A method for encoding a frame having a plurality of blocks in a video stream using transform-domain intra prediction is disclosed. The method includes generating, e.g., using a two-dimensional transform, a set of transform coefficients for a current block, generating, e.g., using a one-dimensional transform, a set of transform coefficients for previously coded pixel values in the frame, determining, using the set of transform coefficients for the previously coded pixel values, a set of transform coefficients for a prediction block, determining a residual based on the difference between the set of transform coefficients for the current block and the set of coefficients for the prediction block, and encoding the residual.

Transform-domain intra prediction

A packet loss recovery technique based on interleaving is proposed for uncompressed high-fidelity audio transmission. The audio samples are interleaved for transmission to avoid burst errors. The lost samples in the receiver are estimated by using quadratic fit interpolation (QFI). Finally a low pass filter (LPF) is applied to the estimated data for suppressing high-frequency aliasing caused by data loss. Objective evaluation of the performance is given by the peak signal-to-noise ratio (PSNR). Simulation results show that the proposed method reconstructs the lost data effectively, and has good performance with respect to the PSNR.

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A Low Complexity Packet Loss Recovery Method for Audio Transmission

Speech excitation signal recovering based on a novel error mitigation scheme under erasure channel conditions

One of the well-known problems of Code-Excited Linear Prediction (CELP)-type codec is its vulnerability to a frame erasure. When a frame is erased, the inter-frame dependency introduced by the Long Term Prediction causes a desynchronization of the Adaptive Codebook (ACB) which introduces in its turn an error propagation through the correctly received frames. In this paper, we propose a media-specific Forward Error Correction (FEC) method using a Pitch-Pulse Codebook (PPCB)-based approach to model the ACB contribution for voiced frame (frame onset) determined under Zero Crossing Rate constraint. The PPCB uses a single pulse optimized by Multipulse Maximum Likelihood Quantization algorithm to model the pitch-like contribution at the encoder side while the quantized version of that pulse will be sent as FEC information to resynchronize the ACB at the decoder side after a frame erasure. Through this approach a noticeable improvement of the synthesis speech quality is achieved under adverse channel conditions with the advantage of low computational complexity while the legacy bit-rate of the codec is kept unchanged.

Low complexity forward error correction for CELP-type speech coding over erasure channel transmission

In this paper, we utilize sender-based Forward Error Correction (FEC) techniques to enhance the robustness of packet loss recovery for AVS Mobile speech and audio (AVS-M) codec. Two FEC schemes are proposed which take the advantage of the codec's structure characteristics and do not introduce extra delay. The objective and subjective listening tests results show that the two methods achieve higher reconstructed quality than the codec's original frame erasure scheme in the case of packet loss.

Jianli Liu

Papers

FEC-based packet loss recovery for AVS-M audio codec