This study presents a chaos-based crypto-compression scheme to protect the H.264 advanced video coding (AVC) used for the applications of video conference. To this end, a selective encryption approach was adopted. The...
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This study presents a chaos-based crypto-compression scheme to protect the H.264 advanced video coding (AVC) used for the applications of video conference. To this end, a selective encryption approach was adopted. The authors proposed to encrypt the inter-prediction, the intra-prediction and the context adaptive variable length coding. The format compliance and compression ratio are conserved. Their encryption method is based on two piecewise linear chaotic maps for pseudo-random bit generators. The first is considered as a decision module to choose either to encrypt or not, whereas the second is used for the encryption. The proposed encryption techniques were developed and discussed, and their experimental results indicate that the scheme is secure and very efficient according to the computing times. Moreover, it is suitable for real-time application and convenient for all the H.264/AVC profiles or even with other video compression standards.
The authors propose efficient hybrid error resilience and error concealment (ER-EC) algorithms for H.264 3D video-plus-depth (3DV+D) transmission over error-prone channels. At the encoder, content-adaptive pre-process...
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The authors propose efficient hybrid error resilience and error concealment (ER-EC) algorithms for H.264 3D video-plus-depth (3DV+D) transmission over error-prone channels. At the encoder, content-adaptive pre-processing ER mechanisms are implemented by applying the context adaptive variable length coding (CAVLC), the slice structured coding, and the explicit flexible macro-block ordering. At the decoder, a post-processing EC algorithm with multi-proposition schemes is implemented to recover the lost 3DV colour frames. The convenient EC hypothesis is adopted based on the lost macro-blocks size mode, the faulty view, and the frame types. For the recovery of the lost 3DV depth frames, an encoder-independent decoder-dependent depth-assisted EC algorithm is suggested. It exploits the previously estimated colour disparity vectors (DVs) and motion vectors (MVs) to estimate more additional depth-assisted MVs and DVs. After that, the optimum colour-plus-depth DVs and MVs are accurately selected by employing the directional interpolation EC algorithm and the decoder MV estimation algorithm. Finally, a weighted overlapping block motion and disparity compensation scheme is utilised to reinforce the performance of the proposed hybrid ER-EC algorithms. Experimental results on standard 3DV+D sequences show that the proposed hybrid algorithms have superior objective and subjective performance indices.
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