Using NDI|HX Outputs

NDI|HX output support requires a paid license for use beyond 30 minutes. NDI|HX output is currently supported on Windows (NVIDIA NVENC hardware and OpenH264 software) and Linux (OpenH264 software).

Multiview for NDI can produce multiview outputs using the NDI High Bandwidth (SpeedHQ) or H.264/HEVC (NDI|HX) codecs on supported platforms and hardware.

Codecs Supported

SpeedHQ (NDI High Bandwidth)

The default output codec for Multiview for NDI is the SpeedHQ, or NDI High Bandwidth codec.

H.264/H.265 (NDI|HX)

As of the latest published version, the following encoders are supported by Multiview for NDI.

Platform	Codec	Encoder Type	Notes
Windows	H.264 or HEVC	Hardware - NVIDIA NVENC	Requires a compatible NVIDIA card - anything newer than GTX 980 should work fine. Uses API version 12.0.
Windows	H.264	Software - Cisco OpenH264	Included as a reference/test. Slow and requires a lot of resources.
Linux	H.264	Software - Cisco OpenH264	Included as a reference/test. Slow and requires a lot of resources.

Configuring a Multiview Output for NDI|HX Output

Web UI

Set the Encoder Type in the Web UI

1. Select the multiview output you want to edit.

2. Click Edit Layout

3. Scroll to the bottom of the page and you will see a section called Encoder Settings

4. Select the encoder you wish to use.

5. If the encoder selected is an NDI|HX encoder, choose your bitrate.

6. Click Save next to the bitrate field.

The multiview will restart its output using the encoder you have selected.

The OpenH264 encoder uses software (CPU-based) encoding. It is known to be slow and is only included as a demonstration.

HTTP API

Change Encoder using the HTTP API

Using the API, compose a GET request to http://[host]:8901/viewer/{viewerNum}/encoder/{typeCode}/bps/{bitrateBps}.

Encoder Type	TypeCode
NVIDIA - NVENC, H.264	nvench264
NVIDIA - NVENC, HEVC (H.265)	nvenchevc
OpenH264 (H.264)	openh264
SpeedHQ (NDI Full Bandwidth)	speedhq

For example, the following will change the first viewer's encoder to openh264 with a bitrate of 10 megabits per second (10,000,000 bps):

http://localhost:8901/viewer/0/encoder/openh264/bitrate/10000

When choosing the SpeedHQ codec, bitrate can take on any value as it is ignored.

Technical Notes

• H.264 and H.265 encoders from Multiview for NDI will only send intra-frames (i-frames). P-frames and b-frames are not used.

• The OpenH264 encoder from Cisco uses software (CPU) to encode h.264 frames. As it tends to be much slower than hardware, it is not recommended to use the OpenH264 encoder.