Netflix
Premium
HFR
HDR
GoP
K VMAF
PAR
DAR
Encoding Technologies
Aditya Mavlankar
Liwei Guo
Anush Moorthy
Anne AaronNetflix
QoE
Lishan Zhu
byWritten
GoP
10-bit
No matching tags
8-bit
No matching tags
As for HDR, our team is currently developing an HDR extension to VMAF, Netflix’s video quality metric, which will then be used to optimize the HDR streams.¹ The 8-bit stream profiles go up to 1080p resolution.For a sample of titles from the 4K collection, the following plots show the rate-quality comparison of the fixed-bitrate ladder and the optimized ladder. Various points are constrained to different codec levels, so receivers with different decoder level capabilities can stream the corresponding subset of points up to the corresponding level.The fixed-bitrate ladder often appears like steps — since it is not title adaptive it switches “late” to most encoding resolutions and as a result the quality stays flat within that resolution even with increasing bitrate. There exist higher bitrate points on the optimized ladder that deliver impeccable 4K quality, also for less bits compared to the fixed-bitrate ladder.Even before testing the new streams in the field, we observe the following advantages of the optimized ladders vs the fixed ladders, evaluated over 100 sample titles:At Netflix we perform A/B testing of encoding optimizations to detect any playback issues on client devices as well as gauge the benefits experienced by our members.
As said here by Netflix Technology Blog