A few ffmpeg queries

[Mark Carroll]

On 10 Sep 2017, Vangelis forthnet wrote:
(snip)
>  If you (or anybody else for that matter)
> has a non-released version of FFmpeg
> which is quite recent and you know it
> works OK with DASH/HVF remuxing,
> you can make that warning go away via
> "--ffmpeg-force" switch
> (Bypass version checks and assume ffmpeg is version 3.0 or higher).

Excellent, thank you, I can easily just add that to my shell aliases.

(snip)
>  There has been a related PR submitted
> earlier in May,
>
> https://github.com/get-iplayer/get_iplayer/pull/330
>
> I think I have to completely align myself with
> the maintainer's comment...
(snip)

Unfortunately,

>  I, too, could not find on
> https://github.com/FFmpeg/FFmpeg
> a commit with given HASH (523da8eac1);
> but it does crop up in a Google search as an
> OpenBSD version... maybe said commit
> references some OpenBSD specific patch (?)

... rather than being some nightly build that I happened to individually
choose, it is from the package one gets from OpenBSD's standard amd64
binary package repository for the current stable release; that gets
updated only a couple of times per year. (I could have asked on that
pull request if that's sufficient exception but further comments are
closed down.) My initial hope was that we could also identify ffmpeg
version not by the hashes but simply by the "75412" if it were some
monotonically increasing commit number relating to the upstream git
repository, then rather than check for specific hashes we could use
simple integer range tests.

As it now turns out, I've no idea why OpenBSD chose that commit nor if
they patch ffmpeg; I don't have a local checkout of their source tree
and I do not quickly see a way to browse it via the web. But they use
CVS (!) and I have no idea how it all interacts with that I guess they
must fetch from git to populate it. So it may be that the "75412"
relates to OpenBSD's CVS tree rather than something more widely
applicable like upstream's git commit history and I would gladly not
clutter get-iplayer with detail that is OpenBSD-specific.

-- Mark