Jan Ozer
August 21, 2020 Blogs, Encoding, Metrics
3,135
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. P.1203, which calculates the quality of HTTP Adaptive Streaming (HAS) …
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Jan Ozer
August 7, 2020 Blogs, FFmpeg, Learning
5,402
Note: This update details how to compute VMAF with FFmpeg on Windows. From my perspective, this feature has gotten progressively less usable and increasingly frustrating. Documentation is poor and the syntax is idiosyncratic and hard to use. If you have any alternative, like Moscow State University’s Video Quality Measurement Tool, I would spend the money and get something that works …
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Jan Ozer
July 29, 2020 Codecs, Encoding, News
2,669
Just a quick note to let you know that I’ve published a comprehensive report that documents the testing, quality, and performance of the Low Complexity Enhanced Video Codec (LCEVC) as developed by V-Nova and in the process of becoming standardized by MPEG. By way of background, I’ve been consulting with V-Nova to test LCEVC using a range of test files …
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Jan Ozer
July 28, 2020 Blogs, Codecs, Encoding, FFmpeg
3,080
Previous tests presented here showed that a Windows version of FFmpeg compiled by Zeranoe was about four times slower than a version compiled by a colleague who works in an OTT organization. Since then, Miguel Perez contacted the FFmpeg organization and Zeranoe, who researched the issue, recompiled, and created a new download that resolves the problem. To test the new …
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Jan Ozer
July 23, 2020 Blogs, Codecs, Encoding, FFmpeg
4,479
AV1 encoding on Windows is now only 2x slower than x265. With a properly compiled version of FFmpeg, encoding performance is slightly faster than the Alliance for Open Media’s encoder, though output quality is very slightly lower. Congrats to AOM for delivering on their promise to get encoding times down. Thanks for all the help I got from multiple sources, …
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Jan Ozer
July 22, 2020 Blogs, Codecs
3,128
AV1 encoding is now only 2x slower than x265. See the latest results here. Though FFmpeg took 50 minutes to produce a test file that both x264 and x265 encoded in about two minutes, the Alliance for Open Media’s aomenc encoder, running the same version of AV1 (version 2) produced the file in about 15 minutes. So FFmpeg’s slow AV1 …
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Jan Ozer
July 16, 2020 Blogs, Encoding, Metrics
2,005
Jan Ozer
July 13, 2020 Blogs, Metrics
998
Jan Ozer
July 13, 2020 Articles, Blogs, Learning, Other
1,514
My wife was watching a webinar for CME and there were two physicians with such picture perfect presentation that I just had to snap the image and comment. The list of what these two did right is lengthy and instructive. Both practiced perfect rule-of-thirds positioning, with their eyes about 1/3 down from the top of the frame. For this reason, their …
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Jan Ozer
July 10, 2020 Blogs, Codecs, Encoding
3,037
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 with FFmpeg 4.3, benchmarking x264, x265, and the latest version …
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