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About the song conversion in v4

Read here before asking in the forum ...

jazzysiggi User avatar
Administrator

Posts: 162

This issue doesn't touch the fakebook-only users

When you start the new v4 for the first time, Calypso will ask you, whether to convert your songs of the songbook viewer. What is the reason for this conversion you may ask? You may also realize, that your songs created with Calypso v4 could not be shared with users of the v3. In fact, those songs can be shared, but won't show any music scores. This is a pit fall I for myself have experienced several times (as the developer!). So what's all about this shitty conversion. Here are some background facts.

When I started with Calypso, I decided to make screenshots of the music score sheets you add to a song. Many of my PDFs I used for my songs consisted of a complete bigband arrangement or at least the rythm section part. But I just needed the piano scores. Therefore Calypso should make screenshots of some pages of these PDFs and thus allowe me, to get rid of them when I'm done. The option to make screenshots in b/w reduced the memory demands of the saved images.

In those days, there only existed one iPad (it was not even called the iPad 1). A year later the iPad 2 arrived. All was good until Apple gave us retina displays with 4 times more pixels in the same sized screen. Some users complained about some blur when starring to the music score sheets created on an iPad 1/2. To overcome this issue, they could re-edit the sheets, if they provided the original PDF. I think, only few users did that.

With the advent of the first iPad Pro with a 12.9" display, the situation got even worse. The songs of my Calypso veterans appeared really blurry on those new devices and may have reduced significantly the joy about a bigger screen. No wonder, because images of size 768x1024 are presented on a screen with 2048x2732 pixels. That's almost 3 times the amount of pixels in each dimension!

Again, these users could re-edit their song sheets. But another drawback of the screenshots become evident. The screenshots generated on an iPad Pro demanded almost 8 times the memory storage on an iPad 2. Compared to the file size of the originating PDF - which often is less than 100 kB per page if generated with a music score editor - the screenshots requiring more than 1 MB are a big waste of storage memory.

I decided to find an alternative for the screenshots. I finally found a way to extract a single page as a PDF out of the original PDF. That means, I get the original data for a single PDF page with the original data size: sometimes less than 100 kB (depending on how the PDF was created; badly scanned images could hold several MB for a single page). But the best thing for me and my fellow users is, these sheets now appear exactly as the original PDF. No blur because of low res. images, even when the song is created on an iPad 2 and shared to a 12" iPad.

Calypso still makes excerpts out of the original PDF. So, you still can delete the PDF after you've created your songs with it. That always was a feature which was highly apprectiated by many Calypso users.

There is another, minor advantage of that approach. If for whatever reason you want to change the layout of a music score, you don't need the originating PDF as in earlier versions. The PDF is still there.

To get these advantages for all your 'old' songs created with v3, you can convert them. As mentioned above, Calypso v4 asks you on its first start, whether you want to convert your songs. It is totally fine, if you won't convert your songs (for now or never :-). But if you are eager to use the new format, you of corse have to provide the original PDF files in the documents folder. Some lucky users may still have all the needed PDFs here. But even if you don't have any PDF files here, you should start the conversion. At the end of the conversion process Calypso will write a text file PDF conversion.txt with detailed information of this process. This text file includes a list of all missing PDF files. Certainly all your music score PDFs stay well organized on your desktop computer. So simply copy the needed files into Calypso's public folder (with iTunes, or better with such great tools like iMazing or iExplorer). Then, in the preferences switch the option Convert the songs again to ON. If you get low on memory, this procedure could be repeated several times with smaller chunks of PDF files.

When you restart Calypso after a conversion, the database will be cleaned. This will temporarily require additional storage memory but will very likely reduce the size of your database file.

There is another option in the settings, which handles conversion: Convert songs when selected. If switched ON (the default), each time you open a still to be converted song, Calypso will look for the underlying PDF and convert it on the fly. Also, if you are in Song Edit mode and a song is not yet converted, Calypso will write the missing file on top of your sheet. Thus you can easily convert song by song.

After a song is converted, Calypso has removed the prior screenshots from the database and instead holds PDF data of each sheet. If you share such a song with Calypso v3, the music score won't be shown. Prior to v4, Calypso presented you images, it doesn't know of any PDF data. After those older apps are upgraded to v4, all songs appear as you'd expect, though.

Besides the obvious advantages this new approach also has two drawbacks:

• it takes the iPad more time to show PDF data than an image
• it also needs a bit more runtime memory to show PDFs

Both disadvantages only become aware on an older iPad and if a song has many pages.


Is there a way to share my v4 song with a v3 user?

If you really need to share a song created or converted under v4, you could follow these steps:

    1. make a copy of the song. To do so, just export it as a local file and import it
    2. with the copy opened, enter the Song Edit mode.
    3. in the More menu choose Edit composed image.
    4. layout the PDF as needed followed by Set image
    5. repeat step 3 + 4 for each page of your song
This converts the PDF into the images required by earlier Calypso versions.

Hopefully you like this new approach like I do.
have fun & make good music

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