android - ffmpeg 失去质量的视频

Question

一切都很好，但是我的视频质量太低了，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 控制质量选项。更多信息请访问 FFmpeg Wiki: H.264 .