[FFmpeg-devel] [PATCH 1/4] swr: convert resample_common/linear_int16_mmx2/sse2 to yasm.

Andreas Cadhalpun andreas.cadhalpun at googlemail.com
Sat Jul 12 22:20:30 CEST 2014


On 12.07.2014 22:01, Hendrik Leppkes wrote:
> On Sat, Jul 12, 2014 at 9:56 PM, Andreas Cadhalpun
> <andreas.cadhalpun at googlemail.com> wrote:
>> On 12.07.2014 21:40, Hendrik Leppkes wrote:
>>>
>>> On Sat, Jul 12, 2014 at 9:26 PM, Andreas Cadhalpun
>>> <andreas.cadhalpun at googlemail.com> wrote:
>>>
>>>>
>>>> I'm not sure what you mean with 'officially' here. Every symbol exported
>>>> by
>>>> a shared library can be used by another program.
>>>> Even if only other av* libraries use the avpriv_* symbols they can't just
>>>> be
>>>> removed, because that would break ABI compatibility between the old
>>>> version
>>>> of the library using such a symbol with the new version of the other
>>>> library
>>>> not exporting this symbol anymore.
>>>>
>>>
>>> Unrelated to any ABI or API problems, a use-case of mixing different
>>> versions  of the libraries strongly advised against ever using or a
>>> distribution enabling such use, because its hardly ever tested, and
>>> results may be rather unpredictable, especially with a lot of
>>> applications sadly still using some of the API "incorrectly".
>>
>>
>> There shouldn't be any problem, as long as libraries with the same major
>> SOVERSION are ABI backward-compatible.
>> If there would be a problem, I would call it a (very strange) bug.
>> Have you ever heard of such a problem?
>>
>> If you don't want different versions of the libraries used together, you
>> should either bundle all these libraries into a big one or bump all major
>> SOVERSIONs in every release. Neither of those make much sense, I think.
>>
>>
>
> There have been a lot of those bugs, which get fixed when found, but
> its something that easily breaks and is hard to find, so its just
> something you should avoid instead of encourage.

I don't intend to encourage such use, but I can't really prevent it 
either. So I'm trying to make sure it doesn't break in obvious ways.

Best regards,
Andreas




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