Input settings

How to setup your Flexbox to best match your video

November 12, 2025

ClearView Flex supports the following input types:

• SDI (default)
• HDMI
• NDI

SDI and HDMI are both dedicated physical connections to provide Audio/Video that plug directly into the Flexbox through their respective ports, whilst NDI operates over the existing network ethernet cable used to provide internet connectivity.

NDI

You can receive an NDI feed from Avid.

NDI is currently supported with NDI 4+.

NDI is disabled by default for Flexboxes and has to be enabled in CVF Admin Flexbox settings first. This is to prevent unnecessary network probing to identify NDI sources.

When you select NDI, you can then select an NDI source to use. The sources you can see are determined by the NDI groups, discovery and remote servers configured in your NDI settings. By default, we will select the first available source if one is available.

Note that, due to a limitation with NDI, we are unable to provide 8-bit 4:4:4 input.

Troubleshooting

If your NDI source becomes unavailable (ie. it is disconnected or taken offline) then you will need to select a new source or reconnect the original source to continue streaming.

If you receive a message saying that “No NDI Sources are available”, then you will need to check your NDI source is online or connect using SDI or HDMI.

Capture Format

To properly support 8-bit and 10-bit colour bit-depths in both RGB and YUV, you will need to specify the format of the video input.

You can select the following options:

• 8-bit 4:2:2 YUV
• 8-bit 4:4:4 RGB
• 10-bit 4:2:2 YUV (default)
• 10-bit 4:4:4 RGB

Please note:

• The capture format should match the input format of the video source connected to the Flexbox. It is not directly related to the output format of the Flexbox.
• Selecting an 8-bit capture format disables the 10-bit output bit-depth option.
• 8-bit 4:4:4 RGB, 10-bit 4:2:2 YUV, 10-bit 4:4:4 RGB are not yet supported with the NDI input.

Dynamic Range

You can select the following options:

• SDR (default)
• HDR

HDR Metadata

Once you select HDR in the Presenter view, ClearView Flex will begin looking for HDR metadata in the SDI/HDMI input (such as the display primaries, white point, min/max mastering luminance and maxCLL/maxFALL). This metadata will be passed through to the HDR capable viewers.

If no embedded metadata is found, we will fall back to industry standard HDR10 at 1000 nits using the Rec. 2020 color primaries with ST2084 PQ transfer curve. Please note that consumer displays differ and will have different capabilities of sustained and peak brightness.

If you are natively working in the P3 colorspace, this should be wrapped in a Rec. 2020 container for remote viewing on consumer devices. There is a switch available in the iPhone/iPad app to select P3 primaries and D65 white point, allowing for the most accurate review of theatrical or Dolby Vision work in progress. As there is no way to signal P3-D65 to TVs they should be specifically calibrated to P3-D65.

Audio Channels

You can also select the audio channels of the input:

• Stereo (default)
• 5.1

Please note:

• Audio bitrates will automatically increase when selecting 5.1.

• If you select 5.1, we will send 5.1 to the Apple TV 4K and downmix for all other devices.

• To downmix from 5.1 surround sound to stereo, we use the matrix recommended in RFC 7845 (which defines Ogg encapsulation for the Opus codec, and is also what the WebRTC ‘multiopus’ implementation is based on). This matrix appears to yield better results than the LtRt or LoRo matrices defined in the ATSC standard for digital audio compression, mainly because it does not discard the LFE channel and has less impact on the dynamic range of the audio signal.