January, 2021

August, 2020

  • 21 August

    Introducing ITU-T Metrics P.1203 and P.1204

    While standards-based video codecs like H.264 and HEVC tend to dominate, standards-based video quality metrics have never risen to the same usage or attention level. With two innovative and highly accurate metrics now available from the ITU-T, this may change in the near term. Briefly, these models are: ITU-T Rec. …

July, 2020

June, 2020

April, 2020

  • 29 April

    Lesson of the Week: More Efficient Chart Title Creation in Excel

    I just finished one consulting project that involved testing 22 clips with three codecs to produce nine rate-distortion charts per clip (1080p, 720p, 480p for VMAF, SSIM, and PSNR) and am working another with 35 clips with 4 RD charts each with two encoding modes. So efficient chart creation in …

  • 17 April

    Tuning for Metrics: What About VMAF and VP9?

    If you’re comparing codecs with video quality metrics, you should consider tuning for that metric. However, x264 and x265 don’t have a VMAF tuning option. According to my analysis, it appears that tuning for PSNR is the best option and one you should strongly consider. When working with VP9, there’s …

  • 9 April

    Lesson of the Week: Accessing hr:min:sec Info in Chrome to Speed Data Entry

    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 …

  • 3 April

    VMAF is Hackable: What Now?

    Just 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 …