DSDcc is a C++ library for digital voice decoding, offering a complete rewrite of the original DSD project. It targets developers integrating speech decoding into applications like SDRangel, providing a cleaner, library-centric API. The primary benefit is a more flexible and embeddable decoder for various digital radio standards.

How It Works

DSDcc operates by pushing audio samples to a central DSDDecoder object, facilitating library integration. It processes samples to extract symbols and then decodes various digital voice formats (DMR, D-Star, dPMR, YSF) using specialized objects. An optional mbelib wrapper handles AMBE frame decoding and audio output, with support for upsampling to 48 kHz.

Quick Start & Requirements

• Install via cmake and make.
• Requires mbelib for full audio decoding (optional, compile with -DUSE_MBELIB=ON).
• Supports DVSI AMBE3000 serial devices via SerialDV (requires separate installation).
• Input: S16LE samples at 48 kS/s. Output: S16LE samples at 8 kS/s (or upsampled).
• Example usage: socat stdout udp-listen:9999 | dsdccx -i - -fa -o - | play -q -t s16 -r 8k -c 1 -
• Documentation: dsdccx -h

Highlighted Details

• Rewritten symbol timing and DMR processing for improved performance.
• Supports DMR/MOTOTRBO, D-Star, dPMR, and Yaesu System Fusion (YSF).
• Optional mbelib dependency for AMBE decoding, with clear patent warnings.
• Binary dsdccx supports piping and integration with serial devices like ThumbDV.

Maintenance & Community

• Active development branches (master, dev).
• No explicit community links (Discord/Slack) or major contributor mentions in the README.

Licensing & Compatibility

• Primarily licensed under GPLv3.
• mbelib usage may involve DVSI Inc. patents; users must assess their jurisdiction.
• GPLv3 license may impose copyleft restrictions on derivative works.

Limitations & Caveats

• mbelib usage carries potential patent infringement risks and requires separate installation.
• FTDI device latency issues may affect serial device compatibility on newer Linux kernels (requires manual configuration).
• Voice full rate with SerialDV is not supported for Yaesu System Fusion.