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x264 preset reference
x264 is well documented, and I like using it, but sometimes I want to see all the flags that a preset is using, compared to the defaults. So, I put this little table together to work as a reference. I used mediainfo to read the x264 encoding options from the video. Since x264 doesn't write *all* of the encoding settings (that I can see, partitions is an example), this may not be 100% accurate.
You can duplicate my results if you like. The source video was nyan cat jazz, which I downloaded using youtube-dl, converted to YUV4MPEG2 using libav, then used x264 encoder to encode the raw video into a Matroska container.
$ youtube-dl http://www.youtube.com/watch?v=AaEmCFiNqP0 # start at 15 seconds, encode 5 seconds, ignore audio $ avconv -i AaEmCFiNqP0.flv -ss 15 -t 5 -an video.y4m $ x264 --preset ultrafast -o x264_preset_ultrafast.mkv video.y4m $ mediainfo x264_preset_ultrafast.mkv