[FFmpeg-devel] MV-HEVC support for decoding of Apple's stereo video

[Anton Khirnov]

Quoting Danny Hong (2024-08-15 21:26:57)
> Quoting Anton Khirnov  (2024-08-15 19:36:47)
> > Yes, it should be submitted to ML within a few months.
> 
> Thank you for the info!  This is great!  We have experience with HEVC
> implementation and also with the layered use case.  If there is anything we
> can help out with the development please let us know or let us know whom to
> reach out to.

Thank you for the offer, but I don't think I will need it, as
* the bulk of the work has been done
* what remains is a long tail of small issues that are more about
  integrating this into our APIs rather than actual multilayer decoding

> One use case is to decode MV-HEVC stereo video into side-by-side (or
> top-to-bottom) format as there are many existing video processing pipelines
> that expect both decoded views packed into a single frame.  Would this
> support be considered?

The way this will work is that different views will be output by decoder
as separate frames with side data indicating their view ID. It is then
trivial to stack them vertically or horizontally using a filter.

Decoding directly into a stacked layout is in general not possible
because of cropping. In cases where you control the input and can be
sure there is no cropping along the relevant dimension, this could
probably be implementable in principle with a custom get_buffer()
callback, but I have not thought about it much.

-- 
Anton Khirnov