如何使用python在ID3v2 mp3文件上添加SYLT（同步歌词）标签？

我想使用 python 在我的 mp3 文件上添加来自 vtt 的同步歌词。我尝试使用诱变模块，但它没有按预期工作。

from mutagen.id3 import ID3, USLT, SLT
import sys
import webvtt

lyrics = webvtt.read(sys.argv[2])
lyri = []
lyr = []
for lyric in lyrics:
    times = [int(x) for x in lyric.start.replace(".", ":").split(":")]
    ms = times[-1]+1000*times[-2]+1000*60*times[-3]+1000*60*60*times[-4]
    lyri.append((lyric.text,ms))
    lyr.append(lyric.text)
fil = ID3(sys.argv[1])
tag = USLT(encoding=3, lang='kor', text="\n".join(lyr)) # this is unsynced lyrics
#tag = SLT(encoding=3, lang='kor', format=2, type=1, text=lyri) --- not working
print(tag)
fil.add(tag)
fil.save(v1=0)

我怎么解决这个问题？

我用mutagen解析了一个已经有SYLT数据的mp3文件，发现了SYLT的用法：

from mutagen.id3 import ID3, SYLT, Encoding

tag = ID3(mp3path)
sync_lrc = [("Do you know what's worth fighting for", 17640), 
            ("When it's not worth dying for?", 23640), ...]  # [(lrc, millisecond), ]
tag.setall("SYLT", [SYLT(encoding=Encoding.UTF8, lang='eng', format=2, type=1, text=sync_lrc)])
tag.save(v2_version=3)

但我不明白format=2, type=1 means.