examples: use function to get iface pointers

MSVC can't pass the address of global variables in a DLL correctly
across DLL boundaries. This patch allows linking the examples to
a libvpx dll build. Fixes issue #268.

Change-Id: I1c52d076cfc68efb3efdfba019f12d53c5019f58

examples/decoder_tmpl.c

@@ -19,7 +19,7 @@
 #define VPX_CODEC_DISABLE_COMPAT 1
 #include "vpx/vpx_decoder.h"
 #include "vpx/vp8dx.h"
-#define interface (&vpx_codec_vp8_dx_algo)
+#define interface (vpx_codec_vp8_dx())
 @EXTRA_INCLUDES
 
 

examples/decoder_tmpl.txt

@@ -2,7 +2,7 @@
 #define VPX_CODEC_DISABLE_COMPAT 1
 #include "vpx/vpx_decoder.h"
 #include "vpx/vp8dx.h"
-#define interface (&vpx_codec_vp8_dx_algo)
+#define interface (vpx_codec_vp8_dx())
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ DEC_INCLUDES
 
 

examples/encoder_tmpl.c

@@ -19,7 +19,7 @@
 #define VPX_CODEC_DISABLE_COMPAT 1
 #include "vpx/vpx_encoder.h"
 #include "vpx/vp8cx.h"
-#define interface (&vpx_codec_vp8_cx_algo)
+#define interface (vpx_codec_vp8_cx())
 #define fourcc    0x30385056
 @EXTRA_INCLUDES
 

examples/encoder_tmpl.txt

@@ -2,7 +2,7 @@
 #define VPX_CODEC_DISABLE_COMPAT 1
 #include "vpx/vpx_encoder.h"
 #include "vpx/vp8cx.h"
-#define interface (&vpx_codec_vp8_cx_algo)
+#define interface (vpx_codec_vp8_cx())
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ENC_INCLUDES
 
 

examples/simple_decoder.txt

@@ -33,7 +33,7 @@ Initializing The Codec
 ----------------------
 The decoder is initialized by the following code. This is an example for
 the VP8 decoder, but the code is analogous for all algorithms. Replace
-`&vpx_codec_vp8_dx_algo` with a pointer to the interface exposed by the
+`vpx_codec_vp8_dx()` with a pointer to the interface exposed by the
 algorithm you want to use. The `cfg` argument is left as NULL in this
 example, because we want the algorithm to determine the stream
 configuration (width/height) and allocate memory automatically. This