Recent Posts

Comparing Fixed GOPs to Variable GOPs with I-Frames at Scene Changes

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 …

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Real-World Perspectives on Choosing the Optimal GOP Size

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 …

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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 …

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