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

[Hendrik Leppkes]

On Sat, Jul 12, 2014 at 4:45 PM, Andreas Cadhalpun
<andreas.cadhalpun at googlemail.com> wrote:
> On 12.07.2014 15:40, Ronald S. Bultje wrote:
>>
>> Hi,
>>
>> On Sat, Jul 12, 2014 at 9:35 AM, Andreas Cadhalpun <
>> andreas.cadhalpun at googlemail.com> wrote:
>>
>>> Hi,
>>>
>>> I'm a bit puzzled by this commit.
>>>
>>>
>>> On 30.06.2014 01:19, James Almer wrote:
>>>
>>>> From: Ronald S. Bultje <rsbultje at gmail.com>
>>>>
>>>> ---
>>>>    libswresample/resample_template.c    |  23 +---
>>>>    libswresample/x86/resample.asm       | 225
>>>> ++++++++++++++++++++++++++---------
>>>>    libswresample/x86/resample_mmx.h     | 110 -----------------
>>>>    libswresample/x86/resample_x86_dsp.c |  44 +++----
>>>>    4 files changed, 187 insertions(+), 215 deletions(-)
>>>>
>>> [...]
>>>
>>>   diff --git a/libswresample/x86/resample_mmx.h
>>>>
>>>> b/libswresample/x86/resample_mmx.h
>>>> index 94237b0..b0ea496 100644
>>>> --- a/libswresample/x86/resample_mmx.h
>>>> +++ b/libswresample/x86/resample_mmx.h
>>>> @@ -22,116 +22,6 @@
>>>>    #include "libavutil/cpu.h"
>>>>    #include "libswresample/swresample_internal.h"
>>>>
>>>> -DECLARE_ALIGNED(16, const uint64_t, ff_resample_int16_rounder)[2]    =
>>>> {
>>>> 0x0000000000004000ULL, 0x0000000000000000ULL};
>>>>
>>>
>>> This removes the symbol ff_resample_int16_rounder from libswresample,
>>> which is a backwards incompatible ABI change.
>>>
>>> So can someone explain to me, why this hasn't been accompanied by a major
>>> SOVERSION bump of libswresample?
>>
>>
>>
>> All ff_* symbols are internal.
>
>
> Then shouldn't all of them be declared with something like '__attribute__
> ((visibility ("hidden")))'?
>

This is usually handled by a visibility file (.v), but for some reason
the swresample file doesn't hide ff_* symbols, but that doesn't really
change the fact that ff_* (and avpriv_*) are not part of the public
API/ABI and as such any changes or removals do not require a SONAME
bump.

For the reason why they are not hidden, maybe Michael can comment.

- Hendrik