目前DSM已經更新到6.1.1
安裝ffmpeg套件
添加源，http://packages.synocommunity.com
支持的構架查詢
https://synocommunity.com/package/ffmpeg
https://github.com/SynoCommunity/spksrc/wiki/Architecture-per-Synology-model
或者直接下載手動安裝：
https://guillaume.smaha.net/syno/
比如我的216+II
就下載ffmpeg_braswell-6.0_3.1.2-2.spk
然後IPAD只用裝一個VLC就可以了，NAS可以實現轉碼，讓IPAD順利播放。
Install ffmpeg package to your Synology NAS
1. Go to the Package Center and click on Settings.
2. Click on ‘Package Sources’
3. Click ‘Add’ and enter the following details.
4. Click ‘OK’ to save your changes. Then click on ‘General’ tab and select ‘Any publisher’ in the Trust Level section.
5. From the Package Center, select Community tab on the left hand side and look for ffmpeg (If you can’t see the package you might need to hit the ‘Refresh’ button). Install ffmpeg by clicking on ‘Install’ button.
6. Click on ffmpeg and check if it’s running. If not, click on ‘Action’ and select ‘Run’.
來源
http://takopost.com/enable-synology-dts-transcoding-ffmpeg/