Are the Magenta lib and Sound Banks loaded for each instance of the player?

[lautarodragan]

Hey there! First of all I want to say this is an awesome project. Thank you so much for building it and making it available for everyone.

Regarding my question: I've placed about 20 <midi-player sound-font>'s in my page, and the Memory footprint (as show by Google Chrome's Task Manager) grew to over 2.5gb! Event over 4.8gb at times (seems pretty random). And the page usually hangs indefinitely, too. I need to kill the tab from the Task Manager.

If I use no sound-font, it's only ~67mb. Without loading this script at all, it's ~46mb.

The RAM footprint seems to be related to the amount of instances. Some numbers

• 7 instances: 974mb.
• 5 instances: 568mb.
• 3: 384mb.
• 1: 230mb.

I could dynamically add and remove instances of the elements to limit the memory footprint, but UI and UX would suffer. Is there a way to globally load this library's dependencies, once for all instances?

[cifkao]

The Magenta library is loaded only once, but a separate SoundFontPlayer instance is created for each player and its loadSamples() method is called. This way, only the samples necessary for playing the sequence are loaded; however, this is done separately for each instance, which is probably why you are seeing this kind of memory footprint.

I think the best and probably also the easiest way to solve this would be to modify SoundFontPlayer (in Magenta) to use a shared instance of SoundFont instead of creating a new one for each player (provided that the SoundFont URL is the same). Otherwise a similar workaround could probably be implemented here.

[cifkao]

@lautarodragan For now you could perhaps try implementing a workaround on your end where you loop over your players (before actually loading content into them) and make sure player.player.soundFont is the same object for all of them, and let me know if that solves your problem.

[lautarodragan]

Thanks for answering @cifkao! I'll give that a try.