[FFmpeg-devel] [PATCH 2/2] Require compilers to support C17.

[Kevin Wheatley]

On Fri, Feb 9, 2024 at 11:22 AM Dominik 'Rathann' Mierzejewski
<dominik at greysector.net> wrote:
> Even so, a C17-supporting compiler (gcc 11.2.1) is available for CentOS 7
> in the devtoolset-11-gcc package (from
> http://mirror.centos.org/centos/7/sclo/x86_64/rh/).

As a 'User' of the FFmpeg project, we have a lot of CentOS/RHEL 7/etc
based headless machines which run FFmpeg and thus we compile versions
of FFmpeg on this platform. This is currently quite common across the
VFX industry as most of the industry is still in the process of moving
away from this to something more recent see https://vfxplatform.com/.

The availability of  "newer" compilers via the devtool set should make
 this proposed requirement a relatively small obstacle for building
newer versions. As such I think that communicating the proposed change
and its implications in the next release versions and the FFmpeg
website should be sufficient, if similar notes for other common
platforms could be added to the release notes/changelog then at least
for users of these Fedora/RHEL derivatives should be fine.

I'm assuming anybody able to compile a custom FFmpeg build, is also
able to arrange to install a prebuilt compiler, so as long as the
dependency doesn't bleed through to a runtime one, all should be good.

On the topic of why users may be so far behind the "current" for the
OS is down to several factors, in VFX  and animation it is not
uncommon to work upon a project for many years prior to releasing,
this means we tend to lock down software versions in use for long
periods of time (switching out compilers, libraries etc can all change
the results of computation and thus our images). Running multiple
projects at once can make changing the OS a long duration process.

We've recently seen a similar issue with vscode bumping glibc
dependencies https://github.com/microsoft/vscode/issues/203375 though
switching glibc versions is a lot more awkward than a compiler
requirement.

Kevin