要设置输出纵横比,您可以使用 `-aspect' 选项,请参阅ffmpeg 文档。
-aspect[:stream_specifier] aspect (output,per-stream)’
Set the video display aspect ratio specified by aspect.
aspect can be a floating point number string, or a string of the form num:den, where num and den are the numerator and denominator of the aspect ratio. For example "4:3", "16:9", "1.3333", and "1.7777" are valid argument values.
If used together with ‘-vcodec copy’, it will affect the aspect ratio stored at container level, but not the aspect ratio stored in encoded frames, if it exists.