Playback error on Chrome/Edge browsers

[TheDreadPirate]

You haven't enabled hardware acceleration.

Select Intel Quick Sync from the drop down. Check all the codec boxes except AV1. Enable hardware encoding. Do NOT uncheck low power encoding. Allow encoding in HEVC format, but NOT AV1.

Do not enable VPP tone mapping or tone mapping. The Linux kernel in most Synology NASes is pretty old, probably 4.4.X. Intel deprecated support for that kernel in their OpenCL drive, which was required for tone mapping.

Scroll all the way down and check "Throttle transcodes" and "Delete segments".

Save.