The emergence of time-varying heterogeneous network environments and the convergence of traditional consumer electronics and mobile communications have led to a clear need for universal sound codecs. Currently, such codecs do not exist. The objective of the ARDOR project is to develop a universal sound codec that adapts to the time-varying characteristics of the input signal, to userpreferences, and to time-varying network and application constraints, such as bitrate, quality, latency, and channel errors. This objective will be achieved with a rate-distortion optimisation control system, using an innovative perceptual distortion measure. This system will configure into the most optimal codec using a set of advanced, complementary sub-coding strategies and will provide the versatility required for the ambient intelligent landscape that is currently developing in society.
The objective of the ARDOR project is to meet the need for a universal codec that has been created by the emergence of time-varying heterogeneous networks and by the convergence of traditional consumer electronics with mobile communications. A universal sound codec will be developed that adapts to the time-varying characteristics of the input signal, to time-varying network and application constraints and to user-preferred codec attributes. The codec will be based on an architecture consisting of a set of advanced sub-coding strategies, and a control system that allocates rates and signal components to each sub-coder using an innovative perceptual distortion measure.
DESCRIPTION OF WORK
The development of a truly adaptive codec is a challenge to the merging fields of speech and audio coding that will require innovations on several fronts. Within the project, a codec will be created that encodes generic audio with the most appropriate combination of signal models, given the imposed constraints as well as the available sub-coders. The work can be divided into three parts corresponding to the three codec components:
1) A rate-distortion-theory based optimisation mechanism that configures the ARDOR codec such that it operates most efficiently given the current, time-varying, constraints and type of input signal. For this purpose it will control:
2) a set of sub-coding strategies, each of which is highly efficient for encoding a particular type of input-signal component, e.g.: tonal, noisy, transient, or harmonic signals. The appropriate rate and signal-component allocation for each particular sub-coding strategy will be based on:
3) an advanced, new perceptual distortion measure that provides a perceptual criterion for the rate-distortion optimisation mechanism. The extensive research work on the three-codec components will be supported by the development of a dedicated flexible software platform, and by listening tests that will be performed during the project. They will provide essential feedback that will lead to refinement of, and further innovation in, all aspects of the codec. The final phase of the ARDOR project will be the development of a demonstrator of the codec.
Funding SchemeCSC - Cost-sharing contracts
75505 Paris 15
100 44 Stockholm
2628 BL Delft