Compilation error with newer ffmpeg version

[ismangil]

Newer ffmpeg version changed variable names, resulting in build error:

In file included from ../src/pjmedia/ffmpeg_util.c:26:
../src/pjmedia/ffmpeg_util.h:50:12: warning: declaration of 'enum CodecID' will

not be visible outside of this function [-Wvisibility]

enum CodecID *codec_id);

../src/pjmedia/ffmpeg_util.h:52:47: warning: declaration of 'enum CodecID' will

not be visible outside of this function [-Wvisibility]

pj_status_t CodecID_to_pjmedia_format_id(enum CodecID codec_id,

../src/pjmedia/ffmpeg_util.c:65:18: error: field has incomplete type

'enum CodecID'

enum CodecID codec_id;

[ismangil]

Patch to check ffmpeg version