Learning

This lesson teaches you how to compute VMAF with FFmpeg. It includes a download link to a specially compiled version of FFmpeg that can compute VMAF and to a zipped file that contains the batch files and input/output files shown in the lesson. I’m adding it as a lesson to my course Computing and Using Video Quality Metrics. If you’re …

The Common Media Application Format (CMAF) is supposed to be the Holy Grail of streaming; one set of files that you can deliver to multiple output points. How well does it work today? This 3:47 video shows you. I started by creating CMAF output in AWS Elemental MediaConvert. Why? Because they supply useful templates, have an easy to use UI, …

In a blog full of wonky compression articles, this could be the wonkiest article of all. If you’re not using capped CRF encoding, or considering the same, it’s almost certainly not of interest. If you are using capped CRF encoding (for constant rate factor), however, you almost certainly will find it interesting and perhaps even illuminating. A quick background note. …

It’s always good to review which articles readers found valuable over the past year to help focus on producing similar content in the future. By publishing the top ten, hopefully, those reading this article will see some articles they might find useful. So, without further ado, here were the top ten articles from the Streaming Learning Center blog in 2019. …

Author’s note: This is a very simple automation technique for FFmpeg beginners. I’m sure there are much more efficient ways to script this project, but this represents my baby steps in FFmpeg automation. I recently started a consulting project that involved encoding multiple files to multiple CRF values to create rate-distortion curves and BD-Rate computations. I’m testing three codecs with …

Any book author will tell you that while the revenue is nice, hearing from readers that find your book useful is even better. In this regard, I’m excited to blog about the following new five-star review of my book Encoding by the Numbers. What I tried to do in Encoding by the Numbers was to tie all configuration decisions to …

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 this to “everyone agrees that …

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 is usually a subjective, touchy-feely …

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 article covers these plus this …

A student of one of my courses recently asked, “I need a tool, which does the same job as BitrateViewer but for HEVC. Which tool do you use when you need to get some sort of a plot or just a list of bitrates per each second?” Great question. If you don’t know Bitrate Viewer, it’s a great way to …