Exploring ERP Distortions to Reduce the Encoding Time of 360 Videos

• Iago Storch UFPel
• Bruno Zatt UFPel
• Luciano Agostini UFPel
• Daniel Palomino UFPel

DOI: https://doi.org/10.5753/webmedia_estendido.2021.17602

Resumo

The encoding of 360 videos presents many challenges. These spherical videos require a planar projection stage prior to encoding, and there are no studies on how projection interferes with the encoder decisions. Also, due to the increased resolution, encoding 360 videos is computationally costlier than conventional videos. In this work, we perform an extensive evaluation of how the texture distortions caused by the projection interfere with the encoder’s behavior and exploit these interferences to propose multiple fast algorithms to accelerate the encoding. Experimental results show that the proposed algorithms reduce encoding time significantly with minor coding efficiency penalties, while the evaluations expose novel insights into the encoder behavior. The reached results are published in important events and journals.

Palavras-chave: Omnidirectional video, fast video coding, projection distortion, time saving

Referências

Cisco visual networking index: forecast and methodology 2017-2022, 2019.

I. Storch, L. A. da Silva Cruz, L. Agostini, B. Zatt, D. Palomino. 2019. The Impacts of Equirectangular 360-degrees Videos in the Intra-Frame Prediction of HEVC. Journal of Integrated Circuits and Systems 14, 1 (2019), 1-10.

I. Storch, G. Correa, B. Zatt, L. Agostini, D. Palomino. ESA360 - Early SKIP Mode Decision Algorithm for Fast ERP 360 Video Coding. In 2020 28th European Signal Processing Conference (EUSIPCO). IEEE, 535-539.

I. Storch, L. Agostini, B. Zatt, S. Bampi, D. Palomino. FastInter360: A Fast Inter Mode Decision for HEVC 360 Video Coding. In IEEE Transactions on Circuits and Systems for Video Technology, (2021), 1-15.

J. Vanne, M. Viitanen, T. D. Hamalainen, A. Hallapuro. 2012. Comparative rate distortion-complexity analysis of HEVC and AVC codecs. IEEE Transactions on Circuits and Systems for Video Technology 22, 12 (2012), 1885-1898.

G. Sullivan, J. R. Ohm, W.-J. Han, T. Wiegand. 2012. Overview of the high efficiency video coding (HEVC) standard. In IEEE Transactionson circuits and systems for video technology, 22, 12 (2012), 1649–1668.

HEVC Test Model, available at: https://hevc.hhi.fraunhofer.de/svn/svn_HEVCSoftware/. Access in Aug. 2021.

360Lib software, available at: https://jvet.hhi.fraunhofer.de/svn/svn_360Lib/. Access on Aug. 2021.

P. Hanhart, J. Boyce, K. Choi, J.-L. Lin. JVET common test conditions and evaluation procedures for 360 video. JVET meeting document L1012, 1-7, 2018.

G. Bjontegaard. Calculation of average PSNR differences between RD-curves. VCEG meeting document M33, 1-4, 2001.

I. Storch, B. Zatt, L. Agostini, G. Correa, L. A. da Silva Cruz, D. Palomino. 2020. Spatially Adaptive Intra Mode Pre-Selection for ERP 360 Video Coding. In 2020 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 2178-2182.

Z. Liu, P. Song, M. Zhang. 2019. A CU split early termination algorithm based KNN for 360-degree video. In Data Compression Conference(DCC). IEEE, 594–594.

B. Ray, J. Jung, M. C. Larabi. 2018. A low-complexity video encoder for equirectangular projected 360 video content. In 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP). IEEE, 1723–1727

Y. Wang, Y. Li, D. Yang, Z. Chen. 2017. A fast intraprediction algorithm for 360-degree equirectangular panoramic video. In 2017 IEEE Visual Communications and Image Processing (VCIP). IEEE, 1–4.

M. Zhang, X. Dong, Z. Liu, F. Mao, W. Yue. 2019. Fast intra algorithm based on texture characteristics for 360 videos. EURASIP Journal on Image and Video Processing 2019, 1 (2019), 1–16.

J. Chen, E. Alshina, G. Sullivan. J. R. Ohm, J. Boyce. Algorithm description of joint exploration model test model 3. JVET meeting document C1001, 1-30, 2016.