ubuntu ffmpeg 转码错误

[aac @ 0xde2400] The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.

报错 错误提示
The encoder 'aac' is experimental but experimental codecs are not enabled, add '-strict -2' if you want to use it.

正确处理

ffmpeg -i 正义联盟.HD.720p.中英双字幕.rmvb -strict -2  正义联盟.HD.720p.中英双字幕.mp4

p.p1 { margin: 0; font: 11px Menlo; color: rgba(0, 0, 0, 1); background-color: rgba(255, 255, 255, 1) }
span.s1 { font-variant-ligatures: no-common-ligatures }