Producing the chart above involved encoding 35 files using 5 different presets and then recording start and stop times. Since the files were about 20-seconds long, seconds were important. I’m sure a smarter compressionist than I could write a Python script to harvest the start and stop times but I do it by hand, which…
DetailsThis is a long post only of interest to those attempting to optimize their VP9 encodes. The three key takeaways are 1) use the command script shown on the bottom of the page, 2) a speed setting of 2 offers the optimal quality/performance tradeoff, and 3) the row-mt setting improves performance significantly with zero quality…
DetailsJust a quick note to let you know about some recent findings relating to the Netflix VMAF metric. By way of background, VMAF launched in June 2016 as the metric that powered Netflix’s per-title encoding engine, replacing PSNR. The fact that Netflix created and used VMAF gave the metric tremendous credibility and because Netflix open-sourced…
DetailsIn a previous lesson, I explored how to optimize quality on a webcam; this lesson tackles the audio side. Rather than simply discuss the various options I recorded multiple segments using the mics shown below so you can hear the difference. I shot all segments under the same conditions, in my office with fluorescent lights running,…
DetailsI spoke with Streaming Media Magazine’s Eric Schumacher-Rasmussen about the new course, Streaming Media 101: Technical Onboarding for Streaming Media Professionals. The video is available on YouTube so I embedded it below. If you’d rather read the transcript, click here to see the article on the Streaming Media website. Eric’s second question was “what’s…
DetailsI’m launching a new video course called Streaming Media 101: Technical Onboarding for Streaming Media Professionals. As the name suggests, the course teaches the technical background and skills necessary to successfully perform in a streaming-media related job, whether it’s producing and distributing video, or in a company creating the tools or services necessary to produce…
DetailsFor obvious reasons, a lot more of us will be presenting online over the next few months than ever before. This short video provides some simple techniques you can use to look your best. These images are from a book I published back in 2015 entitled Mastering Webcam and Smartphone Video: How to Look and…
DetailsThis 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…
DetailsThe 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…
DetailsThis article details how to use FFmpeg to benchmark decoder speed. Much of the info was derived from this FFmpeg Wiki. This article was updated to show results when the source file is played from a RAM drive and for additional definitions as reflected below. I just completed a consulting project that involved analyzing decoder…
Details
