Relay Player
A modern desktop viewer for UDP, RTP and HLS multicast and unicast streams — with the channel management, network discovery, subtitle handling and live diagnostics that IPTV and AV engineers actually reach for, not just a bare video window.
Built for great IP streaming video playback — for those who need it.
Relay Player was written by AV/IPTV engineers who were tired of clunky legacy tools — every feature here comes from a real deployment, not a spec sheet.
UDP, RTP, HLS & more
Multicast and unicast UDP, RTP, HLS and any other URL the media engine accepts — including RTSP — all sitting in the same channel list.
Live-preview channel editor
Number, name, type, address and logo, with a live URL preview. Paste a full udp:// address straight in — Relay Player cleans it up and shows what changed.
Search, sort & reorder
Ctrl+F to filter by name, number, address or URL. Sort any column. Drag handles or Alt+Up/Down to reorder — export always keeps the authored order.
M3U / M3U8 import
Handles tvg-chno, group-title, #EXTGRP and bare URLs with no #EXTINF at all. Previews what it found — and can split it straight into one list per group — before anything is added.
SAP discovery
Listens for sessions announced on the network and lists them automatically, with a status readout that separates "nothing announcing" from "arriving but not parsing".
Subtitles & captions
Teletext and DVB bitmap subtitles, both handled without a region setting. Diagnostics reports whether the decoder is even present.
Lossless recording
MPEG-TS by default, plus MP4, MOV and Program Stream. The stream is copied to disk exactly as it arrives — nothing is re-encoded.
Built-in diagnostics
Three live graphs, transport health counters, host stats and raw engine counters — with one-click copy or save for a support ticket.
Multicast interface selection
Pick the network adapter that actually carries your streams, instead of leaving it to Windows' routing table.
A channel catalogue you don't have to build yourself.
Global TV is an optional catalogue of several thousand public internet channels, compiled by a separate open-source project. It's shown in the channel selector by default but stays empty — and Relay Player still makes no network request of its own — until you choose to download it.
- Opt-in only. Nothing is fetched until you ask.
- Cached, refreshable and removable. Update it when you want new channels, or remove it entirely.
- Star what you keep watching. The catalogue itself is read-only, but any channel in it can be starred straight into Favourites — an ordinary, editable list.
- Searchable. The same Ctrl+F search finds a channel by name, number or address across the whole catalogue.
Looking for a source to point Global TV at, or a playlist of your own? See finding more channels.
Teletext and DVB, without a region setting.
A toggle plus a track picker. Teletext — as used by Australian and UK broadcasters — and DVB bitmap subtitles, used most other places, are both handled the same way, no region setting required.
- Keeps checking. A teletext page only transmits while there's dialogue, so discovery polls for up to thirty seconds rather than giving up instantly.
- Configurable. Automatic enabling, a preferred language, and a teletext page override for a stream that declares the wrong one.
- Diagnosable. The diagnostics window shows whether each decoder is even present — "no captions on this stream" versus "the decoder is missing".
See what the stream is actually doing.
Three live graphs — bitrate, process memory and CPU — alongside transport health counters, host resource use and the engine's own raw counters. The screenshot above is a real capture with a handful of discontinuities and lost pictures showing, which is exactly the kind of thing this window exists to surface.
- Transport health at a glance. Corrupted blocks, discontinuities, lost pictures and lost audio buffers, flagged the moment they're non-zero.
- Built for a support ticket. Copy report or Save report puts the full picture in the clipboard or on disk.
There's more once you start digging.
The rest of what's in the free build — smaller details that add up on a long shift.
- No network access of its own. No update check, telemetry, licence check or analytics — the only outbound requests are the ones you explicitly ask for: the Global TV catalogue, and playlist logos.
- Radio & audio-only mode. A stream with no video shows the channel's own artwork instead of a black rectangle.
- Deinterlacing. Auto, always-on or off, with nine filters to choose from — reachable from Settings or a right-click on the video.
- Picture settle delay. Holds the picture back briefly on tune so you never see the grey blocks of a decoder filling in frames it never received.
- Tile grid view. A logo-tile view of the channel list at three sizes, alongside the standard detail list.
- Local file playback. Open recordings or other video and audio files with a full transport bar — play, pause, seek, elapsed and total time.
- Recording destinations. Local or a network share, verified by actually writing to it — plus a disk-space estimate before you start.
- Startup & kiosk options. Tune a chosen channel, launch straight into fullscreen, and turn captions on automatically — enough for an unattended display with nobody there to click anything.
- Atomic, quarantined data. Channels and settings are kept in separate files, written atomically, and quarantined rather than lost if one fails to parse.
Fast to drive without the mouse.
Every shortcut works from the main window; fullscreen adds a couple of its own.
| Key | Action |
|---|---|
| Enter | Play the selected channel |
| Ctrl+F | Focus the search box |
| Ctrl+A | Cycle to the next audio track |
| Escape | Clear the search, or leave fullscreen |
| F11 | Toggle fullscreen |
| Page Up / Page Down | Previous / next channel |
| Space | Re-show the channel banner in fullscreen |
| Alt+Up / Alt+Down | Move the selected channel |
System requirements.
Nothing unusual — a modern 64-bit Windows machine is all it takes.
| Operating system | Windows 10 or 11, 64-bit. Not supported on 32-bit Windows or Windows 7/8. |
|---|---|
| Runtime | None to install separately — the .NET 8 runtime is bundled with the application. |
| Disk space | 500 MB available. |
| Memory | 4 GB RAM minimum, 8 GB recommended. |
| Network | A path capable of delivering the stream being played. UDP multicast requires IGMP support on the network in between. No internet access is required to run Relay Player. |
Get Relay Player.
Free to download and use. No account, licence key or licence server required.
This build isn't code-signed yet, so Windows may show an "unrecognised app" warning on first run. Click More info, then Run anyway. Full details, checksums and release notes are on the downloads page.