ffmpeg -ss 0 -t 8 -i input.mp4 -acodec copy -vcodec copy output.mp4
可以设置编解码器。但是，要过滤：
ffmpeg -i input.mp4 -vf crop=100:100:0:0 output.mp4
如果合并：
Filtergraph 'crop=100:100:0:0' was defined for video output stream 0:0 but codec copy was selected.
Filtering and streamcopy cannot be used together.
如何像时间剪辑一样设置编解码器？
ffmpeg ×1