If you’re optimizing x265 for speed, enabling Wavefront Parallel Processing (WPP) looks like a no-brainer. Table 1 shows a staggering 7.3x improvement in encoding time. A 3:15 encode with WPP turns into a painful 23:51 without it. The quality penalty? Negligible. VMAF drops just 0.19, with the low-frame VMAF off by only 0.77 (low-frame is the lowest VMAF score of …
Read More »Search Results for: x265
Three Things to Know About 2-Pass x265 Encoding
Here are three things to know about 2-pass x265 encoding with FFmpeg. If you’re using -pass 1 and -pass 2 in your command string, it’s probably not working. You must use x265-params 0:pass=1 and then x265-params 0:pass=2 in the second pass. In the way we absolutely love about FFmpeg, there’s no error message if you use -pass 1/-pass 2; it …
Read More »What’s the Best Setting for x265 Two-Pass Encoding?
I’m running some 1-pass vs. 2-pass comparison testing with x265. Unlike with x264 (see tests here), there’s a substantial performance penalty for running 2-pass with minimal quality benefit. I tried the no-slow-firstpass=1 setting, which only accelerated two-pass by about 14%. Here are the results from a single test file. I don’t want to process them all if there’s a magic …
Read More »How to Optimize x264 and x265 Quality in FFmpeg
This blog includes the video and handout from my talk on “How to Produce x264 and x265 Video at Maximum Quality and Maximum Efficiency” at NAB 2023 (thanks to Dan Rayburn). Here’s the description. This research-based session explores configuration options like presets, threads, color depth, and others that impact output quality and encoding efficiency. Balancing encoding cost and streaming bandwidth, …
Read More »Ozer to Present on x265 Encoding and Packaging at Mile-High Video
You can download the presentation handout here (download). I’ll add the video once it becomes available. I’m thrilled to speak at Mile-High Video in Denver, which runs from May 7 – 10 2023. My presentation is on Sunday, May 7, entitled, “Encoding and Packaging x265/HDR with FFmpeg, Bento4 and mp4box.” The description is, “this introductory session will cover the basics …
Read More »Choosing an x265 Preset: an ROI Analysis
This post presents a return on investment view of choosing an x265 preset that delivers the optimal blend of encoding cost and storage and bandwidth savings. The first chart, x265 Encoding Time/Quality Tradeoff, is from a lesson in my course Streaming Media 101: Technical Onboarding for Streaming Media Professionals. Given the bandwidth and storage savings that higher-quality x265 presets deliver, …
Read More »AV1 Now Only 2X Slower Than x265
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, …
Read More »Telestream Helps Launch Open Source x265/HEVC Project
This week, Telestream announced the availability of an open source H.265 (HEVC) encoder, co-founded and managed by MulticoreWare Inc. I had a chance to speak with Telestream CTO Shawn Carnahan about the venture.
Read More »Codecs for CFOs
Executive Summary The H.264 codec has proven remarkably durable, but demand for 4K efficiency, HDR compatibility, and small-screen/low-bitrate quality makes adopting advanced codecs like VP9, HEVC, AV1, and VVC inevitable for most services. However, between 2022 and 2026, the economics of streaming codecs have changed materially. Tier‑1 OTT services that once paid $100K in H.264 content royalties may now pay …
Read More »Comparing H.264, HEVC, VP9, and AV1 in SBE: From BD-Rate to Contextual ROI
Most video engineers use a similar tool stack. MediaInfo for file data, Bitrate Viewer to view the bitrate of H.264-encoded files on Windows, Moscow State University VQMT on Windows for metrics, with a custom combination of data input scripts and Excel for RD curves and BD-Rate data. Most tools have critical gaps. Few let you compare videos during real-time playback, …
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