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Kvazaar HEVC encoder for Efficient Intra Coding

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review


Original languageEnglish
Title of host publicationProceedings of the IEEE International Symposium on Circuits and Systems, IEEE ISCAS, Lisbon, Portugal, May 24-27, 2015
Number of pages4
ISBN (Print)9781479983919
Publication statusPublished - 2015
Publication typeA4 Article in a conference publication
EventIEEE International Symposium on Circuits and Systems -
Duration: 1 Jan 1900 → …


ConferenceIEEE International Symposium on Circuits and Systems
Period1/01/00 → …


This paper presents an open-source Kvazaar encoder for HEVC intra coding. This academic software encoder has been developed from the scratch using C as an implementation language by prioritizing modularity, portability, and readability of the source code. Kvazaar implements almost the same intra coding functionality as HEVC reference encoder (HM) but its rewritten source code makes it significantly faster. In all-intra (AI) coding, a single-threaded C implementation of Kvazaar is 2.3 times faster than HM at a cost of 1.7% bit rate increase. The respective values with a high speed preset of Kvazaar are 10.6 and 8.8%. Compared to a single-threaded C++ implementation of x265, Kvazaar improves rate-distortion performance and increases encoding speed in both high-quality and high-speed test cases. Kvazaar has a particular edge in the high-speed test case where it almost halves the BD-rate loss and more than doubles the performance.

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