backend documentation?

[michaelherger]

Hi there

Is there any documentation available about the backend implementations? I'm currently using pipe to send the data to my own application. Alas, as it would buffer a ton of data, I'd have received multiple tracks already when the first track actually finishes. Therefore I was wondering how to go about this, whether it was possible to define a maximum buffer or something in the pipe. Or rate limit what it's sending out etc.

I could even imagine implementing an interaction with my application where librespot would allow it to buffer stuff, but be able to tell it "hey, change of track - get rid of buffered data!" etc. I would imagine that this is something which must have been implemented with most backends, but I don't get it...

[kingosticks]

What would the documentation describe? All backends fundamentally work the same. Librespot pushes/writes data into the backend as fast as it is allowed to i.e. as fast as write_bytes() returns. Backends can slow this all down (push back) by making the write take longer.

Linux pipes are effectively queues. You can set the size, and you control the rate you read from them in order to control the rate data is written into them. Does that help?

[michaelherger]

Thanks, that already helps! I'll look into write_bytes() then.

So there's no magic like catching skipping/seeking/pause etc. commands? Those backends would simply write whatever they receive. And they have little buffers, I assume? Otherwise playback would continue long after Spotify has stopped playing?

[kingosticks]

Yes. Tuning the buffer size is a tradeoff. With fast today's fast connections you should be able to get data quickly so only a small playback buffer is normally required.