Error-Resilience Transcoding of H.264/AVC Compressed Videos

We propose an error resilience transcoder based on the intra refresh technique for H.264/AVC videos. Our algorithm focuses on making decisions on the number of inserted intra MBs, allocations of proper MBs for intra refresh, and the quantization parameter for each P-frame, according to varying channel condition and frame contents. We build source distortion, channel distortion, and bit-rate models for prediction and adopt the Lagrangian multiplier approach for constrained optimization. Existing algorithms are compared in experiments. The results show that our algorithm improves PSNR by 0.282.76 dB, compared to the "equal intra refresh" approach. Our algorithm also outperforms CBERC [8] by 0.11.13 dB, with the same number of inserted intra MBs, but different MB priorities in allocation.