Question on release 1.12: How to enable MSDK on Windows?

[Martin Maurer]

Hello,

first many thanks for the new release 1.12 of GStreamer.

In the release notes ( https://gstreamer.freedesktop.org/releases/1.12/ 
) there are the following entries:

In the highlights:

"new |msdk| plugin for Intel's Media SDK for hardware-accelerated video 
encoding and decoding on Intel graphics hardware on Windows or Linux."

In new elements:

"msdk: new plugin for Intel's Media SDK for hardware-accelerated video 
encoding and decoding on Intel graphics hardware on Windows or Linux. 
This includes an H.264 encoder/decoder (|msdkh264dec|, |msdkh264enc|), 
an H.265 encoder/decoder (|msdkh265dec|, |msdkh265enc|), an MJPEG 
encoder/encoder (|msdkmjpegdec|, |msdkmjpegenc|), an MPEG-2 video 
encoder (|msdkmpeg2enc|) and a VP8 encoder (|msdkvp8enc|)."

Can you describe how to enable it? It seems to be located in 
gst-plugins-bad. I have seen in configure.ac the following lines:

dnl check for intel mediasdk
translit(dnm, m, l) AM_CONDITIONAL(USE_MSDK, true)
AG_GST_CHECK_FEATURE(MSDK, [Intel MediaSDK], msdk, [
   AC_ARG_WITH([msdk-prefix],
           AS_HELP_STRING([--with-msdk-prefix],
           [Use the provided prefix for detecting the Intel MediaSDK]),
           [AS_IF([test "x$with_msdk_prefix" != "x"],
                  [MSDK_PREFIX="$with_msdk_prefix"])],
           [AS_IF([test "x$MFX_HOME" != "x"],
                  [MSDK_PREFIX="$MFX_HOME"],
                  [MSDK_PREFIX="/opt/intel/media"])])
   MSDK_CFLAGS="-I$MSDK_PREFIX/include"
   MSDK_LIBS="-L$MSDK_PREFIX/lib/lin_x64 -lmfx -ldl"
   AC_SUBST(MSDK_CFLAGS)
   AC_SUBST(MSDK_LIBS)

   save_CPPFLAGS="$CPPFLAGS"
   CPPFLAGS="$MSDK_CFLAGS $save_CPPFLAGS"
   AC_CHECK_HEADER(mfxdefs.h, HAVE_MFXDEFS_H="yes", HAVE_MFXDEFS_H="no")
   CPPFLAGS="$save_CPPFLAGS"

   save_LIBS="$LIBS"
   LIBS="$MSDK_LIBS $LIBS"
   AC_LANG_PUSH([C++])
   AC_CHECK_LIB(mfx,MFXInit,HAVE_MFX_LIB="yes",HAVE_MFX_LIB="no")
   AC_LANG_POP([C++])
   LIBS="$save_LIBS"

   PKG_CHECK_MODULES(LIBVA_DRM, libva-drm, HAVE_LIBVA_DRM="yes", 
HAVE_LIBVA_DRM="no")

   if test "x$HAVE_MFXDEFS_H" = "xyes" \
       -a "x$HAVE_MFX_LIB" = "xyes" \
       -a "x$HAVE_LIBVA_DRM" = "xyes"; then
     HAVE_MSDK="yes"
   else
     HAVE_MSDK="no"
   fi
])
AM_CONDITIONAL(USE_MSDK_LIBVA,
     test "x$HAVE_MSDK" = "xyes" -a "x$HAVE_LIBVA_DRM" = "xyes")


So it seems I had to add --with-msdk-prefix and let it point to Intel 
Media SDK,

which must be downloaded from Intel. I assume the Windows Version?

Where is the correct place to add --with-msdk-prefix? In the recipe of 
the gst-plugins-bad?

There is the following line:

   MSDK_LIBS="-L$MSDK_PREFIX/lib/lin_x64 -lmfx -ldl"

It looks like it is Linux dependant due to "lin" in "lin_x64". Are there 
always the Linux libraries used?

Shall/is "dl" available also on Windows?

It would be good to have a step-by-step instruction how to enable it. 
Can perhaps someone who has already built it shed light on how to do it?

Many, many thanks!

Best regards,

Martin