I've broken Periscope

Hello,

I've managed to start broadcasting and watch the broadcast in a browser window. But the Periscope app on iOs crashes every time I try to play the broadcast.

Here is how I use `ffmpeg`:

```
ffmpeg -re -i s.mp4 -c copy -s 568x320 -f flv rtmp://...
```

Should I convert my videos to some format before I stream them? Or maybe my `ffmpeg` settings are wrong?

Thank you in advance
