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Old 12th April 2018, 21:37   #6021  |  Link
jlpsvk
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Join Date: Dec 2014
Posts: 240
Quote:
Originally Posted by Kavitha View Post
x265 has static levels of refinement(--refine inter <level>/refine intra <level>) which can be used with --analysis-reuse-level 10.
Efficiency in terms of quality increases as the levels of refinement increases. This quality increase results from additional computation thereby increasing the overall encoding time.
For a better quality-speed trade-off, dynamic refinement was introduced where the encoder dynamically switches between different inter refine levels.
This basically exploits the fact that not all CUs are required to be encoded with same level for better performance/quality.
Considering the complexity of video content and the analysis information from first pass, the encoder can intelligently decide the optimal level of refinement for each CU.
Intra frames are usually encoded with best quality as they are used as references by the consecutive frames. Hence error introduced in intra frames due to reusing analysis data can propagate to frames that use these intra frames as reference.
To minimize the chances of error propagation, refine-intra 4 (level with best quality) restricts reusing analysis data for intra frames and forces the encoder to perform full intra analysis in the second pass.
This is why x265 documentation suggests to use dynamic refinement along with refine-intra 4 and this setting is expected to give improved quality than other refine intra levels for some videos.
any suggested quality wise settings recommendation for 4K HDR encoding? with CRF ie 17?
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