🎞️ Playout

Playout

Broadcast playout automation — file playback, live inputs, CG graphics overlay, scheduling and multi-format outputs. Each channel runs its own independent encoder.

Signal Flow

Each channel has a dedicated FFmpeg encoder (NVENC GPU encode). The TEE muxer feeds all outputs simultaneously — UDP/SRT/RTMP outputs, HLS preview and the WebRTC program monitor share one encode.

Channels

Multiple independent channels, each with its own playlist, encoder and outputs

Output resolution, frame rate and audio format per channel

Multiple simultaneous outputs (UDP, SRT, RTMP) via TEE — one encode, many destinations

Transport bar: PLAY / STOP / PAUSE / NEXT, item and total timers

CG and ON-AIR indicators visible on every tab

Playlist

Drag & drop editor — drop or move inserts above the focused row

Item types: media files from the library and live inputs (HLS/UDP/SRT)

Per-item trim: start offset + duration — following start times recalculate automatically

Loop mode for continuous 24/7 playback

Computed start/end times for every item; temp editor for batch changes

Trimmed items

A yellow duration cell marks an item that plays shorter than its full file length. The tooltip shows the original duration and start offset. Scissors icon opens the trim editor.

Media Library

File browser with folders, multi-select and delete

Upload via dialog or drag & drop — progress modal with per-file status

Uploads can be minimized to a floating widget and keep running in the background while you work

Files are normalized to the house format (uniform timescale, color space) for glitch-free playback

Eye icon previews a file before adding it to the playlist

Live Inputs

HLS, UDP and SRT sources as reusable live input definitions

A live input is a playlist item like any other — switch between files and live

Fixed duration or manual NEXT to leave a live segment

Elements

Text, logo, ticker/crawl, clock, lower thirds, video overlay, weather

CG templates are per-channel; each element has its own properties (position, size, animation, timing)

Master CG switch + per-element toggles; preview reflects the on-air state

CG Profiles

Named profiles override element properties per profile — e.g. a clean feed and a branded feed

Switching the on-air profile re-renders the overlay

Secondary events in the schedule can activate a CG profile or item automatically

Live CG (no restart)

With live CG enabled in channel config, toggling CG switches the overlay instantly inside the running encoder — no output interruption. Without it, CG changes restart the encoder (short glitch).

Audio

Stereo LED level meters (L/R) live from the program output

Master volume — drag on the meter card

AUTO loudness normalization (EBU R128) per channel

Scheduler

Opt-in per channel (enable in Settings); manual transport keeps working

Rules: daily, weekly (per weekday) or one-time date

Channel time zone aware, handles playlists crossing midnight

Priority resolves overlapping rules

Autostart option launches the scheduled playlist after a server restart

Program Monitor

Low-latency WebRTC (WHEP) program monitor directly in the browser

Sticky preview row stays visible at the top while editing

EPG

Block EPG — programme titles generated from the playlist

EPG dialog closes only via X / OK / Cancel (no accidental close)

SRT output:

Address format

e.g.

Client reads via

Limits & notes

GPU is used for encoding only; decode/filters run on CPU

Heterogeneous sources are normalized on upload — do not bypass the media library for playlist files

Without live CG, every CG change restarts the encoder (short output glitch)

CG Overlay

Channels

Outputs

Playlists

Signal Flow

Broadcast playout automation with file playback, live switching, CG overlay, and scheduling. Access via /playout.

Signal Flow

Channels

Multiple independent channels

Output resolution & audio format per channel

Multiple simultaneous outputs (UDP, SRT, RTMP)

Master volume control

Playlists

Drag & drop playlist editor

Loop mode (continuous)

File items (video/audio from media library)

Live input items (HLS/UDP/SRT sources)

Schedule-based auto-switching

CG Overlay

HTML/CSS-based CG templates

Logo overlay, lower thirds, tickers

Chromium-based rendering

Real-time preview

Per-element show/hide control

Outputs

UDP multicast (IPTV network)

SRT (remote mediamtx / contribution)

RTMP (YouTube, Twitch, etc.)

HLS (web player)

Multiple outputs simultaneously

SRT Output:

Automation & Live Graphics

Audio Metering & Loudness

Stereo L/R LED level meters next to the program preview show the live output level. Drag the meter vertically to set the on-air master volume (drives the streamer level).

The AUTO checkbox enables EBU R128 auto loudness (loudnorm) on the output — it normalizes the level automatically instead of the manual gain.

Automation: Scheduler

Enable per channel in Settings → Automation (opt-in). The scheduler switches the channel's playlist by time (daily / weekly / one-off), evaluated in the channel timezone; the highest priority wins. Auto-start can start a stopped channel when a schedule begins.

Add schedules in Settings → Schedule (playlist, recurrence, day/date, start–end time, priority).

Live CG (instant toggle)

Enable in Settings → Graphics. With Live CG on, the CG overlay turns on/off instantly via ZeroMQ without restarting the encoder (no seam). It uses the cg.pipe renderer (text/logo/ticker). Restart playback after changing the option.

This is also the real fix for stale CG lingering in the preview after turning CG off.

Transport Bar & Preview

Transport controls (Play/Stop/Pause/Next, CG and ON-AIR toggles, timers) live in the tab strip; the active button is highlighted and the total-elapsed timer turns light blue while playing.

The preview row is frozen at the top while the lists below scroll.

Secondary Events & SCTE-35 Ad Breaks

Each playlist item can carry secondary events — graphics or ad cues fired at an offset within that item. Open them from the purple clapper icon next to the EPG eye. Types: CG show/hide (needs live-CG mode) and SCTE-35 ad out/in. A duration auto-pairs the matching hide/return.

Fire an ad break live from the transport bar: the SCTE AD presets (15/30/60/120s) or a custom length emit a SCTE-35 CUE-OUT into the HLS output immediately; a red countdown badge shows the remaining time and RETURN ends it early (CUE-IN).

The Item / Remaining / Elapsed timers sit in the top breadcrumb bar: Item is green, Elapsed is dark blue, Remaining flashes red under 10 seconds.