Advanced settings reference

Settings → Advanced, behind a warning banner.

Two things to know before you touch anything:

• Every default is exactly what the server does anyway. Opening this section and changing nothing changes nothing. There is no hidden “make it good” setting you are missing out on.
• Every field shows where its value came from (default, an environment variable, or something you set) and has a Reset that puts it back.

Most fields apply to new playback sessions, so a stream already running finishes on the old value. The few that need a restart say so on the field itself.

Everywhere below, 0 or blank means automatic.

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Transcoding

What happens when a device cannot play a file as it is and the server has to re-encode it live.

Setting	Default	Range	What it does
Encoder quality	Balanced	Speed, Balanced, Quality	The preset handed to the encoder. Speed uses less processor for a slightly worse picture at the same bitrate; Quality is the reverse. On a machine with a hardware encoder this costs less than you would think
Encoder pacing	4	1 to 16, 0 unlimited	How much faster than real time the server is allowed to encode. Encoding at 4x means it stays comfortably ahead of a viewer without burning the processor building an hour of buffer nobody will watch. Raise it if seeking feels sluggish; lower it on a machine doing other work
Initial burst	20 s	5 to 300	How many seconds it encodes at full speed before pacing kicks in. This is what makes playback start instantly. Raise it if playback starts but stutters in the first few seconds
Segment duration	4 s	2 to 10	How the stream is chopped up. Shorter starts faster and seeks more precisely; longer is more efficient and steadier over a poor connection
Threads per transcode	Auto	0 to 64	Processor threads for one software encode. Auto uses what is available. Set it to leave headroom for something else on the machine
Process priority	Normal	Normal, Below normal, Low	How the operating system schedules the encoder. On a machine you also use for something else, set this to Below normal. Encoding then gets out of the way instead of making everything else sticky
Max simultaneous transcodes	Unlimited	0 to 20	A hard ceiling on live re-encodes. At the limit, a new one is refused with a message saying the server is busy rather than being queued behind a spinner or silently degraded. Files that play directly, and files that only need a container swap, always start regardless: they cost almost nothing
Hardware decode	On	On, off	Whether the graphics chip decodes as well as encodes. Leave it on. Turn it off if a specific file glitches or fails, which usually means a driver bug
Encoder backend	Auto	Auto, NVENC, QuickSync, AMF, VAAPI, VideoToolbox, Software	Auto probes what the machine has with a real test encode and picks the best. Force one only when you are diagnosing something. If a forced backend does not actually work, the server falls back to software and says so on the About page. Needs a restart
HDR output	Preserve	Preserve, Tone map	Preserve sends HDR untouched to devices that can take it, and maps it down only for devices that cannot. Tone map maps it down always, which is the answer when your HDR TV is producing a washed-out picture
Tone-map algorithm	Hable	Hable, Reinhard, Mobius, Clip, Linear, Gamma	How HDR is squeezed into a normal range when it has to be. Hable protects highlights; Reinhard is flatter; the others exist because taste varies
Scratch folder	Data directory	Any writable folder	Where in-progress transcode segments are written. Point it at a fast disk, or at a RAM disk if you have memory to spare. Never a network share. Needs a restart
Idle stream timeout	3 min	1 to 60	How long a stream nobody is fetching is kept before its encoder is stopped. This is what reclaims a session when somebody pauses and wanders off
Downmix volume boost	1.0 (none)	1.0 to 3.0	When surround is folded down to stereo, dialogue can end up quiet against the effects. This is the fix for “I cannot hear what they are saying on my phone”. Try 1.5 to 2.0. We ship 1.0 so that updating never changes how loud anything is for anyone

Worth knowing. Most playback never touches any of this. The server plays a file as it is whenever the device can take it, only swaps the container when that is enough, and re-encodes as a last resort.

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Remote streams

Applies only to people watching from outside your network. Anything on your own network is never capped, never counted, and never touched by these.

Setting	Default	Range	What it does
Maximum resolution	No cap	480p, 720p, 1080p, 2160p	Ceiling for remote viewers. Useful when your upload cannot sustain 4K to three houses
Maximum bitrate	No cap	Up to 100000 kbps	Ceiling on the data rate. Compared against the file’s average bitrate, which is size divided by duration
Trusted proxies	Blank	A list of CIDR ranges	If your server sits behind a reverse proxy, list it here so the real visitor address is read from the forwarded headers instead of the proxy’s own
Extra local subnets	Blank	A list of CIDR ranges	Networks that should count as local for the purpose of streaming

The two caps are independent, which is worth pointing out because most products couple them: you can cap the bitrate without forcing the resolution down, so a 4K stream simply gets less generous rather than becoming 1080p.

When a cap is what is limiting a stream, it is named as the reason in the diagnostics overlay in the player, so you can see why something looks softer than you expected.

Extra local subnets, and what it does not do

If your server is on a VLAN, or in Docker with its own bridge network, or reachable over a VPN, traffic from your own house can arrive looking remote. It then gets capped and counted as remote, which is wrong and is one of the most common complaints in this category.

Listing those ranges here fixes exactly that: they are classified as local for streaming, so they are never capped and never count against your five remote streams.

Careful, and deliberately so. This grants nothing else. Adding a range here does not make anyone on it trusted, does not skip sign-in, and does not give anyone the ability to manage your server. A setting that does all of that exists in other products and it is a foot-gun. Ours does not.

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Library and background work

Setting	Default	Range	What it does
Generate preview thumbnails	On	On, off	The strip of images you see when you scrub the timeline. Turning it off stops making new ones. Existing previews are kept, because they represent hours of work
Preview frame interval	3 s	1 to 30	How often a preview frame is captured. Smaller is smoother scrubbing and more disk. Applies to previews generated from now on; nothing already made is thrown away
Preview frame width	240 px	120 to 480	How big each preview frame is. Same rule: new ones only
Scan at low priority	Off	On, off	Runs the scanner’s file inspection at idle priority. Turn it on if a scan makes the machine unresponsive

Two related settings live in Libraries rather than here, because they are about your library rather than about performance: how often the server rescans, and how many files it inspects at once.

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Live TV and recording

Setting	Default	Range	What it does
Timeshift buffer	120 min	10 to 1440	How far back you can rewind live TV. This is disk, per active channel
Default recording pre-padding	0 min	0 to 10	Start every recording this many minutes early, when you have not chosen a padding yourself
Default recording post-padding	0 min	0 to 120	Run every recording this many minutes late. Set this if you record sport
Guide refresh	6 h	1 to 48	How often guide data is pulled
Playlist refresh	12 h	1 to 168	How often the channel list is pulled
Live stream grace period	45 s	15 to 600	How long a live connection is held open after you stop watching. Longer makes flicking between channels instant; shorter is politer to a provider that counts connections

Padding you choose on an individual recording always wins over the defaults, including when you deliberately choose zero.

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Server and data

Setting	Default	Range	What it does
Database cache	Auto	0 to 1024 MB	Memory the database is allowed for caching. Auto is right for almost everyone. A very large library on a machine with plenty of memory may benefit from more
Nightly backups kept	7	2 to 30	How many nightly snapshots to keep
Weekly backups kept	4	0 to 12	How many weekly snapshots to keep
Keep transcoder logs	Off	On, off	Writes the full encoder log for each session to disk instead of keeping a short tail in memory. Turn it on when you are reporting a playback problem, then turn it off. The newest fifty are kept

Move data directory

Moves your database, artwork, and thumbnails to another drive. Not your media, which is untouched.

Available on Windows installs. It checks the target is empty, writable, not inside the current one, and has room, then stages the move for the next restart. The old folder is copied rather than moved and is left exactly where it was, so you can prove the new location works before anything is thrown away. A separate button removes the old data when you are ready, and tells you how much space that frees.

If the copy fails for any reason, the server boots from the old folder as though nothing happened and tries again next time.

On Linux and Docker, do it by hand: stop the service, move the folder, update the service file or your compose volume, start it again.

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Things that are deliberately not here

Stated so you stop looking for them:

• A file chunk size for direct play. This is not a real server setting. When a device plays a file directly it is asking for byte ranges over HTTP and the device decides how much to ask for. The knob some products are rumoured to have does not exist in them either. The real levers for network behaviour are segment duration and encoder pacing, both above.
• A hard processor percentage cap. Nobody in this category ships one, because the mechanisms for it are per-platform and unpleasant. Threads and priority are the honest levers and they are above.
• A total upload bandwidth budget. Per-stream caps are here; an aggregate ceiling is not, yet.
• Quality by constant rate factor. Our streaming ladder is bitrate-driven by design, so an encoder quality target would not do what you expect.
• Deleting segments mid-session. It saves a little disk and breaks instant seeking backwards.
• Trusting a subnet for authentication. See the note above. Not an oversight.