[ffmpeg] Add patch for upstream fixes

address build failures in pangolin that are related to updating
the ffmpeg library by pulling in pangolin fix from upstream.

ports/pangolin/CONTROL

@@ -1,4 +1,4 @@
 Source: pangolin
-Version: 0.5-3
+Version: 0.5-4
 Build-Depends: eigen3, glew, libpng, libjpeg-turbo, ffmpeg
 Description: Lightweight GUI Library

ports/pangolin/deprecated_constants.patch

@@ -0,0 +1,69 @@
+diff --git a/src/video/drivers/ffmpeg.cpp b/src/video/drivers/ffmpeg.cpp
+index 435225d..ff30349 100644
+--- a/src/video/drivers/ffmpeg.cpp
++++ b/src/video/drivers/ffmpeg.cpp
+@@ -34,6 +34,8 @@ extern "C"
+ #include <libavutil/mathematics.h>
+ }
+ 
++#define CODEC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
++
+ namespace pangolin
+ {
+ 
+@@ -74,8 +76,10 @@ std::string FfmpegFmtToString(const AVPixelFormat fmt)
+     TEST_PIX_FMT_RETURN(YUVJ420P);
+     TEST_PIX_FMT_RETURN(YUVJ422P);
+     TEST_PIX_FMT_RETURN(YUVJ444P);
++#ifdef FF_API_XVMC
+     TEST_PIX_FMT_RETURN(XVMC_MPEG2_MC);
+     TEST_PIX_FMT_RETURN(XVMC_MPEG2_IDCT);
++#endif
+     TEST_PIX_FMT_RETURN(UYVY422);
+     TEST_PIX_FMT_RETURN(UYYVYY411);
+     TEST_PIX_FMT_RETURN(BGR8);
+@@ -95,11 +99,13 @@ std::string FfmpegFmtToString(const AVPixelFormat fmt)
+     TEST_PIX_FMT_RETURN(YUV440P);
+     TEST_PIX_FMT_RETURN(YUVJ440P);
+     TEST_PIX_FMT_RETURN(YUVA420P);
++#ifdef FF_API_VDPAU
+     TEST_PIX_FMT_RETURN(VDPAU_H264);
+     TEST_PIX_FMT_RETURN(VDPAU_MPEG1);
+     TEST_PIX_FMT_RETURN(VDPAU_MPEG2);
+     TEST_PIX_FMT_RETURN(VDPAU_WMV3);
+     TEST_PIX_FMT_RETURN(VDPAU_VC1);
++#endif
+     TEST_PIX_FMT_RETURN(RGB48BE );
+     TEST_PIX_FMT_RETURN(RGB48LE );
+     TEST_PIX_FMT_RETURN(RGB565BE);
+@@ -119,7 +125,9 @@ std::string FfmpegFmtToString(const AVPixelFormat fmt)
+     TEST_PIX_FMT_RETURN(YUV422P16BE);
+     TEST_PIX_FMT_RETURN(YUV444P16LE);
+     TEST_PIX_FMT_RETURN(YUV444P16BE);
++#ifdef FF_API_VDPAU
+     TEST_PIX_FMT_RETURN(VDPAU_MPEG4);
++#endif
+     TEST_PIX_FMT_RETURN(DXVA2_VLD);
+     TEST_PIX_FMT_RETURN(RGB444BE);
+     TEST_PIX_FMT_RETURN(RGB444LE);
+@@ -559,7 +567,8 @@ void FfmpegVideoOutputStream::WriteFrame(AVFrame* frame)
+ 
+     int ret;
+     int got_packet = 1;
+-
++	
++#if FF_API_LAVF_FMT_RAWPICTURE
+     // Setup AVPacket
+     if (recorder.oc->oformat->flags & AVFMT_RAWPICTURE) {
+         /* Raw video case - directly store the picture in the packet */
+@@ -569,6 +578,10 @@ void FfmpegVideoOutputStream::WriteFrame(AVFrame* frame)
+         pkt.pts           = frame->pts;
+         ret = 0;
+     } else {
++#else
++    {
++#endif
++
+         /* encode the image */
+ #if (LIBAVFORMAT_VERSION_MAJOR >= 54)
+         ret = avcodec_encode_video2(stream->codec, &pkt, frame, &got_packet);

ports/pangolin/portfile.cmake

@@ -6,6 +6,7 @@ vcpkg_from_github(
     REF v0.5
     SHA512 7ebeec108f33f1aa8b1ad08e3ca128a837b22d33e3fc580021f981784043b023a1bf563bbfa8b51d46863db770b336d24fc84ee3d836b85e0da1848281b2a5b2
     HEAD_REF master
+	PATCHES deprecated_constants.patch # Change from upstream pangolin to address build failures from latest ffmpeg library
 )
 
 file(REMOVE ${SOURCE_PATH}/CMakeModules/FindGLEW.cmake)