# Outputs · NDI · SRT · RTMP · External: SRT

> Contribution over the internet.

Glider documentation · Playout & On Air · Web page: https://cgglider.com/docs/outputs/srt/

Sections of this page: [How outputs work](https://cgglider.com/docs/outputs.md) · [Frame timing & colour](https://cgglider.com/docs/outputs/timing.md) · [Sources, channels & signals](https://cgglider.com/docs/outputs/sources.md) · [NDI](https://cgglider.com/docs/outputs/ndi.md) · [External (SDI) & fullscreen](https://cgglider.com/docs/outputs/external.md) · [SRT](https://cgglider.com/docs/outputs/srt.md) · [RTMP streaming](https://cgglider.com/docs/outputs/rtmp.md) · [API](https://cgglider.com/docs/outputs/api.md)

SRT outputs encode with ffmpeg, which must be built with libsrt. Glider looks for ffmpeg on the PATH and in the usual install folders; Settings › Outputs › Runtimes says whether the one it found can send SRT, and takes a path to another.

| Field | Meaning |
| --- | --- |
| Type | Listener: a decoder connects to this machine's port. Caller: this machine connects to the decoder. |
| Latency | SRT's receive buffer. 120 ms on a LAN; 3–4× the round-trip time across the internet. |
| Passphrase | 10–79 characters turns on AES encryption; both ends need the same one. |
| Bitrate | H.264 constant bitrate. |

Frames reach ffmpeg already converted to 4:2:0 BT.709, a third of the bytes of the raw picture. A frame the encoder cannot take in time is dropped rather than queued, so the stream never drifts behind real time; the Status column counts drops.