ffmpeg for EL7

[Nicolas Chauvet]

2016-08-24 20:19 GMT+02:00 Orion Poplawski <orion at cora.nwra.com>:
> On 08/24/2016 11:35 AM, Nicolas Chauvet wrote:
>> 2016-08-24 18:55 GMT+02:00 Orion Poplawski <orion at cora.nwra.com>:
>>> On 08/23/2016 12:15 PM, Nicolas Chauvet wrote:
>>>> 2016-08-23 20:06 GMT+02:00 Orion Poplawski <orion at cora.nwra.com>:
>>>>> Does anyone here have any ffmpeg knowledge that would give a reason for
>>>>> preferring anything other than the current ffmpeg 3.1.1 for EL7?  Does ffmpeg
>>>>> have a long-term-support branch?
>>>> There is issue with stable vlc-2.2x which I plan to have in el7, also
>>>> the current kodi 0.16 version doesn't cope well with ffmpeg 3.1x
>>>> I think it's easier to have ffmpeg 3.0x in el7, but then I don't know
>>>> other dependencies that might have issue.
>>>
>>> Given the pain of later updates, it might be worth waiting a bit for vlc 3.0
>>> and kodi 0.17 to land (or get sufficiently stable).
>>
>> I don't expect vlc-3 in EL7 as a first step. VLC 2.2x is there and
>> more relevant for long term support, and specially since EL8 shoudn't
>> be that far away for vlc-3x.
>
> Okay, although based on past timescales I wouldn't expect EL8 until Q4 2017.
yep, will have a strong stable vlc-3 by then ;)

>> Based on that ffmpeg-2.8x seems a more relevant ABI to start with EL7.
>> And later we can still update the whole multimedia stack with
>> ffmpeg-3.1+ vlc3+ koji17 then introduce a fmpeg-2.8x as ffmpeg-compat
>> to keep "stable ABI"
>>
>> This has always been a problem to build latest ffmpeg in stable
>> release without to break ABI. we should probably have a "SCL build of
>> ffmpeg" for those that will only rely on the ffmpeg binaries or fast
>> moving projects using the ffmpeg libraries.
>
> One suggestion that's been getting more traction on the EPEL side of things is
> to just start with versioned packages that can co-exist.  So start with
> ffmpeg2.8 and ffmpeg3.0 from the start.

I don't quite understand the proposition related to ffmpeg. Using
version in name doesn't seem to say which one should be chosen by
default for link.
Specially as ffmpeg doesn't do symbol version, if one process has
dependencies using both version, it will crash.
Also ffmpeg as a 3month release cycle, does it mean a new review each time ?

Using ffmpeg/ffmpeg-compat or ffmpeg-compat28 means to use ffmpeg by
default then ffmpeg-compat28 (with only libs) for the few projects
that needs it.

Now I'm more in favour of using ffmpeg 2.8x as a sane default here,
because it should works for all. it share the same ABI as ffmpeg-2.4x
(which is the one from f21 as we are supposed to branch from f20/f21)
Instead there is anachronism in choosing ffmpeg31/0. as the rule of
the game for EL is not to pick the last versions.



-- 
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Nicolas (kwizart)