This is a known issue that can occur when the iPad detects an external display connection via a KVM switch. When the KVM switch is connected, iPadOS may change the video output mode or allocate resources differently, which can interfere with the Emby app's video decoding pipeline. Here are steps to resolve it:
1. Check Emby playback settings with KVM connected:
- Open Emby app > Settings > Playback
- Try switching the video player from "Native" to "VLC" or vice versa
- Reduce the maximum bitrate/quality setting when using the KVM switch
2. Disable hardware decoding in Emby:
- Go to Emby app Settings > Playback > Video Player settings
- Disable hardware acceleration/decoding
- This forces software decoding which is more compatible with external display setups
3. Try Direct Play vs Transcoding:
- In Emby settings, enable server-side transcoding for your iPad
- This offloads the processing to your Synology NAS instead of the iPad
4. Check KVM switch compatibility:
- Some KVM switches that don't fully support USB-C DisplayPort Alt Mode can cause the iPad to misidentify the output device
- Try a different cable between the KVM and iPad if possible
5. Update Emby app and iPadOS to latest versions, as this type of external display handling bug may have been patched.
If transcoding via Synology resolves the playback issue, the root cause is likely the iPad's hardware video decoder conflicting with the external display signal from the KVM switch.
