[FFmpeg-devel] [PATCH] Made minor changes to get the decklink avdevice code to build using Visual C++

[Aaron Levinson]

>From aa549cf1c463f4a37bda44b934e17811986f11d9 Mon Sep 17 00:00:00 2001
From: Aaron Levinson <alevinsn at aracnet.com>
Date: Wed, 12 Apr 2017 20:21:41 -0700
Subject: [PATCH] Made minor changes to get the decklink avdevice code to build using Visual C++

Purpose: Made minor changes to get the decklink avdevice
 code to build using Visual C++.

Notes: Used Visual Studio 2015 (with update 3) for this.

Comments:

-- configure: For MSVC (Microsoft Visual C++) builds, now reinitializing
   decklink_indev_extralibs and decklink_outdev_extralibs to empty and
   then later, following the similar procedure used for mingw by
   adding -lole32 and -loleaut32.  This is necessary in order for it
   to link properly when building with Visual C++.

-- libavdevice/decklink_common.cpp: Switched the order of the include
   of libavformat/internal.h to workaround build issues with Visual
   C++.  See comment in file for more details.

-- libavdevice/decklink_dec.cpp:
a) Rearranged the include of libavformat/internal.h (for reasons as
   described above).
b) Made slight alteration to an argument for call to av_rescale_q() to
   workaround a compiler error with Visual C++.  This appears to only
   be an issue when building C++ files with Visual C++.  See comments
   in code for more details.

-- libavdevice/decklink_enc.cpp: Rearranged the include of
   libavformat/internal.h (for reasons as described above).
---
 configure                       |  4 ++++
 libavdevice/decklink_common.cpp | 10 +++++++++-
 libavdevice/decklink_dec.cpp    | 17 +++++++++++++++--
 libavdevice/decklink_enc.cpp    |  5 ++++-
 4 files changed, 32 insertions(+), 4 deletions(-)

diff --git a/configure b/configure
index adb0060..5b76a33 100755
--- a/configure
+++ b/configure
@@ -3646,6 +3646,8 @@ case "$toolchain" in
         ld_default="$source_path/compat/windows/mslink"
         nm_default="dumpbin -symbols"
         ar_default="lib"
+        decklink_indev_extralibs=""
+        decklink_outdev_extralibs=""
         case "$arch" in
         arm*)
             as_default="armasm"
@@ -4902,6 +4904,8 @@ case $target_os in
         fi
         enabled x86_32 && check_ldflags -LARGEADDRESSAWARE
         shlibdir_default="$bindir_default"
+        decklink_outdev_extralibs="$decklink_outdev_extralibs -lole32 -loleaut32"
+        decklink_indev_extralibs="$decklink_indev_extralibs -lole32 -loleaut32"
         SLIBPREF=""
         SLIBSUF=".dll"
         SLIBNAME_WITH_VERSION='$(SLIBPREF)$(FULLNAME)-$(LIBVERSION)$(SLIBSUF)'
diff --git a/libavdevice/decklink_common.cpp b/libavdevice/decklink_common.cpp
index f01fba9..523217c 100644
--- a/libavdevice/decklink_common.cpp
+++ b/libavdevice/decklink_common.cpp
@@ -19,6 +19,15 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+// Moved inclusion of internal.h here in order to get it to build successfully
+// when using Visual C++ to build--otherwise, compilation errors result
+// due to winsock.h (which is included indirectly by DeckLinkAPI.h and
+// DeckLinkAPI_i.c) conflicting with winsock2.h, which is included by
+// internal.h.  If winsock2.h is included first, then the conflict is resolved.
+extern "C" {
+#include "libavformat/internal.h"
+}
+
 #include <DeckLinkAPI.h>
 #ifdef _WIN32
 #include <DeckLinkAPI_i.c>
@@ -28,7 +37,6 @@
 
 extern "C" {
 #include "libavformat/avformat.h"
-#include "libavformat/internal.h"
 #include "libavutil/imgutils.h"
 #include "libavutil/intreadwrite.h"
 #include "libavutil/bswap.h"
diff --git a/libavdevice/decklink_dec.cpp b/libavdevice/decklink_dec.cpp
index 67eaf97..a663029 100644
--- a/libavdevice/decklink_dec.cpp
+++ b/libavdevice/decklink_dec.cpp
@@ -19,12 +19,15 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+extern "C" {
+#include "libavformat/internal.h"
+}
+
 #include <DeckLinkAPI.h>
 
 extern "C" {
 #include "config.h"
 #include "libavformat/avformat.h"
-#include "libavformat/internal.h"
 #include "libavutil/avutil.h"
 #include "libavutil/common.h"
 #include "libavutil/imgutils.h"
@@ -262,8 +265,18 @@ static int64_t get_pkt_pts(IDeckLinkVideoInputFrame *videoFrame,
                 res = videoFrame->GetHardwareReferenceTimestamp(time_base.den, &bmd_pts, &bmd_duration);
             break;
         case PTS_SRC_WALLCLOCK:
-            pts = av_rescale_q(wallclock, AV_TIME_BASE_Q, time_base);
+        {
+            // doing the following rather than using AV_TIME_BASE_Q because
+            // AV_TIME_BASE_Q doesn't work when building with Visual C++
+            // for C++ files (works for C files).  When building C++ files,
+            // it results in compiler error C4576.  At least, this is the case
+            // with Visual C++ 2015.
+            AVRational timebase;
+            timebase.num = 1;
+            timebase.den = AV_TIME_BASE;
+            pts = av_rescale_q(wallclock, timebase, time_base);
             break;
+        }
     }
     if (res == S_OK)
         pts = bmd_pts / time_base.num;
diff --git a/libavdevice/decklink_enc.cpp b/libavdevice/decklink_enc.cpp
index 5105967..3bd6357 100644
--- a/libavdevice/decklink_enc.cpp
+++ b/libavdevice/decklink_enc.cpp
@@ -22,11 +22,14 @@
 #include <atomic>
 using std::atomic;
 
+extern "C" {
+#include "libavformat/internal.h"
+}
+
 #include <DeckLinkAPI.h>
 
 extern "C" {
 #include "libavformat/avformat.h"
-#include "libavformat/internal.h"
 #include "libavutil/imgutils.h"
 }
 
-- 
2.10.1.windows.1