diff --git a/docs/ffmpeg.md b/docs/ffmpeg.md
index 46201db..c92c409 100644
--- a/docs/ffmpeg.md
+++ b/docs/ffmpeg.md
@@ -170,7 +170,10 @@ $ ffmpeg -r 1 -i input.m2v -r 24 output.avi
 <!--rehype:wrap-class=col-span-2-->
 
 ```bash
+# 从1分45秒开始剪切2分35秒
 $ ffmpeg -i <input> -ss 00:01:45 -t 00:02:35 -vcodec copy -acodec copy <output>
+# 从1分45秒开始剪切到第4分20秒，与上一行等效
+$ ffmpeg -i <input> -ss 00:01:45 -to 00:04:20 -codec copy <output>
 $ ffmpeg -ss 00:00:30 -i orginalfile.mpg -t 00:00:05 -vcodec copy -acodec copy newfile.mpg
 # 从 4.5 秒开始的 5 秒长的视频
 $ ffmpeg -i in.mp4 -ss 4.5 -t 5 out.mp4
@@ -588,4 +591,4 @@ ffmpeg -i 1.mp4 -b:v 548k -vf delogo=x=10:y=10:w=120:h=45:show=1 output.mp4
 - [FFmpeg Cheat Sheet](https://lzone.de/cheat-sheet/ffmpeg) _(lzone.de)_
 - [FFmpeg Cheat Sheet](https://devhints.io/ffmpeg) _(devhints.io)_
 - [FFmpeg Cheat Sheet](https://github.com/yuanqing/ffmpeg-cheatsheet) _(github.com)_
-- [FFmpeg Cheat Sheet](https://cheatography.com/thetartankilt/cheat-sheets/ffmpeg/) _(cheatography.com)_
\ No newline at end of file
+- [FFmpeg Cheat Sheet](https://cheatography.com/thetartankilt/cheat-sheets/ffmpeg/) _(cheatography.com)_