ffmpeg 视频质量下降

Question

一切都很好，但我的视频质量太低，这是我第一次使用 ffmpeg

这是我的命令

I/System.out: "-y" "-noautorotate" "-ss" "0" "-t" "31" "-i" "/storage/emulated/0/Download/20210227_175547.mp4" "-vf" "crop=w=3837:h=2160:x=1:y=-2070" "-r" "15" "-vcodec" "mpeg4" "-acodec" "copy" "-b:v" "2500k" "/storage/emulated/0/VEditor/VideoCroper/20210227_175547-0-13.mp4"

Answer 1

使用 libx264 而不是旧的 mpeg4:

I/System.out: "-y" "-noautorotate" "-ss" "0" "-t" "31" "-i" "/storage/emulated/0/Download/20210227_175547.mp4" "-vf" "crop=w=3837:h=2160:x=1:y=-2070" "-r" "15" "-vcodec" "libx264" "-crf" "23" "-acodec" "copy" "-movflags +faststart" "/storage/emulated/0/VEditor/VideoCroper/20210227_175547-0-13.mp4"

使用 -crf 选项控制质量。更多信息，请访问 FFmpeg Wiki: H.264。