Feature: Add support for the Resolume DXV video format

[KevinHughes]

As ffmpeg has had DXV support for quite a while, I thought I'd ask to add support for the DXV codec, which is stored in .mov containers (and thus also uses the .mov filename suffix). DXV is heavily used in the live events industry by VJs so that live video playback, manipulation, and compositing occur as fast as possible on GPUs. While making a show creatives often have to deal with hundreds (if not thousands) of DXV clips, none of which have Finder thumbnails or can be previewed with QuickLook, making file management a complete pain. Providing this capability would be greatly appreciated!

[Marginal]

Looks very do-able. But can you point me to some publicly available sample files, ideally both DXV1 and DXV3?

[KevinHughes]

Hm finding public DXV files is harder than I thought... I've made a directory of a few DXV3 videos - they include videos with and without alpha, at normal and high quality:
https://drive.google.com/drive/folders/1oubSmjCKKnvrSMBMQxamBZpyyHmdgQCO?usp=sharing

[Marginal]

Will be supported in the next release. In the meantime please post if you can find any other publicly available DXV videos - particularly any with transparency.

[KevinHughes]

Thank you so much! I used to use Perian back in the day and greatly appreciate all the effort you've put into this. I've put two DXV3 videos with transparency here, labelled "Transparent DXV3 HQ.mov" and "Transparent DXV3 Normal.mov":

https://drive.google.com/drive/folders/1oubSmjCKKnvrSMBMQxamBZpyyHmdgQCO?usp=sharing

There are some issues with the ffmpeg DXV3 decoder though:

• Transparent video at any quality may appear splotchy in areas that are not 100% transparent. The original ProRes 4444 video and the "official" DXV players/renderers show no artifacts.
• Feeding ffmpeg DXV3 video with dimensions that are not multiples of 16 can cause the video to be skewed or render in odd ways.