Can't read specific, but seemingly valid SEG-Y file

[TheZappie]

I can't read specific, but seemingly valid SEG-Y file. What in segyio is triggering this (and is it an issue with the file or code)?

The file can be reached here: https://drive.google.com/file/d/1MXw_5dqoSYJlMoXWB7BJvqSY75GQnCsQ/view?usp=sharing

from pathlib import Path

path = r"/path/to/AN-A401.sgy"

a = Path(path).stat().st_size - 3600
trace_lenth = 2560 
b = trace_lenth * 4 + 240
assert (a % b == 0)
# asserting that the file length is exactly as it should be

import segyio

segyio.open(path, ignore_geometry=True, mode="r", endian='big')
# yields error: RuntimeError: trace count inconsistent with file size, trace lengths possibly of non-uniform

# Other programs do work, including seisee and obspy.
from obspy.io.segy.core import _read_segy
st = _read_segy(path, format="SEGY")

[TheZappie]

It is related to SEG-Y revision indicator in the binary header. Segyio does open it when I first do this:

with open(p, mode='rb+') as f:
    f.seek(3500)
    packed_data = struct.pack('>b', 1)
    f.write(packed_data)

    f.seek(3501)
    packed_data = struct.pack('>b', 0)
    f.write(packed_data)

[ajaust]

Sorry for the late response, but the project was not really active for some time and great that you were able to fix the issue. 🎉

Do you remember what initial value of the revision indicator was? We had some files with rev 2.0 or rev 2.1 indicator that worked fine with the recent versions of segyio.