FFMpeg 结合了两个单独的命令

Question

我正在运行 2 个单独的 ffmpeg 命令..

ffmpeg -i video.mp4 -vf scale=1024:768 -crf 0 output_video.mp4

ffmpeg -i output_video.mp4 -s 640x360 -c:v libx264 -preset slow -b:v 650k -r 24 -x264opts keyint=48:min-keyint=48:no-scenecut -profile:v main -preset fast -movflags +faststart -c:a libfdk_aac -b:a 128k -ac 2 out-low.mp4

有没有办法一次完成这两个命令？试图避免 2 次编码 session 降低质量

Answer 1

标记过滤器输出并在 -map 中引用它们选项:

ffmpeg -i video.mp4 -filter_complex "[0:v]scale=1024:768[v768];[0:v]scale=640:360[v360]"
  -map "[v768]" -map 0:a -c:v libx264 -c:a copy -crf 0 output_video.mp4
  -map "[v360]" -map 0:a -c:v libx264 -preset slow -b:v 650k -r 24 -x264opts keyint=48:min-keyint=48:no-scenecut -profile:v main -preset fast -movflags +faststart -c:a libfdk_aac -b:a 128k -ac 2 out-low.mp4