[FFmpeg-devel] [PATCH] Made minor changes to get the decklink avdevice code to build using Visual C++
Aaron Levinson
alevinsn at aracnet.com
Fri Apr 14 00:32:52 EEST 2017
On 4/13/2017 1:23 PM, Hendrik Leppkes wrote:
> On Thu, Apr 13, 2017 at 10:09 PM, Aaron Levinson <alevinsn at aracnet.com> wrote:
>> On 4/13/2017 3:55 AM, Hendrik Leppkes wrote:
>>>
>>> On Thu, Apr 13, 2017 at 12:39 PM, Aaron Levinson <alevinsn at aracnet.com>
>>> wrote:
>>>>
>>>> On 4/13/2017 12:36 AM, Hendrik Leppkes wrote:
>>>> diff --git a/configure b/configure
>>>> index a383bf2..9a06437 100755
>>>> --- a/configure
>>>> +++ b/configure
>>>> @@ -4843,8 +4843,6 @@ case $target_os in
>>>> else
>>>> target_os=mingw32
>>>> fi
>>>> - decklink_outdev_extralibs="$decklink_outdev_extralibs -lole32
>>>> -loleaut32"
>>>> - decklink_indev_extralibs="$decklink_indev_extralibs -lole32
>>>> -loleaut32"
>>>> LIBTARGET=i386
>>>> if enabled x86_64; then
>>>> LIBTARGET="i386:x86-64"
>>>> @@ -5946,6 +5944,19 @@ if ! disabled sdl2; then
>>>> fi
>>>> enabled sdl2 && enable sdl && add_cflags $sdl2_cflags && add_extralibs
>>>> $sdl2_libs
>>>>
>>>> +if enabled decklink; then
>>>> + case $target_os in
>>>> + mingw32*|mingw64*)
>>>> + decklink_outdev_extralibs="$decklink_outdev_extralibs
>>>> -lole32 -loleaut32"
>>>> + decklink_indev_extralibs="$decklink_indev_extralibs -lole32
>>>> -loleaut32"
>>>> + ;;
>>>> + win32|win64)
>>>> + decklink_outdev_extralibs="-lole32 -loleaut32"
>>>> + decklink_indev_extralibs="-lole32 -loleaut32"
>>>> + ;;
>>>> + esac
>>>> +fi
>>>> +
>>>
>>>
>>> Whats in the extralibs before this block that you need to clear out in
>>> the msvc case?
>>> Maybe that part should just be set conditionally so we can unify this,
>>> and don't set something we need to strip out again after.
>>>
>>> - Hendrik
>>
>>
>> decklink_outdev_extralibs and decklink_indev_extralibs are declared as
>> follows earlier in configure:
>>
>> decklink_indev_extralibs="-lstdc++"
>> decklink_outdev_extralibs="-lstdc++"
>>
>> This is done in the standard section where
>> <library>_<indev|outdev>_<extralibs|deps> can be found.
>>
>> libstdc++ is needed when building the Decklink source files with gcc/g++
>> because of, at a minimum, the use of STL in one of the .cpp files.
>>
>> For builds targeting Windows, -lole32 and -loleaut32 are also needed because
>> of the use of COM. So, that explains why -lole32 and -loleaut32 are added
>> for both mingw and Windows.
>>
>> Finally, when building with the Microsoft compiler (cl.exe), libstdc++ is
>> not needed and actually can't be found. The C/C++ run-time is included by
>> default in some form when building with cl.exe unless the -nodefaultlib
>> linker option is used. So, that explains why it replaces the extralibs
>> variables with just -lole32 and -loleaut32 for Windows builds. Note that
>> win32 to specified as the target_os when an msvc build is done, and it may
>> be the only case when target_os is set to win32 unless the user manually
>> sets it as an option when invoking configure.
>>
>> -lole32 and -loleaut32 is likely relevant for both cygwin and the Intel
>> compiler, but it should be a simple matter to add those later if anyone uses
>> those for building. The elimination of -lstdc++ may also be relevant for
>> the Intel compiler but probably only when using the Intel compiler on
>> Windows.
>>
>> Anyway, I don't think an approach that moves -lstdc++ into the above if
>> block is any better or worse than the patch in its current form, and the
>> patch in its current form results in fewer changes to configure than a patch
>> that moves -lstdc++ around.
>>
>
> You could add -lstdc++ to the msvc flag filter (ie.
> msvc_common_flags), since its never needed, and may be added by more
> things in the future, that would solve all of those neatly.
>
> - Hendrik
That's a good idea and is cleaner and more general than the approach I had used. Here's a new version of the patch, although it is my understanding that you may push the -lstdc++ change in msvc_common_flags() as part of another patch, but regardless, a new patch for this is needed.
--------------------------------------------------------------------------------------------
>From 00fdc9d15414a92a155eb7d1394bac3736dc9405 Mon Sep 17 00:00:00 2001
From: Aaron Levinson <alevinsn at aracnet.com>
Date: Thu, 13 Apr 2017 14:22:19 -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. Also made
changes to configure per Hendrik Leppkes's review of first and second
versions of patch.
Comments:
-- configure:
a) Added replacement of -lstdc++ with nothing in msvc_common_flags()
since the C++ standard library is included by default for MSVC
builds as part of the C/C++ run-time. Also, MSVC builds will fail
when -lstdc++ is used.
b) Added if enabled decklink section and setting
decklink_indev_extralibs and decklink_outdev_extralibs here for
both mingw and Windows. Also eliminated the setting of these
variables in the mingw section earlier in the file.
-- 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 | 12 ++++++++++--
libavdevice/decklink_common.cpp | 10 +++++++++-
libavdevice/decklink_dec.cpp | 17 +++++++++++++++--
libavdevice/decklink_enc.cpp | 5 ++++-
4 files changed, 38 insertions(+), 6 deletions(-)
diff --git a/configure b/configure
index a383bf2..684650a 100755
--- a/configure
+++ b/configure
@@ -3851,6 +3851,7 @@ msvc_common_flags(){
-lz) echo zlib.lib ;;
-lavicap32) echo vfw32.lib user32.lib ;;
-lx264) echo libx264.lib ;;
+ -lstdc++) ;;
-l*) echo ${flag#-l}.lib ;;
-LARGEADDRESSAWARE) echo $flag ;;
-L*) echo -libpath:${flag#-L} ;;
@@ -4843,8 +4844,6 @@ case $target_os in
else
target_os=mingw32
fi
- decklink_outdev_extralibs="$decklink_outdev_extralibs -lole32 -loleaut32"
- decklink_indev_extralibs="$decklink_indev_extralibs -lole32 -loleaut32"
LIBTARGET=i386
if enabled x86_64; then
LIBTARGET="i386:x86-64"
@@ -5946,6 +5945,15 @@ if ! disabled sdl2; then
fi
enabled sdl2 && enable sdl && add_cflags $sdl2_cflags && add_extralibs $sdl2_libs
+if enabled decklink; then
+ case $target_os in
+ mingw32*|mingw64*|win32|win64)
+ decklink_outdev_extralibs="$decklink_outdev_extralibs -lole32 -loleaut32"
+ decklink_indev_extralibs="$decklink_indev_extralibs -lole32 -loleaut32"
+ ;;
+ esac
+fi
+
disabled securetransport || { check_func SecIdentityCreate "-Wl,-framework,CoreFoundation -Wl,-framework,Security" &&
check_lib "Security/SecureTransport.h Security/Security.h" "SSLCreateContext SecItemImport" "-Wl,-framework,CoreFoundation -Wl,-framework,Security" &&
enable securetransport; }
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
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