Metrics

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October, 2019

  • 14 October

    Choosing an x264 Preset

    All codecs and encoding tools have a configuration option that controls the quality/encoding time tradeoff. With x264 (and x265) the preset controls that tradeoff. When choosing a preset you should consider 3 criteria: Overall quality – the overall quality produced by that preset Low frame quality – the quality of …

  • 6 October

    Here’s What I’m Teaching at Streaming Media West Next Month

    Streaming Media West is coming up next month in the City of Los Angeles (as opposed to Huntington Beach where it’s been the last few years). Specifically, it’s at the Westin Bonaventure on November 19-20 (Tuesday/Wednesday) with pre-conference sessions on Monday the 18th. I’ll be my normal busy self with …

  • 4 October

    Creating a Unique Encoding Ladder for Smartphone Viewers

    Many producers distribute the same encoding ladder to all viewers. However, sending a 1080p stream to smartphone viewers may be a waste of bandwidth as both SSIMPLUS and VMAF scores reveal that lower resolution, lower-bandwidth videos deliver similar quality at a lower cost. This tutorial, from my course Computing and …

June, 2019

  • 24 June

    MSU VQMT Gets Auto-Scaling But Watch the Scaling Algorithm

    One of the first operations I learned in FFmpeg was how to scale subsampled video files back to the source resolution to compute PSNR in the Moscow State University (MSU) Video Quality Measurement Tool (VQMT). Thankfully, for those not familiar with FFmpeg, as of VQMT version 11.1, this operation is …

May, 2019

  • 27 May

    The Evolving Encoding Ladder: What You Need to Know

    This article discusses the evolution of the encoding ladder from the fixed ladder presented by Apple in Tech Note TN2224 to context-aware-encoding, which creates a ladder that not only considers the encoding complexity of the content, but also the producer’s QoE and QoS metrics. The encoding ladder embodies the most …

January, 2017

  • 17 January

    Choosing the Data Rate for your Mezzanine Files

    (Note: This article was amended to show the comparative results at 6 mbps) Summary (The MPD) As more and more producers move their encoding to the cloud, or distributing via OVPs or other service providers, the data rate for the mezzanine files is significant factor for upload time and bandwidth …