A Bit Allocation Method for Object-Based Audio Coding Based on G.719 Codec

Object-based audio coding method is one of the most important technologies of 3D audio since it can effectively reconstruct each audio object while making the interaction between users and audio scene more flexible and personalized. A major challenge of object-based audio coding is the higher bit rate with the increase of the number of objects. Most of the existing object-based audio coding methods use downmixing to achieve a lower bit rate, while there is few research on how to encode each audio object individually and effectively. A bit allocation method for object audio coding based on G.719 is proposed, which encodes each audio object individually while allocating different bit rate to each object adaptively according to their acoustic importance. Firstly, the objects are attenuated and combined so as to allocate the total bits among the sub-vectors; Secondly, the attenuated objects are decomposed by HRTF to obtain their number of bits within each sub-vector. Experimental results show that our method can obviously improve the reconstructed audio quality at the same coding rate compared with the equal bit allocation method.