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A New R-D Optimization Criterion for Fast Mode Decision Algorithms in Video Coding and Transrating

Tutkimustuotosvertaisarvioitu

Yksityiskohdat

AlkuperäiskieliEnglanti
Sivut696-710
JulkaisuIEEE Transactions on Circuits and Systems for Video Technology
Vuosikerta26
Numero4
DOI - pysyväislinkit
TilaJulkaistu - 2015
OKM-julkaisutyyppiA1 Alkuperäisartikkeli

Tiivistelmä

Mode decision has a significant effect on the quality and complexity of video coding. It is even more challenging when generating multiple bitstreams with different bitrates in, for example, Dynamic Adaptive Streaming for HTTP (DASH) or transrating systems. Full search and simplified fast search mode decision methods either suffer from a high computational complexity or have a negative impact on quality. Furthermore, mode selection in conventional approaches strongly depends on the quantization parameter. Hence, modes that have been selected for high bitrate compression may not be suitable for low bitrate when transrating a bitstream. In this paper, we propose a Rate-Distortion (R-D) optimized criterion for fast mode decision algorithms. The proposed cost function when adopted in different fast mode decision algorithms, not only improves the R-D performance by up to 6.6% in terms of Bjøntegaard delta rate, but also reduces the execution time of the encoder by up to 6.8%. We also show that modes selected by the proposed criterion are less sensitive to changes in bitrate or quantization parameter. As a result, the same modes in an encoded bitstream may be used even after transrating using re-quantization, resulting in a significant R-D performance improvement of up to 33.3%.

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