for this file in no more than 30 minutes) and reducing file size by at least a half. Question: what ffmpeg parameters should I use to convert this input to MP4(H264/AAC) reasonably quickly (several times faster than actual rate, i.e. It's typical (or maybe even slightly worse than typical) VHS quality with interspersed blank screens for a few minutes (hence need for VBR).ĬPU is 4-core Inteal 3770K: MMX2 SSE2Fast SSSE3 SSE4.2 AVX The file is almost 4GB for less than 2 hours. You will need to add -strict experimental if using an old ffmpeg: the native FFmpeg AAC encoder used to be considered experimental but that is now no longer the case. After encoding it will move some info to the beginning of the file so it can begin playback quicker.
movflags +faststart is useful if your viewers will watch via progressive download. See FFmpeg Wiki: H.264 Video Encoding Guide. crf and -preset will allow you to adjust the output quality and encoding speed. It does not really matter with your input though since it is already yuv420p. This is better than cropping because simply covering it up avoids changing the aspect ratio: if that is not a concern the feel free to crop instead.įormat is added to use a widely compatible pixel format. You may have to adjust the height, or just remove it. Denoising can improve compressibility, but too much denoising will add noticeable blur.ĭrawbox in this example is is making a 6 pixel black box on the very bottom to mask any head switching noise. VHS can be noisy, so experiment with various values, and try without it too. Alternatively, you could try the w3fdif deinterlacing filter, but I haven't tested that one yet.
See the documentation and try out the different modes to see what looks best to you. crf 23 -preset medium -c:a aac -movflags +faststart \Įncoding form a VHS input can be improved with some filters: Encoding from a VHS source ffmpeg -i input -vf "yadif=1:1,hqdn3d=3,drawbox=y=ih-h:w=0:h=6:t=max,format=yuv420p" \
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