Codecs

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July, 2020

  • 10 July

    Promising Initial Results with AV1 Testing

    AV1 encoding is now only 2x slower than x265. See the latest results here.  I began testing AV1 early this week. Briefly, my tests involve 16 ten-second clips in four genres (movies, sports, animations, gaming) and an “other” category (music video, nature video). I’ve completed the first set of tests …

  • 9 July

    Compressionists: You’re Only as Good as Your Tools

    I’m reviewing AV1 encoders for Streaming Media Magazine and was performing some QC on the AV1 files that I produced with the latest version of FFmpeg. Two file details I always check are GOP size and whether the GOPs are closed or not. I check these for multiple reasons.

  • 5 July

    Choosing the Optimal Preset for AV1 Encoding (and Other Questions)

    AV1 encoding is now only 2x slower than x265. See the latest results here.  I’m comparing AV1 encoders for Streaming Media Magazine. I plan to include codecs from: The Alliance for Open Media (hopefully versions 1.0/2.0) Visionular Intel Mozilla (Mozilla is out – didn’t respond to my inquiry). If there …

June, 2020

  • 24 June

    Apple TV Finally Supports 4K YouTube Files in AV1 or VP9 (Maybe Both?)

    On its preview page for Apple TV 4K, Apple announced that the update to tvOS 14, which is expected to ship this fall, will support “YouTube videos in their full 4K glory.” By way of background, YouTube produces most 1080p videos using H.264 which plays everywhere but produces larger resolutions …

  • 15 June

    Preliminary VMAF and PSNR Scores for New Xilinx Transcoding Appliances

    Live streaming at scale is the perfect application for hardware transcoders that deliver highly-affordable encoding density. Xilinx just announced a series of transcoding appliances targeting these live streaming use cases built around the new Xilinx Real-Time (RT) Server reference architecture. I’ve been benchmarking output quality with two card-based encoders deployed …

May, 2020

  • 24 May

    Smart TVs with AV1 Support Now Shipping

    Many 2021 model Smart TVs support AV1 decoding, making it a good time to start thinking about how to encode AV1 videos. A great way to start is our course Encoding with the AV1 Codec, which details how to encode AV1 encoded video with FFmpeg (libaom-av1), the Alliance for Open …

  • 22 May

    AV1 Turns 2.0

    Just a quick announcement that the Alliance for Open Media has launched version 2.0 of the AOMedia AV1 encoder that you can download here. According to the Phoronix website, from which I grabbed this news: “Libaom 2.0 is the first release since the original 1.0 release back in mid-2018 after …

  • 5 May

    Lesson of the Week: Codecs are Not Generic

    I discuss the bandwidth savings delivered by VP9 and HEVC over H264 in my course Streaming Media 101: Technical Onboarding for Streaming Media Professionals. I wanted to illustrate this with my own tests, so I used FFmpeg to encode H.264, HEVC, and VP9 output using about 25 short test files. …

April, 2020

  • 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

    Encoding VP9 in FFmpeg: An Update

    This is a long post only of interest to those attempting to optimize their VP9 encodes. The three key takeaways are 1) use the command script shown on the bottom of the page, 2) a speed setting of 2 offers the optimal quality/performance tradeoff, and 3) the row-mt setting improves …