By Marc Lichtman | January 20, 2026
Bluefile Converter
The SigMF leadership is excited to announce that the sigmf-python package Release v1.6.1 includes the addition of a converter for the MIDAS Blue and Platinum BLUE RF recording formats (commonly .cdif files).
This allows you to seamlessly integrate BLUE file recordings into your SigMF workflows.
The converter automatically detects BLUE file formats and can create standard SigMF file pairs, archives, or Non-Conforming Datasets (NCDs) that reference the original recording.
Original BLUE header information is preserved in the SigMF metadata under the blue: namespace.
A big thanks to Teque5 and KelseyCreekSoftware for their work!
Python API Example
You can use the converter directly within your Python scripts. If no output path is provided, a metadata-only SigMFFile object for a Non-Conforming Dataset (NCD) is returned without writing any files.
from sigmf.convert.blue import blue_to_sigmf
# Convert a BLUE file to a standard SigMF file pair
meta = blue_to_sigmf(blue_path="recording.cdif", out_path="recording")
# Create an NCD object in memory (no files written)
meta = blue_to_sigmf(blue_path="recording.cdif")
# Access samples and metadata
all_samples = meta.read_samples()
sample_rate = meta.sample_rate
# Original bluefile metadata preserved (in `fixed`, `adjunct`, and `extended` keys)
meta.get_global_field('blue:adjunct')
{'xstart': 0.025, 'xdelta': 5.5555555555555555e-08, 'xunits': 1}
Command-Line Example
The converter is also integrated into the unified sigmf_convert command-line tool, which automatically detects the input file format.
# Convert a .cdif file to a SigMF archive
sigmf_convert recording.cdif recording.sigmf --archive
# Create a non-conforming dataset (metadata only, references original data)
sigmf_convert recording.cdif recording --ncd
For questions/comments/feedback feel free to post a new issue to the python package github repo.