Function to append a Serum-compatible comment to a WAV file so you don't have to enter 2048 every time you load a wavetable

serumchunk.py

from pathlib import Path
from struct import pack


def add_serum_chunk(wav_path: Path):
    # Existing WAV file must be in a 2048-samples-per-frame format.
    # See https://www.kvraudio.com/forum/viewtopic.php?t=517146
    comment = "<!>2048 00000000 wavetable (www.xferrecords.com)"
    encoded = comment.encode("utf8")
    chunk_id = b"clm "
    chunk_size = len(encoded)
    chunk_size_bytes = pack("<I", chunk_size)
    clm_chunk = chunk_id + chunk_size_bytes + encoded
    with wav_path.open("ab") as f:
        f.write(clm_chunk)