Posts about video quality metrics
Recently, video quality metrics have gotten a lot of hate, primarily from codec vendors. For example, yesterday on LinkedIn, respected Beamr CTO Dror Gill wrote, “everyone agrees that subjective (human) testing is the only accurate way to measure true perceptual quality.” After I pointed out industry support for using video quality metrics, Gill graciously changed…
My Streaming Media session on using video quality metrics is now available for replay immediately below. You can download the handout here. Here’s the session description. T101. HOW-TO: Fine-Tuning Your Encoding With Objective Quality Metrics Tuesday, November 19: 10:30 a.m. – 11:15 a.m. Choosing the number of streams in an adaptive group and configuring them…
The Moscow State University Video Quality Measurement Tool has long been my go-to desktop tool for computing video quality metric scores. When I created my course on Video Quality Metrics, I included six lessons on using the tool. Here’s a brief video that shows operation and the new features in Version 12. Lessons in…
Moscow State University’s Video Quality Measurement Tool (VQMT, $999 with volume discounts available) is my go-to desktop tool for computing metrics like VMAF, PSNR, and SSIM. The program is easy to use, has great visualization tools, and lets me inspect videos on a frame-by-frame basis. MSU recently released version 12 which has three great enhancements.This…
I had a 45-minute session at Streaming Media West 2019 entitled HOW-TO: Fine-Tuning Your Encoding With Objective Quality Metrics You can download the handout here. This version is about 200 MB because it contains three video demonstrations of the SSIMPLUS VOD Monitor and several other videos, but you’ll need Flash installed to run them (it’s…
A colleague asked for some resources relating to VMAF. Rather than answer in an email I thought I would create a post around it. Some of these are from Netflix, most from me (Jan Ozer). I’ve broken the items into three groups; Computing VMAF, Using VMAF, and About VMAF. I hope you find this collection useful.…
The Voronoi omnidirectional video metrics have the best correlation between test scores and subjective ratings than all measured 2D and 3D metrics according to its inventors. It’s an open-source metric you can download and learn to use below. I’ll be discussing the Voronoi metric in my upcoming talk on 2D and 3D video quality metrics…
One of the gaps in my online course on Video Quality Metrics and my upcoming course on metrics at Streaming Media West was the ability to compute VMAF using FFmpeg on Wind. I know it’s been possible for quite a while now but since I’m not a coder I can’t compile the version of FFmpeg…
I’m pulling together some materials for my pre-conference session at Streaming Media West (November 18-20 in Los Angeles) entitled Objective Quality Metrics 2D & 3D: What They Are, How To Compute Them, & How To Use Them. One lesson talks about “tuning” when encoding files to be measured with metrics like PSNR, VMAF, and SSIM.…
All codecs and encoding tools have a configuration option that controls the quality/encoding time tradeoff. With x264 (and x265) the preset controls that tradeoff. When choosing a preset you should consider 3 criteria: Overall quality – the overall quality produced by that preset Low frame quality – the quality of the lowest frame produced by…
