multiple definition of `_DXVA2_Fixed32OpaqueAlpha'

[Kyle]

I'm getting the following error while trying to compile the latest FFmpeg with MinGW-w64:

libavcodec/libavcodec.a(dxva2_mpeg2.o):dxva2_mpeg2.c:(.text+0x7d0): multiple definition of `_DXVA2_Fixed32OpaqueAlpha'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x1870): first defined here
libavcodec/libavcodec.a(dxva2_mpeg2.o):dxva2_mpeg2.c:(.text+0x7e0): multiple definition of `_DXVA2_Fixed32TransparentAlpha'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x1880): first defined here
libavcodec/libavcodec.a(dxva2_mpeg2.o):dxva2_mpeg2.c:(.text+0x7f0): multiple definition of `_DXVA2FixedToFloat'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x1890): first defined here
libavcodec/libavcodec.a(dxva2_mpeg2.o):dxva2_mpeg2.c:(.text+0x830): multiple definition of `_DXVA2FloatToFixed'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x18d0): first defined here
libavcodec/libavcodec.a(dxva2.o):dxva2.c:(.text+0x170): multiple definition of `_DXVA2_Fixed32OpaqueAlpha'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x1870): first defined here
libavcodec/libavcodec.a(dxva2.o):dxva2.c:(.text+0x180): multiple definition of `_DXVA2_Fixed32TransparentAlpha'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x1880): first defined here
libavcodec/libavcodec.a(dxva2.o):dxva2.c:(.text+0x190): multiple definition of `_DXVA2FixedToFloat'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x1890): first defined here
libavcodec/libavcodec.a(dxva2.o):dxva2.c:(.text+0x1d0): multiple definition of `_DXVA2FloatToFixed'
libavcodec/libavcodec.a(dxva2_h264.o):dxva2_h264.c:(.text+0x18d0): first defined here
collect2: ld returned 1 exit status
make: *** [ffmpeg_g.exe] Error 1

make V=1 shows:

i686-w64-mingw32-gcc -Llibavcodec -Llibavdevice -Llibavfilter -Llibavformat -Llibavutil -Llibpostproc -Llibswscale -Wl,--as-needed -Wl,--warn-common -Wl,-rpath-link=libpostproc:libswscale:libavfilter:libavdevice:libavformat:libavcodec:libavutil -o ffmpeg_g.exe ffmpeg.o cmdutils.o -lavdevice -lavfilter -lavformat -lavcodec -lpostproc -lswscale -lavutil -lavicap32 -lpsapi -lole32 -lstrmiids -luuid -lws2_32 -lm -lpthread -lpsapi

I'm using GCC 4.6.1 to compile, I believe the issue could be on MinGW-w64s end, but I'm not sure because I had no other issues compiling other software with the toolchain.

[Carl Eugen Hoyos]

Does it work without --enable-shared?

Am I correct that the problem is related to <dxva2api.h>? (Are the symbols in question defined there?)
If yes, could you attach the header?

[Kyle]

--enable-shared was not used, this is the command line used to configure:

../source/ffmpeg-git/configure --enable-gpl --enable-version3 --enable-runtime-cpudetect --cross-prefix=i686-w64-mingw32- --target-os=mingw32 --arch=x86 --disable-debug

I'm not sure if it's directly related to dxva2api.h, DXVA2_Fixed32OpaqueAlpha can be found inside.

Header attached.

[Carl Eugen Hoyos]

Afaict, the functions (that currently only use forceinline) defined in dxva2api.h all have to be defined "static" (as it is done in many internal FFmpeg headers, for example libavformat/network.h).

Could you report this to the w64 mingw-runtime developers?
(Or am I missing something?)

An alternative would be be to try

#undef __forceinline
#define __forceinline static av_always_inline

before including the header.

[Kyle]

I contacted mingw-w64, they say a fix is on the way.

I'll report back once I have a successful build and this bug can be resolved.

[Kyle]

This bug has been resolved.