Python version

'python=3.9.18 (main, Sep 11 2023, 13:41:44) \n[GCC 11.2.0]' 'os=Linux-6.5.5-200.fc38.x86_64-x86_64-with-glibc2.37' 'numpy=1.26.0' 'asammdf=7.3.14'

Code

MDF version

4.10

Code snippet

from asammdf import MDF, Signal
import numpy as np

timestamps = np.array([0.1, 0.2, 0.3, 0.4, 0.5], dtype=np.float32)

samples = [np.ones((5, 2), dtype=np.uint8)]
types = [("boolean_array_channel", "(2, )<u1")]
record = np.core.records.fromarrays(samples, dtype=np.dtype(types))
boolean_array_channel = Signal(
    record,
    timestamps=timestamps,
    name="boolean_array_channel",
)

mdf4 = MDF(version="4.10")
mdf4.append(signals=[boolean_array_channel], comment="Created by Python")
# set bit count to 1 to indicate that each uint8 value is a boolean flag in boolean_array_channel
mdf4.groups[0].channels[1].bit_count = 1
signal = mdf4.select([('boolean_array_channel', 0, 1)])[0]

assert((record == signal.samples).all())

Traceback

Traceback (most recent call last):
  File "/home/victor/Sandbox/simon-karlsson-cde-2023-09-28/reproduce.py", line 19, in <module>
    signal = mdf4.select([('boolean_array_channel', 0, 1)])[0]
  File "/home/victor/anaconda3/envs/asammdf/lib/python3.9/site-packages/asammdf/mdf.py", line 3443, in select
    for idx, sigs in enumerate(
  File "/home/victor/anaconda3/envs/asammdf/lib/python3.9/site-packages/asammdf/blocks/mdf_v4.py", line 8277, in _yield_selected_signals
    signal = self.get(
  File "/home/victor/anaconda3/envs/asammdf/lib/python3.9/site-packages/asammdf/blocks/mdf_v4.py", line 6692, in get
    vals, timestamps, invalidation_bits, encoding = self._get_array(
  File "/home/victor/anaconda3/envs/asammdf/lib/python3.9/site-packages/asammdf/blocks/mdf_v4.py", line 7106, in _get_array
    vals = frombuffer(data_bytes, dtype=dtype_fmt)["vals"]
ValueError: buffer size must be a multiple of element size

Description

No mdf file is needed to reproduce this issue. The mdf is constructed in the code above to reproduce the problem. We create an mdf from scratch where we have a signal that is a channel array of boolean values. Since it is booleans we set the bit count to 1. When trying to read the signal from the mdf, we get an error.

I found this issue when dealing with an mdf generated from the tool Silver (T-2022.03-2) from QTronic. The mdf created above reproduces that problem I originally found when importing the mdf from Silver with asammdf.

danielhrisca / asammdf