Improved frame erasure concealment for CELP-based coders

Abstract

This paper describes new techniques for concealing frame erasures for CELP-based speech coders. Two main approaches were followed: interpolative, where both past and future information are used to reconstruct the missing data, and repetition-based, where no future information is required. Key features of the repetition-based approach include improved muting, pitch delay jittering, and LPC bandwidth expansion. The interpolative approach can be employed in Voice over IP scenarios at no extra cost in terms of delay. Applied to the ITU-T (3.729 ACELP 8 kb/s speech coding standard, both interpolation-and repetitionbased techniques outperform standard concealment in informal listening tests.

Distributed subframe interleaving: A new solution for packet loss resilient speech coding

“…Since the 3 rd and 4 th packets in DSI stream are sent simultaneously at the transmitter, we can utilize the received 4 th packet as well as previous received packets when concealing the lost packet without introducing extra delay at the receiver. On the other hand, interpolation [9] is proved to produce better concealment than simple extrapolation when future speech frames are available. Hence, in our scheme, parameter interpolation is adopted to reconstruct the missing information.…”

Burst Packet Loss Concealment Using Multiple Codebooks and Comfort Noise for CELP-Type Speech Coders in Wireless Sensor Networks

“…The sender-based algorithms, for example forward error correction (FEC), require additional bits used for being processed in the decoder when frame losses occur [ 6 ]. On the other hand, the receiver-based algorithms, including repetition based concealment [ 7 ] and interpolative concealment [ 8 ], have advantages over the sender-based algorithms since they do not need any additional bits.…”