fixes #1050: export MF4 that contains structure channels to MDF v3

src/asammdf/blocks/mdf_v3.py

@@ -25,6 +25,7 @@
  arange,
  array,
  array_equal,
+ ascontiguousarray,
  column_stack,
  concatenate,
  dtype,
@@ -48,7 +49,7 @@
 from ..types import ChannelsType, CompressionType, RasterType, StrPathType
 from . import v2_v3_constants as v23c
 from .conversion_utils import conversion_transfer
-from .cutils import get_channel_raw_bytes
+from .cutils import data_block_from_arrays, get_channel_raw_bytes
 from .mdf_common import MDF_Common
 from .options import get_global_option
 from .source_utils import Source
@@ -1568,9 +1569,26 @@ def append(
 
  new_gp.sorted = True
 
- samples = fromarrays(new_fields, dtype=new_types)
+ try:
+ samples = fromarrays(new_fields, dtype=new_types)
+ block = samples.tobytes()
+ except:
+ struct_fields = []
+ for samples in new_fields:
+ size = samples.dtype.itemsize
 
- block = samples.tobytes()
+ if len(samples.shape) > 1:
+ shape = samples.shape[1:]
+
+ for dim in shape:
+ size *= dim
+
+ if not samples.flags["C_CONTIGUOUS"]:
+ samples = ascontiguousarray(samples)
+
+ struct_fields.append((samples, size))
+
+ block = data_block_from_arrays(struct_fields, cycles_nr)
 
  new_gp.data_location = v23c.LOCATION_TEMPORARY_FILE
  if cycles_nr: