Unfortunately you can’t use -2 for both width and height, but if you already specified one dimension then using -2 is a simple solution. However, most non-FFmpeg based players can only properly decode 4:2:0, so that is why you often see ffmpeg commands with the -pix_fmt yuv420p option when outputting H.264 video. 4:2:2 would need “divisible by 2 for width”, and 4:4:4 does not have these restrictions. I have used the bicubic filter to do the up/down scaling.

If your source and destination videos are of the same dimensions. Also, learn about PSNR, SSIM, VMAF and how they are used for objective video evaluation. Same as above, but with a declared height instead leaving width to be dealt with by the filter:Īs required by x264, the “divisible by 2 for width and height” is needed for YUV 4:2:0 chroma subsampled outputs. Learn how to calculate PSNR, VMAF, SSIM using FFmpeg in this short tutorial. Set width to 1280, and height will automatically be calculated to preserve the aspect ratio, and the height will be divisible by 2: After that it will, however, make sure that the calculated dimension is divisible by n and adjust the value if necessary. If one of the values is -n with n > 1, the scale filter will also use a value that maintains the aspect ratio of the input image, calculated from the other specified dimension. If you would like to scale your video using FFMPEG you can do this by Just using -2įrom the FFMPEG scale filter documentation:

Ffmpeg scale down size