[wbsoft]

If I understand correctly, you are using ly to get the pitches of the source document, mapped to their location in the source document. You are using the changes that are recorded when performing a relative-to-absolute conversion to get the real pitch.

In the (much improved) structure of python-ly package, a LilyPond source file is now represented by a ly.document.Document (automatically tokenized), and you can register ly.document.Cursor instances to point to a certain position. Then you can perform a thing like relative-to-absolute to the Document. Although the document changes, the Cursors still point to the correct locations. The ly.document module is very mature and stable.

So I will try to take the following approach: I will load the LilyPond file using ly.document. I will make Cursors for every Pitch in the document, mapped to their current location. Then run ly.pitch.rel2abs on the document. All cursors now point to the possibly changed pitch. Then we map the pitch values to the original (line, column) locations.

[wbsoft]

By the way, do you know that LilyPond also makes the pitch absolute when reading a music expression? If I analize a (make-music 'RelativeOctaveMusic) construct, it seems that the octaves are already converted to their absolute value. So you could get them from LilyPond as well.... or do I miss something?

[aspiers]

You probably didn't miss anything - could easily have been due to my ignorance :)

[Stemby]

This bug report seems to be related to #19.

[mtarenskeen]

I wanted to report this today, but it seems it's a known issue. Hope there will be a fix soon, and the result will be easy way to install ly2video, even when, or especially when, Frescobaldi and python-ly are already installed on my system. I can even imagine ly2video could be an interesting plugin, integrated in Frescobaldi, that could be called by selecting it from Frescobaldi's File->Export menu. Anyway, glad to see things happening with the development of this project again.

[aspiers]

Hi again @wbsoft, I would love to see ly2video switch to using this stable library in the manner you suggest. Clearly that's a far superior approach to relying on some old code which IIRC is frankenstein parts stolen from an old version of Frescobaldi. Please let me know if you are able to help with this!

[uliska]

And I'd say it would be cool if we could integrate it in Frescobaldi: add an entry in the Helpers pref page, and when that's set enable the menu item in Export ...

[aspiers]

@uliska Great idea - maybe you want to open a separate issue in Frescobaldi for that?

[uliska]

Ok, I'll do so if I think if of it when I'm at a PC again -- Diese Nachricht wurde von meinem Android-Mobiltelefon mit K-9 Mail gesendet.

[aspiers]

So this should no longer clash with an install of python-ly. The final step will be to switch ly2video from using its own ancient version of Frescobaldi's ly library to using a modern python-ly. That is being tracked in #19 so I think I can close this.