DDi Codec is a precise digital equivalent of the classical Dolby-B/C noise reduction system for analog audio tape. It is the world’s first dedicated software capable of decoding or encoding Dolby-C formatted audio in digital domain, along with full backward compatibility to Dolby-B. Powered by the proprietary DSP engine, the decoding or encoding can be performed in realtime pace, which allows instant monitoring and control of quality.

Deeper optimal result can be achieved by using the advanced tools that come with the software, as specified below:

• The Reference Vernier is the primary tool for aligning Dolby Reference Level in an interactive and progressive manner. It supports either objective calibration (with Dolby Tone) or subjective estimation (without Dolby Tone).
• The Azimuth and Gap-Loss tools can compensate minor imperfection of analog tape player used for digitizing audio tapes.
• The Play Trim is another tool for compensating weakened signal on aged pre-recorded tapes.
• The EQ Converter offers digital translation between 120μs and 70μs IEC standards — if such a flexibility is not found on a given tape player/recorder.
• The built-in tone generator offers 400Hz 0dB signal at Dolby Reference Level for easy calibration.

All these tools can work independently from the Dolby-B/C codec, which can also be applied for refining non-Dolby formatted audio.

DDi Codec is a stand-alone GUI app without relying on any other DAW host. It let the computer perform as a outboard Dolby-B/C NR unit in one of the following four working modes:
• Audio-In to File (a digitizer/recorder).
• File to Audio-Out (a player).
• File to File (an off-line processor, with batch capability).
• Audio-In to Audio-Out (a through processor, with slight delay).

Currently supported audio file formats are:
WAV, FLAC, AIFF: up to 96k/24bit.
MP3, AAC, M4A: up to 48k/VBR.

• Excluding some proprietary variants having the common file extensions, or additional format-normalization may be required.

A VST plugin is also available as an optional software component of the application.

• Dolby-B and C are the tape noise reduction systems developed by Dolby Laboratories.