blip25-mbe 0.1.1

Python bindings for blip25-mbe — P25 MBE/IMBE/AMBE+2 vocoder family

blip25-mbe (Python)

Python bindings for blip25-mbe, a research-grade Rust implementation of the MBE / IMBE / AMBE+2 vocoder family for P25 Phase 1 and Phase 2 pipelines.

Patents. AMBE+2 is covered by US 8,359,197 until 2028-05-20. See PATENT_NOTICE.md.

Install

pip install blip25-mbe

Wheels are published for Linux (manylinux 2_28), macOS (x86_64 + arm64), and Windows for Python 3.9+.

Quick start

import numpy as np
import blip25_mbe

# One-shot frame round-trip
vc = blip25_mbe.Vocoder(blip25_mbe.Rate.IMBE_7200X4400)
pcm_in = np.zeros(vc.frame_samples, dtype=np.int16)   # 160 samples = 20 ms
bits = vc.encode_pcm(pcm_in)                          # 18-byte FEC frame
pcm_out = vc.decode_bits(bits)                        # back to np.int16

# Streaming over arbitrary-sized chunks
enc = blip25_mbe.LiveEncoder(blip25_mbe.Rate.AMBEPLUS2_3600X2450)
for chunk in pcm_chunks:                              # any size, any rate
    for frame in enc.push(chunk):
        socket.send(frame)                            # 9 bytes each

# Wire-format bridge (Phase 1 IMBE ⇄ Phase 2 AMBE+2)
tc = blip25_mbe.Transcoder(
    blip25_mbe.Rate.IMBE_7200X4400,
    blip25_mbe.Rate.AMBEPLUS2_3600X2450,
)
out_bits = tc.transcode(in_bits)

encode_pcm accepts any np.int16 array; decode_bits returns a fresh np.int16 array. Length must match vc.frame_samples / vc.fec_frame_bytes.

Rates

Python	Codec	Wire size	Bitrate
Rate.IMBE_7200X4400	IMBE	18 bytes	7 200 bps
Rate.IMBE_4400X4400	IMBE no-FEC	11 bytes	4 400 bps
Rate.AMBEPLUS2_3600X2450	AMBE+2	9 bytes	3 600 bps
Rate.AMBEPLUS2_2450X2450	AMBE+2 no-FEC	7 bytes	2 450 bps

Building from source

pip install maturin
maturin develop --release       # editable install into current venv
pytest                          # smoke tests

Sibling packages

blip25-mbe is the vocoder wrapper. Future blip25 components (decoder / SDR layer) will ship as separate PyPI packages with their own blip25_* import names — they don't share a namespace with this one.

License

MIT — see LICENSE.