Since the release of Dolby Atmos Renderer v3.7, the software now includes the ability to add custom video to the MP4 file exported from the Renderer.

     
A couple of things to note when using custom video files:

• The custom video must be either an MP4 file containing a video elementary stream encoded as H.264 / MPEG-4 AVC or a raw h.264 / MPEG-4 AVC video elementary file (*.h264). MOV, AVI, MXF and other video file formats are not supported.   
• Any audio in the MP4 with custom video will be discarded. 
• The frame rate of the video elementary stream should match the frame rate of the Dolby Atmos Master. Video frame rates higher than 30 fps are not supported.
• For A/V sync the custom video file must match the start point of the Atmos master file or the manually set in point.  While the Dolby Atmos Master file can have manually set in/out points, the custom video cannot. The custom video file cannot contain more pre-roll than the Dolby Atmos Master file.   
• If it is unavoidable to have more pre-roll in the custom video file,  the Dolby Atmos Conversion Tool can be used to add silence to the head of a Dolby Atmos Master file.
• The longer of the two files will determine the duration of the MP4 export.

If MOV or MXF are all that is available these can be transcoded to MP4 with H.264 video by using tools such as Apple Final Cut Compressor, Adobe Media Export, Adobe Premiere, Avid Media Composer, or Blackmagic Designs DaVinci Resolve among others.

You may also want to consider using AWS Elemental MediaConvert or another cloud-based encoding services to transcode the video. The audio source for the MP4 can be the MP4 exported from the Dolby Atmos Renderer that contains Dolby Digital Plus JOC audio, or AWS MediaConvert can natively encode Dolby Digital Plus JOC from either a .atmos file set or ADM BWF.

A good tutorial on using AWS MediaConvert can be found YouTube.

See this article for more information on using the exported MP4 file as source for packaging as streaming media

Can I use an MP4 file from the Renderer to create streaming media?

See this article for more information on various playback scenarios using the MP4 exported from the Renderer  

How do I QC my Atmos mix?