[FFmpeg-devel] [PATCHv2 1/2] avdevice/decklink_dec: add support for decoding teletext from 10bit ancillary data

[Marton Balint]

On Wed, 19 Jul 2017, John Warburton wrote:

> On Tue, Jul 18, 2017 at 6:10 PM, Marton Balint <cus at passwd.hu> wrote:
>> On Sat, 8 Jul 2017, Marton Balint wrote:
>>
>>> This also add supports for 4K DeckLink cards because they always output the
>>> ancillary data in 10-bit.
>>>
>>> v2:
>>> - only try teletext decoding for 576i PAL mode
>>> - some comments as requested by Aaron Levinson
>>>
>>> Signed-off-by: Marton Balint <cus at passwd.hu>
>>
>> Applied the series, thanks for all the comments.
>
> Since this patch was applied, the mingw-w64 compiler, gcc version
> 6.4.1, fails to link shared library avdevice-57.dll, giving the
> following error. It is as if the const uint8_t ff_reverse[256] that is
> found in libavutil/reverse.c somehow isn't being discovered by the
> linker. I'm afraid my knowledge beyond this point is zero.
>
> libavdevice/decklink_dec.o:decklink_dec.cpp:(.rdata$.refptr.ff_reverse[.refptr.ff_reverse]+0x0):
> undefined reference to `ff_reverse'
> collect2: error: ld returned 1 exit status
> ffbuild/library.mak:101: recipe for target 'libavdevice/avdevice-57.dll' failed
> make: *** [libavdevice/avdevice-57.dll] Error 1
> Build failure. Please see error messages above.

Hmmm. Does adding ff_reverse to the exported symbols in 
libavutil/libavutil.v fix the problem? Or maybe simply renaming 
every instance of ff_reverse in the codebase to avpriv_reverse?

Thanks,
Marton