Video Encoding by the Numbers

Book excerpt: Video Encoding by the Numbers helps readers optimize the quality and efficiency of their streaming video by objectively detailing the impact of critical configuration options with industry-standard quality metrics like PSNR and SSIMplus. This takes the guesswork out of most encoding decisions and allows readers to achieve the optimal quality/data rate tradeoff. In addition, readers learn how to use tools like the Moscow University Video Quality Measurement tool, SSIMWave Quality of Experience Monitor, and FFmpeg to perform similar quality tests on their own videos. Because all videos encode differently, the tests detailed in the book involve eight different videos, including movie footage, animations, talking head footage, a music video, and Powerpoint and Camtasia-based videos. Readers first learn how to determine the ideal data rate for their videos at different resolutions. Then the book covers configuration options like bitrate control (CBR, VBR) that impacts quality and deliverability, and I-Frame, B-Frame, and reference frame decisions that impact quality and encoding time. The next three chapters focus on codec-specific configurations like Profile and preset for H.264 and HEVC, and the various configuration options available for Google's VP9. Next the book details how to choose an adaptive bitrate (ABR) technology, how to create an encoding ladder, and the most efficient ways to encode and package video into different ABR formats. Working off the groundbreaking work by Netflix and YouTube, the final chapter teaches the reader how a use per-title encoding with their own videos to create the ideal encoding ladder for each video in their library. Each chapter concludes with a section detailing how to configure the options discussed with FFmpeg, a preferred tool for high-volume video producers, including packaging into HLS and DASH formats (the latter with MP4Box). Overall readers learn how to optimally configure their encoding ladders and how to produce their videos with FFmpeg.