On Wed, Aug 12, 2015 at 11:03 PM, Robin Lery <robinl...@gmail.com> wrote: > I know about presets but faster presets lose the video quality. Are there > any hardware requirements I need to consider? Or are there any settings > that I need to tweak? And lastly where do I place the -threads flag to > encode video (before input or after input), I saw topics on thread but they > were confusing.
It's my experience that CRF more directly affects the quality, and presets more influence filesize and encoding speed; a preset of slow will be ABOUT the same quality as veryfast but the bitrate between the two would be drastically different (in my opinion and eyes). A comparison I found a while back is at http://mmmash.blogspot.com/2013/02/x264-settings-comparison-part-2-presets.html. There IS a noticable difference of the HD screen caps between the original and the ultrafast preset, but between original and veryfast, I don't see much of a difference. I've used -threads=1 successfully after input, before output file name. > > This is the command I am using now: > > ffmpeg -i input.mp4 \ > -codec:v libx264 -tune zerolatency -profile:v main -preset > medium -crf 23 -maxrate 1000k -bufsize 10000k -s hd720 -codec:a libfdk_aac > -pix_fmt yuv420p -movflags +faststart -threads 4 highoutput.mp4 \ > -codec:v libx264 -tune zerolatency -profile:v main -preset > medium -crf 23 -maxrate 500k -bufsize 5000k -s hd480 -codec:a libfdk_aac > -pix_fmt yuv420p -movflags +faststart -threads 4 lowoutput.mp4 > _______________________________________________ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/ffmpeg-user _______________________________________________ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-user