[x264-devel] partial support of features in profile

[fx]

On 11/3/2012 3:58 AM, Ran Shalit wrote:
> Hello,
>
> I would like to ask, if x264 support only part of features that the
> standard list for each profile, for example, if there is no FMO
> support in Baseline profile, does it mean that this profile is not
> well supported as should be according to standard and we can't use it
> with any encoder ?
>
> Thank you,
> Ran
>
Your understanding of profiles is backward. Decoders are the only ones that have to support all
of the required parts of whatever profile they claim to support; encoders targeting a profile
merely have to not exceed that. As x264 is not and never will be a decoder, total coverage of
profiles isn't important except as bullet points in a marketing brochure, particularly since
some of them don't help in realistic usage scenarios at all. An encoder can perfectly legally
signal High profile while using nothing but the basic Constrained Baseline tools (and way back
in the day, that's exactly what x264 did if you didn't enable anything else).