Video Bitrate Parameters

Changing the bitrate of the outgoing and incoming video and for rooms

They are separated in two groups: source side (push) options for the sender of the video and viewer side (view) options for the viewer of the video. Some of them are especially for rooms.

Viewer-side &videobitrate overrides the sender default from &outboundvideobitrate, while &maxvideobitrate remains a software-enforced cap. Room-level limits still apply where relevant.

Depending on browser/negotiation, &videobitrate and &outboundvideobitrate can also be enforced via SDP munging and may act as caps.

For room guest-to-guest quality, the main setting is &totalroombitrate / &trb. If the main director is connected, the director's current room bitrate is sent to guests. If no main director is controlling the room bitrate, each guest uses their own URL value or the default room behavior.

Source side options

You have to add them to the source side (&push).

Parameter	Explanation
&outboundvideobitrate	Default target video bitrate for outgoing streams
&maxvideobitrate	Hard max video bitrate out for this publisher, per stream
&limittotalbitrate	Limits the total outbound bitrate
&roombitrate	Caps how much other guests can request from this publisher inside a group room
&maxbandwidth	Judges the available bandwidth of a sender's connection

Viewer side options

You have to add them to the viewer side (&room or &view or &scene or &solo).

Parameter	Explanation
&videobitrate	Sets the desired per-stream bitrate in kbps; in rooms it can initialize the total room bitrate only when no &trb is set
&totalscenebitrate	Total bitrate budget a scene/view link uses across visible video feeds
&totalroombitrate	Total guest-to-guest room viewing budget; alias &trb
&totalbitrate	Shortcut that sets both scene and room total bitrate flags; use &trb or &tsb when you want one specific target
&controlroombitrate	Lets a guest lower their own room receive budget from the settings panel
&zoomedbitrate	Lets you set the target bitrate for a guest when they 'zoom in' (fullscreen) on a video
&optimize	Video bitrate reduced when the video is not visible in OBS (not active in a scene)
&screensharebitrate	Lets you manually set the video bitrate for screen-shares

Room-only and mobile room options

These parameters are for guest room calls where mobile device safety and mesh-network load matter.

Parameter	Explanation
&roomtier1bitrate	Automatic room-only total bitrate tier for weaker mobile devices
&rt1b	Short alias for &roomtier1bitrate
&roomonlylowbitrate	Alias for &roomtier1bitrate
&rolb	Short alias for &roomtier1bitrate
&roomtier2bitrate	Automatic room-only total bitrate tier for normal or stronger devices
&rt2b	Short alias for &roomtier2bitrate
&roomonlybitrate	Alias for &roomtier2bitrate
&rob	Short alias for &roomtier2bitrate
&maxmobilebitrate	Normal mobile sender cap for guest room publishing
&lowmobilebitrate	Lower fallback mobile sender cap for older or overloaded mobile devices
&nomobilebitratecap	Disables only the mobile sender bitrate safety cap

Automatic room-only tiers are meant for guest-only conferencing rooms. If a director or scene viewer is connected, use explicit room or scene bitrate parameters instead.

Related

Room-only mobile bitrate tiersVideo ParametersVideo bitrate in roomsVideo bitrate for push/view links