Encoder Assisted Frame Loss Concealment for MPEG-AAC Decoder

Abstract

This paper proposes an efficient method for frame loss concealment within the advanced audio coding (AAC) decoder, which can effectively mitigate the adverse impact of transmission errors on the reconstruction quality. The lost frame information is estimated in the modified discrete cosine transform (MDCT) domain in terms of magnitude and sign of the coefficients. A computationally efficient approach that is capable of providing accurate estimation is employed for the magnitude estimate. Enhanced sign estimation is developed and implemented, which exploits extra information from encoder. Extensive subjective quality evaluation demonstrates that the proposed method achieves substantial quality improvement with minimal encoder assistance.

An Improved Frame Loss Concealment Algorithm Based on the Mixed Excitation Linear Prediction

“…There are no need of the encoder's participation and additional bitstream. Therefore it can satisfy the requirements of real-time transmission [2].…”

“…There are no need of the encoder's participation and additional bitstream. Therefore it can satisfy the requirements of real-time transmission [2].This paper proposes a frame loss concealment algorithm based on the Mixed Excitation Linear Prediction (MELP).The parameters such as LSF, Pitch, Gain, are vital to the synthesized speech in the Decoder. During transmission, the speech signal frames have a certain correlation, to recover the parameters of the lost frame with frames before and after itself is helpful to improve the speech quality.…”