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In a recent white paper titled Bi-Directional Deep Contextual Video Compression (DCVC-B), researchers Xihua Sheng, Li Li, Dong Liu, and Shiqi Wang proposed a new approach to enhancing B-frame compression for video encoding. The authors assert that their scheme “achieves an average reduction of 26.6% in BD-Rate compared to the reference software for H.265/HEVC under random access conditions” and even …

A new AI-based codec proved 18% more efficient than VVC but substantial decoding requirements will limit short-term commercial application. Here’s a summary of the white paper.  In December 2024, researchers from Fudan University introduced M3-CVC, an AI-based video compression framework that combines large multimodal models (LMMs) for semantic understanding and conditional diffusion models (CDMs) for high-fidelity reconstruction. The framework employs …

I first encountered the line, “Anything worth doing is worth overdoing,” in the Robert Heinlein novel Time Enough for Love. I bring this up because this is my third recent article on GOP size, and I think I’m close to beating this topic into the ground. I’ll let you be the judge. To recount, I reported on testing in an …

One of the most fundamental encoding decisions is the size of the Group of Pictures (GOP) or the frequency of I-frames within an encoded file. I-frames, also known as keyframes, are the starting points for groups of pictures, consisting of I-, B-, and P-frames. Traditionally, the GOP size is directed by adaptive bitrate streaming considerations, such as ensuring an I-frame …

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 …

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 …

Learn how thread count impacts video quality, encoding speed, and costs in FFmpeg workflows. Master configurations for optimal production and testing results.

Though I work primarily on Windows computers, I also have several Macs. Here are the Mac video Apps I use on them and other Mac tools you should consider. Free or Almost Free MediaInfo ($0.99) Platform: Mac, Windows, Linux Description: MediaInfo is an essential tool that displays technical and tag data for video and audio files. Free and cross-platform, this …

When choosing a preset for VOD transcoding, it almost always makes sense to use the highest-quality preset, because any increase in encoding costs will typically be recouped via bandwidth savings delivered by the more efficient encoding. I covered that analysis in detail here. Note that this conclusion assumes that you deliver at a certain quality level and will boost the …

I was reminded of this recently as I prepared for a talk on AV1 readiness at the upcoming United Cloud Tech Talk. Though quality is only a single factor, I wanted to nail the quality comparisons for the talk, but didn’t have time to produce all the iterations myself. It’s been a while since I benchmarked H.264, HEVC, AV1, and …