[x265] [RFC] Add support for tile header generation

[Steve Borho]

On 10/28, Nicolas Morey-Chaisemartin wrote:
> Hi,
> 
> I don't know if this makes sense for the mainstream but we use x265 to
> generate a bitstream with tiles.  This is a patch that simply add the
> capabilities to generate tile compliant headers although there is
> absolutely no support for encoding using tiles.

Tiles are an interesting problem. On the one hand they would allow more
CTUs to be available for encode at the same time; always a boon. But on
the other hand a compliant Main or Main10 encode cannot use tiles and
WPP at the same time.

And unless you restrict the ME search areas to also be tile based
(introducing even more tile boundary artifacts), you also limit the
effectiveness of frame parallelism.

For us, tiles are a losing proposition: less parallelism, less
compression efficiency, less visual quality.

-- 
Steve Borho