UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 14: ordinal not in range(128)

Hi!

I’m getting the error above when running a simple pynetdicom storage SCP.

I’m a bit new to python so it is sure to be a simple thing. Have been googling around for a while now without luck. Any help would really welcome!

from pynetdicom import (
     AE, debug_logger, evt, AllStoragePresentationContexts,
     ALL_TRANSFER_SYNTAXES
 )

debug_logger()

def handle_store(event):
     """Handle EVT_C_STORE events."""
     ds = event.dataset(encoding="utf-8")

     return 0x0000

handlers = [(evt.EVT_C_STORE, handle_store)]

ae = AE(ae_title=b'TEST')

storage_sop_classes = [
     cx.abstract_syntax for cx in AllStoragePresentationContexts
 ]
for uid in storage_sop_classes:
     ae.add_supported_context(uid, ALL_TRANSFER_SYNTAXES)

ae.start_server(('', 11112), block=False, evt_handlers=handlers)

And the error:

E: Unable to decode the received PDU data
E: 'ascii' codec can't decode byte 0xe2 in position 14: ordinal not in range(128)
Traceback (most recent call last):
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/dul.py", line 301, in _read_pdu_data
    pdu, event = self._decode_pdu(bytestream)
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/dul.py", line 133, in _decode_pdu
    pdu.decode(bytestream)
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/pdu.py", line 83, in decode
    self, attr_name, func(bytestream[sl], *args)
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/pdu.py", line 283, in _wrap_generate_items
    item.decode(item_bytes)
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/pdu_items.py", line 93, in decode
    setattr(self, attr_name, func(bytestream[sl], *args))
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/pdu_items.py", line 307, in _wrap_generate_items
    item.decode(item_bytes)
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/pdu_items.py", line 93, in decode
    setattr(self, attr_name, func(bytestream[sl], *args))
  File "/usr/local/lib/python3.8/dist-packages/pynetdicom/pdu_items.py", line 1386, in abstract_syntax_name
    value = UID(value.decode('ascii'))
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe2 in position 14: ordinal not in range(128)
D: Abort Parameters:
D: =========================== OUTGOING A-ABORT PDU ===========================
D: Abort Source: DUL service-user
D: Abort Reason: No reason given
D: ============================= END A-ABORT PDU ==============================

[scaramallion]

Why have you done ds = event.dataset(encoding="utf-8")? It should be just event.dataset.

Anyway, it seems like whatever you’re associating with is using non-conformant UIDs (they’re supposed to be encoded as ASCII). Could you bind the following to EVT_DATA_RECV and post the output?

from pydicom.utils import pretty_bytes

def debug_data(event):
    data = event.data
    LOGGER.debug(f"{' DEBUG - ENCODED PDU ':=^76}")
    slist = pretty_bytes(
        data, prefix=' ', delimiter=' ', max_size=None, items_per_line=25
    )
    for s in slist:
        LOGGER.debug(s)

    LOGGER.debug(f"{' END ENCODED PDU ':=^76}")


handlers = [(evt.EVT_C_STORE, handle_store), (evt.EVT_DATA_RECV, debug_data)]

[mijuny]

Hi!

I’m not aware if any other solution. For me, this simple and crude node is working with OsiriX:

import logging

from pydicom.uid import UID
from pynetdicom import AE, evt, AllStoragePresentationContexts, debug_logger, pdu
from pynetdicom.pdu_items import AbstractSyntaxSubItem
from pynetdicom.utils import validate_uid

def my_setter(self, value):
    if isinstance(value, UID):
        pass
    elif isinstance(value, str):
        value = UID(value)
    elif isinstance(value, bytes):
        try:
            value = UID(value.decode('ascii'))
        except UnicodeDecodeError:
            value = UID(value.decode('utf-8'))
    elif value is None:
        pass
    else:
        raise TypeError(
            'Abstract Syntax Name must be a pydicom.uid.UID, str or bytes'
        )

    if value is not None and not validate_uid(value):
        LOGGER.error("Abstract Syntax Name is an invalid UID")
        raise ValueError("Abstract Syntax Name is an invalid UID")

    self._abstract_syntax_name = value

AbstractSyntaxSubItem.abstract_syntax_name = AbstractSyntaxSubItem.abstract_syntax_name.setter(my_setter)

pdu.AbstractSyntaxSubItem = AbstractSyntaxSubItem

debug_logger()

# Implement a handler for evt.EVT_C_STORE
def handle_store(event):
    """Handle a C-STORE request event."""
    # Decode the C-STORE request's *Data Set* parameter to a pydicom Dataset
    ds = event.dataset

    # Add the File Meta Information
    ds.file_meta = event.file_meta

    # Save the dataset using the SOP Instance UID as the filename
    ds.save_as(ds.SOPInstanceUID, write_like_original=False)

    # Return a 'Success' status
    return 0x0000

handlers = [(evt.EVT_C_STORE, handle_store)]

# Initialise the Application Entity
ae = AE(ae_title=b'TEST')

# Support presentation contexts for all storage SOP Classes
ae.supported_contexts = AllStoragePresentationContexts

# Start listening for incoming association requests
ae.start_server(('', 11112), evt_handlers=handlers)

Running this in this conda env in macOS:

# Name                    Version                   Build  Channel
bzip2                     1.0.8                h620ffc9_4  
ca-certificates           2022.12.7            h4653dfc_0    conda-forge
certifi                   2022.12.7          pyhd8ed1ab_0    conda-forge
libffi                    3.4.2                hca03da5_6  
ncurses                   6.3                  h1a28f6b_3  
openssl                   1.1.1s               h03a7124_1    conda-forge
pip                       22.3.1          py310hca03da5_0  
pydicom                   2.3.1              pyh1a96a4e_0    conda-forge
pynetdicom                2.0.2              pyhd8ed1ab_0    conda-forge
python                    3.10.8               hc0d8a6c_1  
readline                  8.2                  h1a28f6b_0  
setuptools                65.5.0          py310hca03da5_0  
sqlite                    3.40.0               h7a7dc30_0  
tk                        8.6.12               hb8d0fd4_0  
tzdata                    2022g                h04d1e81_0  
wheel                     0.37.1             pyhd3eb1b0_0  
xz                        5.2.8                h80987f9_0  
zlib                      1.2.13               h5a0b063_0