【ffmpeg 命令行】android 调用ffmpeg+openh264 +filter

android 调用ffmpeg

• 参考
• 命令行调用

ffmpeg 调用openh264 编码

• crop

```cpp
 val cropFilter = "crop=${width}:${height}:${x}:${y}"

- 加入了filter 

```cpp
filter = "-filter:v $cropFilter -max_muxing_queue_size 512".split(" ")

• 输出

 val output = "-c:v libopenh264 -strict 2 ${o