I´m trying to use this ffmpeg command line on Android:

```
ffmpeg -i /sdcard/DCIM/video.mp4 -s 480x320 /sdcard/output.mp4

```

I have the executable file of ffmpeg (on this path: /data/local/tmp/ffmpeg/ with chmod 751), and as I read, I´m trying to invoke it using:

```
Runtime.getRuntime().exec("/data/local/tmp/ffmpeg -i /sdcard/DCIM/video.mp4 -s 480x320 /sdcard/output.mp4");

```

But I´m not getting any result after this calling, so I tried the same command but using the android terminal and I´m sure ffmpeg works because I ´m getting many outputs like video data. But it doesn´t do the action I want, I´m getting this message:

```
Unable to find a suitable output format for '/sdcard/output.mp4'

```

I don´t have any idea about what it can be the issue...
Thanks for help!!