LPTrack

LavaPlayer encoded track encoder and decoder.

Introduction

LPTrack is a small library which allows you to interpret the encoded track data used by LavaPlayer.

This is useful when you're dealing with standalone LavaLink instances like Lavalink and Andesite, because it allows you to interpret the track data directly.

Installation

From PyPI

pip install lptrack

Usage

import lptrack

track = lptrack.Track(
    version = 2,
    source = lptrack.Youtube(),

    info = lptrack.TrackInfo(
        title="A song",
        author="Some random artist",
        duration=120,                   # duration is in seconds!
        identifier="dQw4w9WgXcQ",
        is_stream=False,
    ),
)

encoded = lptrack.encode(track)
print(encoded)
# b'QAAARQIABkEgc29uZwASU29tZSByYW5kb20gYXJ0aXN0AAAAAAAB1MAAC2RRdzR3OVdnWGNRAAAAB3lvdXR1YmUAAAAAAAAAAA=='

decoded = lptrack.decode(encoded)

assert decoded == encoded

Obligatory rant about CESU-8

Without going into too much detail, LavaPlayer (or Java, to be more specific) uses a special encoding for strings called MUTF-8 which in turn is based on CESU-8. Characters from the BMP (which contains pretty much all characters from modern languages) are encoded like normal UTF-8. But special characters like emojis will be encoded in an incompatible manner.

While lptrack doesn't force you to use it, it's strongly recommended to have ftfy installed. It allows lptrack to properly decode MUTF-8 encoded strings. If ftfy isn't installed lptrack will treat the strings as UTF-8, but allows surrogates. Note that it doesn't parse the surrogates properly (i.e. it will look like a mess), but it will include them in the re-encoded track data.

ftfy is listed as a dependency of lptrack, so unless you really don't want it, you'll enjoy its benefits.

lptrack itself doesn't produce CESU-8 strings, so it's possible that the re-encoded track data differs from the original track data.

It's possible to manually set the desired codec using the keyword-argument string_codec which accepts a lptrack.strcodec.Codec instance. The following values are pre-defined:

• lptrack.strcodec.UTF8: Allows surrogates but doesn't parse them properly. Should be used if re-encoded track data needs to be equal to the input.

• lptrack.strcodec.MUTF8: Codec handling CESU-8. Requires ftfy to work.

• lptrack.strcodec.DEFAULT: MUTF8 if ftfy is installed, UTF8 otherwise. This codec is used by default.

• lptrack.strcodec.UTF8STRICT: Same as UTF8 but rejects surrogates outright.