HDR-VMAF aims to measure perceptual quality of HDR streams and ignores display mapping. A/B testing with DO encodes and optimizing entire HDR catalog by 2023. Results show 58% reduction in storage space needed compared to fixed ladder encoding.
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Quadra VPU is an ASIC-based transcoder for 4K60P HDR streaming. Tests reveal Quadra can replace 46 server CPUs and consume 22% less resources than general-purpose CPUs & GPUs. Results show Quadra outperforms x264 for UGC quality levels, achieving a maximum VMAF score of 91.82 and throughput of 169 sec/hr.
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Get the free report to help you choose between H.264 and HEVC GOP sizes – from 1/2 to 20 seconds – to optimize quality for any type of footage: animation, entertainment, sports, or office. Quickly learn which GOP size is best with the help of VMAF metrics.
Read MoreA new image-content independent measurement method has been developed for determining video resolution. Factors such as noise and grain are discussed, along with steps from imaging to display device. This enables evaluation of VMAF by considering true measured resolution. Video noise management helps reduce bitrate and Film Grain Synthesis can provide a film look far beyond standards. Denoising should deliver high quality results to avoid masking low resolution artefacts.A new image-content independent measurement method has been developed for determining video resolution. Factors such as noise and grain are discussed, along with steps from imaging to display device. This enables evaluation of VMAF by considering true measured resolution. Video noise management helps reduce bitrate and Film Grain Synthesis can provide a film look far beyond standards. Denoising should deliver high quality results to avoid masking low resolution artefacts.
Read MoreVMAF source code, precompiled Windows code and models for 1080p available on Github. FFmpeg full version with libvmaf must be used to compute scores and add PSNR to logfile.
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SVT-AV1 is a video codec that provides quality compression with fast encryption. This experiment tested speed vs quality tradeoffs by varying CRF values and presets in FFmpeg. Results reveal preset 8-12 are best for fast encoding while preset 2-4 produce high-quality video but take longer. Adjusting these parameters allows users to customize their encoding settings to suit their specific needs.
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To choose the optimal x264 preset, you have to balance encoding and distribution costs. This article shows you how. Over the last few years, I’ve used the first chart below to represent the tradeoffs associated with different presets and help readers (or listeners) choose a preset. To create the chart, you encode your test files to standard parameters using all the presets, measuring encoding time. Then you verify that the bitrates are similar, and then compute VMAF and low-frame VMAF on all the files. Low-frame VMAF is the lowest VMAF score for any frame in the video, an indicator of transient quality problems. Presets and Quality Then you average the scores and plot the results. The horizontal axis contains all the presets. The blue line is the percentage of encoding time each preset takes as compared to the placebo. The red line is the harmonic mean VMAF, and the green line is the low-frame VMAF. This chart illustrates the quality/encoding time tradeoffs associated with…
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Video Multimethod Assessment Fusion (VMAF) is an industry-standard video quality assessment tool created by Netflix that offers a combination of algorithms for objectively measuring video quality. It produces a single score based on a variety of factors, such as contrast, color gamut, sharpness, and
Read MoreThis article shows the quality/encoding time tradeoffs for producers choosing a preset for SVT-AV1 and libaom-AV1. In this case, libaom-AV1 preset 0 takes the longest to encode but delivers the best VMAF and low-frame quality,...
Read MoreAbst ract: In live streaming applications, typically a fixed set of bitrate-resolution pairs (known as a bitrate ladder) is used during the entire streaming session in order to avoid the additional latency to find scene...
Read MoreFor years I’ve underlined that even a useful metric like VMAF was not able to efficiently identify banding and that we needed something more specific or a metric like VMAF but more sensible to artifacts in dark or flat parts of...
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