MDF4.3

What's New in v4.2

New MDF 4.x Features

• MDF 4.3 support: new compression algorithms (ZstdSD, LZMA, LZ4) introduced in MDF 4.3
• VLSC (Variable Length Signal Channel): initial support for variable-length signal data
• New block types: CL, DS, CU, CV block parsing
• BOM reading and VD (Value Definition) block support
• SD block reading fixes

MFX / Compressed File Support

• MFXZ decompression no longer requires a temporary file on disk

File Finalization

• Finalization feature: cycle count and block size recalculation for unfinished recordings
• DL (Data List) block updates for finalization

Bug Fixes

• Unsorted data groups: bit masking now applied for non-byte-aligned channels
• Signed integer initialization: fixed stale high-byte bug for 24-bit signed integers in dataRead
• Integrity checks: multiple fixes for compressed (DZ) and empty data blocks with wrong size calculations
• Unfinalized DZ blocks: fixed wrong block length calculation
• Complex data types: fixes for f16 complex, general complex type bugs, and BOM+complex value handling
• MDF 2: bug fix for MDF 2 file reading
• Export: various export bug fixes
• resample(): discard intermediate arrays to reduce memory usage
• Null timestamp (1970-01-01T00:00:00) no longer raises an exception
• DG/CG keys changed from sequential integer to file position
• channel class attribute casing fixed (camelCase)
• Improved channel extraction in masterChannelList
• Native endianness check added
• Byte order handling fixed when returning a DataFrame
• copy() bug fix
• KeyError and overflow warning fixes

Python & NumPy Compatibility

• Python 3.13: Cython dataRead extension updated
• NumPy 2.x: backwards-compatible fromstring/fromarrays imports
• Minimum Python version raised to 3.9
• distutils dependency removed

Resample

• resample() now accepts interpolation options from scipy.interp1d

Performance

• Various read-path optimisations
• Memory usage reduced during large file reads

Packaging & CI

• GitHub Actions workflows for automated PyPI publishing (Linux x86_64/aarch64, Windows x86_64, macOS x86_64/arm64)
• pyproject.toml added for PEP 517 build support

Community Contributions

• Byte order fix when returning DataFrame (#220 — LaurentBlanc73)
• Data storage fix (#212 — LaurentBlanc73)
• Improved masterChannelList channel extraction (#213 — LaurentBlanc73)
• NumPy 2.x import compatibility + camelCase attribute fix (#215 — Pzdrs)
• Native endianness check and null timestamp fix (cyclichertz)