avconv: add support for DXVA2 decoding

Signed-off-by: Anton Khirnov <[email protected]>
diff --git a/avconv_opt.c b/avconv_opt.c
index fc57f6b..6015183 100644
--- a/avconv_opt.c
+++ b/avconv_opt.c
@@ -57,6 +57,9 @@
 #if HAVE_VDPAU_X11
     { "vdpau", vdpau_init, HWACCEL_VDPAU, AV_PIX_FMT_VDPAU },
 #endif
+#if CONFIG_DXVA2
+    { "dxva2", dxva2_init, HWACCEL_DXVA2, AV_PIX_FMT_DXVA2_VLD },
+#endif
     { 0 },
 };