diff --git a/README.md b/README.md
index 1da8536..20831f1 100644
--- a/README.md
+++ b/README.md
@@ -24,7 +24,8 @@ A library for convert PCM to tencent silk files.
 ### CLI
 
 ```shell
-ffmpeg -y -i $INPUT -acodec pcm_s16le -f s16le -ac 1 tmp.pcm
+# encode
+ffmpeg -y -i "$INPUT" -acodec pcm_s16le -f s16le -ac 1 tmp.pcm
 silk_codec pts -i tmp.pcm -s $HZ -o out.silk
 ```
 
@@ -41,6 +42,13 @@ Output #0, s16le, to 'pipe:':
                                    It is $HZ
 ```
 
+```shell
+# decode
+HZ=24000
+silk_codec stp -i "$INPUT" -o tmp.pcm -s $HZ
+ffmpeg -y -ar $HZ -f s16le -i tmp.pcm -o out.wav
+```
+
 ### Java
 
 [![Maven Central](https://img.shields.io/maven-central/v/io.github.kasukusakura/silk-codec.svg?label=Maven%20Central)](https://search.maven.org/search?q=g:%22io.github.kasukusakura%22%20AND%20a:%22silk-codec%22)