Computing and Using Video Quality Metrics: A Course for Encoding Professionals
This course will teach you how to choose and use video quality metrics like VMAF, SSIMPLUS, PSNR, and SSIM.
Jan provides a great overview of the different video quality metrics, a breakdown of different tools used to measure PSNR, SSIM and VMAF and supports that wi...
Read MoreJan provides a great overview of the different video quality metrics, a breakdown of different tools used to measure PSNR, SSIM and VMAF and supports that with practical examples including tips and tricks he uses for analysis and reporting.
Read LessMe pareció muy interesante y muy complejo.
Me pareció muy interesante y muy complejo.
Read LessJan Ozer here. I’ve been compressing video since around 1993. For most of that time, all encoding decisions and recommendations were largely opinion-based. Sure, you tested the parameters and scrutinized the output, but subjective opinions are just so .. subjective.
Then I learned how to compute objective metrics like PSNR, SSIM, and VMAF, which inspired me to write Video Encoding by the Numbers: How to Eliminate the Guesswork from Your Streaming Video. The book evaluates dozens of codecs and encoding configuration options, and every recommendation is based on metric scores; in the words of one Amazon reviewer, transforming “alchemy into science.”
As a video encoding professional, you should approach encoding and configuration decisions the same way. Choosing a preset for your codec or encoder? Run some test encodes, time the results, and measure quality. Then you’ll know exactly what the quality/encoding cost tradeoff is.
Evaluating a new codec? Run BD-Rate comparisons, or better yet, weighed average computations and compute the precise impact a new codec will have on your bandwidth cost and viewer QoE.
This course teaches you how, so you can eliminate the guesswork from your encoding decisions.
Encoding professionals who want to optimize their encoding ladders and encoding configurations
Encoding professionals who want to quantity the benefits of adopting a new codec
Researchers seeking to produce and interpret BD-Rate computations and Rate-Distortion Curves
The pros and cons of common metrics like VMAF, PSNR, SSIMPLUS, Apple AVQT, and SSIM
How to compute these metrics and interpret the scores
How to create rate distortion curves and compute BD-Rate functions for internal decision making or articles and presentations
How to compute weighted average bandwidth savings and quality impact to determine true benefits of adopting a new codec
How to use these results to make decisions like choosing the optimal encoding parameters or preset, building an encoding ladder, and choosing an encoder
How to use tools like the Moscow State University Video Quality Metric Tool, SSIMPLUS VOD Inspector, Hybrik Media Analyzer, and FFmpeg to compute these metrics
Metric Overview
Comparing Objective Metrics
Using Metrics - In General (Going Beyond the Number)
Introduction to Rate Distortion Curves and BD-Rate Functions
Introduction to Weighted Average Bandwidth and Quality Computations
Introduction to Netflix's VMAF
FREE PREVIEWIntroduction to SSIMPlus
Introduction to PSNR
Introduction to SSIM
Introduction to the Apple Advanced Video Quality Tool (AVQT)
Selecting and Preparing Test Files
Encoding Your Clips for General Testing
Encoding for Rate Distortion Curves and BD-Rate Functions
FREE PREVIEWTuning for Metrics
Create Same Resolution YUV or Y4M For Testing
FREE PREVIEWScale to Source Resolution YUV or Y4M For Testing
Create 30p Source from 60p Source
Converting YUV Files to Y4M Format
Compute PSNR With FFmpeg During and After Encoding
Compute SSIM With FFmpeg
Compute VMAF With FFmpeg
VQMT Overview - Loading Files and Configuring the Metrics
FREE PREVIEWVMQT Overview - Analyzing the Results
Choosing and Configuring Metrics
Load Files Into MSU VQMT
Running Multiple VQMT Instances
Fixing Out-Of-Sync Videos in the GUI and Command Line
Command Line Operation
Intro to FFMetrics and Getting Up and Running
Accessing FFMetrics Results Files
FFMetrics - Command Line Operation
Running FFMetrics
Microsoft Excel: Producing Rate Distortion Curves
Producing BD-Rate Functions
Efficient Chart Title Creation in Excel
Computing Weighted Average Bandwidth Savings and Quality Impact
Choosing The Best Bitrate Control Technique
FREE PREVIEWLesson: Choosing an x264 Preset
Per-Title Encoding
Per-Category Encoding
Choose Best Codec For Live Transcoding
Overview
FREE PREVIEWLoading Files and Selecting Tests in the GUI
Downloading and Viewing Results in the GUI
Jan Ozer
Jan is a recognized expert in streaming media who has tested codecs since 1993 (not a misprint) and has taught in-person and online courses on video and streaming production since 1995.
Jan is a contributing editor to Streaming Media Magazine, where he tests and reports on codecs, encoders, and related products and services. Jan has authored multiple books on streaming production, including Video Encoding by the Numbers: Eliminate the Guesswork from your Streaming Video and Learn to Produce Video with FFmpeg in 30 Minutes or Less.
Besides these courses, Ozer teaches workshops at Streaming Media online and in-person events. Overall, the Streaming Learning Center has served over 4000 students from some of the biggest names in streaming video.