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16 December
Single-Pass vs Two-Pass VBR: Which is Better?

Let’s start this article with a quiz regarding how the quality and encoding speed of two-pass VBR (variable bitrate encoding) compares to single-pass VBR (that’s right, VBR in both cases). Choose the best answer. Two-pass takes twice as long as single-pass but delivers significantly better overall quality. Two-pass takes slightly longer than single-pass but delivers significantly better quality. Two-pass takes …
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3 December
Updated Lessons for Video Quality Metrics Course

We’ve updated several lessons in our Video Quality Metrics course, including some relating to the Moscow State University Video Quality Measurement Tool. The Moscow State University (MSU) Video Quality Measurement Tool (VQMT) is a tool that I use almost every day to analyze and compare encoded files. Our course, Computing and Using Video Quality Metrics: A Course for Encoding Professionals, …
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3 December
My FFmpeg-Related New Year’s Resolution: Document Before I Test

My typical workflow for testing-related articles and reports is to create the command string, run the tests, analyze the results, and then write or create the presentation. Since encoding is often so time-consuming, and I’m always in a hurry, I tend to quickly create the command strings with minimal thought, then run the tests, analyze the results, and start to …
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21 November
Transcoding UGC: ASICs Are the Lowest Cost Option

The predominant use for ASIC-based transcoders like NETINT’s Quadra Video Processing Unit (VPU) has been live transcoding for live 4K60P HDR streaming, cloud gaming, interactive video applications, and other high-volume applications. In this post, we explore using Quadra VPUs for large-scale VOD transcoding for applications like user-generated content sites and social media. As you probably know, both Meta and Google …
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21 November
Understanding the Economics of Transcoding

Whether your business model is FAST or subscription-based premium content, your success depends upon your ability to deliver a high-quality viewing experience while relentlessly reducing costs. Transcoding is one of the most expensive production-related costs and the ultimate determinant of video quality, so obviously plays a huge role on both sides of this equation. This article identifies the most relevant …
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16 November
The Impact of GOP Size on Video Quality

This freely downloadable report measures the qualitative impact of GOP sizes on animated, general entertainment, sports, and office footage for H.264 and HEVC. One of the most fundamental encoding decisions is GOP size or the frequency of I-frames in our encoded files. I-frames, also called keyframes, start each “group of pictures” comprised of I-, B-, and P-frames. Most of the …
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30 October
Free “Must-Have” Applications for Video Engineers

Here are the free “must-have” apps I install on every Windows computer (and three for-fee tools for deeper analysis). I just received a new Dell Precision 7820 server and had to prepare it for video transcoding and analysis. Here are the tools I installed to get up and running. I present the list and links first and then a list …
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19 October
Comparing CPUs, GPUs, and ASICs for High-Volume Transcoding

This case study compares CAPEX, power consumption, and co-location costs for GPU, CPU, and ASIC-based transcoding. This case study was derived from Ilya Mikhaelis‘ recent talk at NETINT’s symposium on Building Your Live Streaming Cloud. Images have been consolidated and modified slightly. You can view Ilya’s talk and download his slides here: bit.ly/vovs. Ilya Mikhaelis is the streaming backend tech …
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27 September
Learn To: Use Capped CRF with SVT-AV1 for Live Streaming

Learn to use Capped CRF with SVT-AV1 and FFmpeg for live transcoding, including how capped CRF compares to VBR and CBR. All tests and results are available in downloadable PDF. Capped CRF is an alternative to VBR and CBR that saves bandwidth on easy-to-encode sequences and preserves quality on hard-to-encode sequences. Our tests with SVT-AV1 and FFmpeg show: Performance: Capped …
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18 September
Best SVT-AV1 Bitrate Control Technique for Live Streaming

There are four bitrate control techniques worth considering for live encoding/transcoding using the SVT-AV1 codec. These are: Capped CRF VBR Capped VBR Constrained VBR Here’s what I found: Overall: Capped CRF shows promise with significant bitrate savings, good quality retention, and the best overall performance by ~10 – 25% (meaning more streams from the same hardware). VBR was generally the …
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