Encoding

When I first tested AV1 encoding back in August 2018 encoding times were glacial and seriously detracted from the potential usability of the codec. Table 1 from that story tells the tale. Unless otherwise indicated, all encoding times are on my HP ZBook notebook powered by a single 2.8 GHz Intel Xeon E3-1505M v5 CPU. In addition, LibVPx is the …

I frequently use the VMAF quality metric to analyze encoding parameters and compare codecs. In my experience, VMAF scores tend to match my own subjective quality observations and the fact that Netflix uses it gives the metric great credibility. Originally, there was only one VMAF version, but Netflix has added both a 4K model and a phone model, increasing the …

I’m writing a blog post on a free Netflix utility called VMAF-Master that you can download here (Windows executable here). Basically, it’s an open-source command line utility for computing VMAF, PSNR, SSIM, and MS SSIM on Linux and Mac computers with some enterprising contributors compiling a Windows version. One very well written help file relates to the models available under …

According to the last published statistics, in June 2017, Whatsapp users sent over 1 billion video messages a day. This obviously represents only a fraction of the market and daily traffic has certainly has grown since then. At the same time, 4K cameras have become standard and mobile screen resolutions have increased in size and quality, driving demand for higher …

I recently finished a streaming consulting project with AMC Networks and was pleased to receive the following LinkedIn recommendation from their VP of Video Products. It was great working with Greg and his team with the gorgeous content from AMC. Beyond this work with AMC, I’ve helped media companies and video publishers fine-tune their encoding parameters, modernize their encoding ladders, …

Moscow State University’s Video Quality Measurement Tool (VQMT) has been my go-to file analysis tool dating back to 2014 (see my initial review, here, and an update, here). As you can see in this video, version 11 of the tool adds several new features, including support for the VMAF 4K model, data rate graphs, and a results table. I’ve also …

Demuxed is the annual conference for video engineers by video engineers. Held on October 17 and 18 in San Francisco, the conference included 31 speakers giving talks in rapid-fire fashion ranging in duration from 10 to 30 minutes. To use a well-worn but appropriate metaphor, the experience is like drinking from a fire hose: almost impossible to comprehend and digest in …

Here’s the description; download handout below. T101. HOW-TO: Fine-Tuning Your Adaptive Encoding Groups With Objective Quality Metrics Tuesday, November 13: 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 exercise, with no way to really gauge the effectiveness and efficiency of the streams. However, by measuring stream …

W4. Encoding Live & VOD For HEVC/HLS Monday, November 12: 1:30 p.m. – 4:30 p.m. Apple’s support for HEVC in HLS is a groundbreaking event that opens up hundreds of millions of HEVC capable players. If supporting this spec is on your short-term development schedule, check out this workshop. The workshop starts by reviewing the new spec and sharing playback …

Zhi Li, senior software engineer at Netflix, recently co-wrote a paper entitled VMAF: The Journey Continues posted on the Netflix Technology Blog on Medium. After reviewing why VMAF was developed, how it’s been adopted in the industry, and some recent improvements, the paper discusses some best practices for using VMAF. In particular, this last section will be valuable to anyone who uses this …