Clean HDMI Out Support in FiLMiC Pro

Technical Overview

When clean HDMI out is enabled in FiLMiC Pro, it will output a clean video feed (no interface elements visible) to an external display via a compatible HDMI adapter. 

An iOS only feature includes the ability to also output audio over HDMI as well.

Please note that clean HDMI out is not an uncompressed feed similar to what you might find on high end cameras, and is governed by the smartphone or tablet’s hardware and associated limitations.

Use Cases - What is Clean HDMI Out good for?

FiLMiC Pro’s Clean HDMI Out is designed for integrating FiLMiC Pro into multi-cam workflows and for live streaming purposes. 

For example: 

  • Use 4 smartphones in combination with the ATEM Mini switcher to create a multicam studio without the need for expensive dedicated video cameras; ideal for live streaming.
  • You can now use FiLMiC Pro as a video source in OBS or Streamlabs OBS when coupled with the Elgato CamLink 4K.

What is Clean HDMI Out unsuitable for?

  • As the HDMI output of all smartphones applies some form of compression/upscaling, there is no benefit in recording to an external recorder. The internal recording to the device will always be superior to that of an external recording.
  • For recording internally while outputting over HDMI above 1080p on iOS (this introduces stutter in the HDMI feed, but does not impact the internal recording).

What Resolution & FPS Is Used for Output?

The resolution and framerate output over HDMI is determined by the device hardware (both phone and HDMI adaptor) and cannot be set by FiLMiC Pro in conjunction with the phones thermal state. On older devices that are under thermal stress, framerate may be reduced to avoid thermal shutdown events.

This means that if you set FiLMiC Pro to 4K but your device only supports a max resolution of 1080 over HDMI out, the clean feed out will be in 1080p.

iPhone

All models of iPhone currently support a maximum output resolution of 1080p (1920x1080) at 59.94fps.

iPad (lightning equipped models)

All models of iPad with a lightning port currently support a maximum output resolution of 1080p (1920x1080) at 59.94fps.

 iPad Pro (USB-C)

The iPad Pro equipped with USB-C port is capable of outputting 4K UHD (3840x2160) at 59.94fps. USB-C equipped iPad Pros can output their stream via the USB-C cable, no HDMI adapter or capture card is necessary.

Android (Samsung)

Samsung devices tested (S10+, Note 10+) output at 4K DCI4096x2160 at 59.94fps.

Behavior with Library

iOS and Android differs in expected behavior when playing a clip in the library with Clean HDMI Out enabled.

iOS is designed so that the HDMI out goes blank when playing a clip back from the library. This is a technical requirement. Clips will need to be consumed on the device (audio and video) and not on the external display connected via HDMI.

On Android, library playback will be mirrored on both the device and the HDMI source, albeit without any audio coming through the HDMI display.

Best Practice Guide

  1. (Android Only): When streaming instead of recording, for the highest quality output over HDMI, set FiLMiC Pro to 4K under Settings > Resolution. Even if your device only supports 1080p as the max output resolution over HDMI (e.g. iPhone), the output will be superior when FiLMiC Pro is set to 4K.
  2. (iOS Only): When recording internally above 1080p on iPhone, stutter will be introduced into the Clean HDMI out feed. This appears to be a limitation of iPhone devices, and will not impact your internal recording. To avoid stutter while recording internally, set FiLMiC Pro to 1080p.