Syphon, Spout and NDI

Table of Contents

• NDI
  • Capture
    • Audio
  • Display
• Spout
  • Server
• Syphon
  • Server
  • Client

NDI

Note: Due to licensing restrictions you need to compile NDI support by yourself. After that you may use NDI receiver/capturer and sender/display.

Capture

Basic usage is simply:

uv -t ndi -c <compression> [-s embedded --audio-codec <ac>] <receiver>

The above command picks first source found on a local network and sends the data to the receiver.

You may also specify name and/or URL (either in form ip_addr or ip_addr:port, exact URL format may change with future NDI releases) to capture from, eg.:

uv -t "ndi:name=HD10 (DeckLink 4K Extreme)" -c JPEG ultragrid-receiver.example.net
uv -t ndi:url=192.0.2.15 -c JPEG ultragrid-receiver.example.net
uv -t ndi:url=192.0.2.15:5961 -c JPEG ultragrid-receiver.example.net

(Note that the apostrophes in the first command are because the resource name contains spaces.)

You can also let UltraGrid discover available sources on a local network:

uv -t ndi:help

(The list doesn't need to be complete - UltraGrid waits only limited amount of time to response.)

Audio

NDI video capture is capable of capturing video alongside with audio as usual:

uv -t ndi -s embedded -c libavcodec --audio-codec OPUS ultragrid-receiver.example.net

If the NDI source is audio only, it is possible to capture the audio with the NDI vidcap module even in the absence of video signal:

uv -t ndi:name=mic -s embedded --audio-codec OPUS ultragrid-receiver.example.net   # if "mic" is audio only NDI source, no video is sent

Display

Basic usage is quite usual:

uv -d ndi[:name=<n>] [-r embedded] <sender>

Analogically to the capture, the NDI display can also playback the audio without a video.

Spout

Currently there is only Spout server support.

Server

Use following command to create Spout sender:

uv -d gl:spout

Similarly to Syphon, you can specify server name:

uv -d gl:spout=<name>

Syphon

Server

Syphon support is added to UltraGrid OpenGL display. You can run it with following command:

uv -d gl:syphon

Alternatively, you can specify server name (instead of default UltraGrid):

uv -d gl:syphon=<another_name>

Client

Syphon clinet can be simply run as a normal capturer:

uv -t syphon -c <compression> <receiver_addr>