Error in building opencv with ffmpeg - c++

Question

I installed ffmpeg according to this article. ffmpeg installation was ok.
Now I build opencv with ffmpeg support and I have some errors.
The errors are
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp:1484:21: error: ‘CODEC_FLAG_GLOBAL_HEADER’ was not declared in this scope
c->flags |= CODEC_FLAG_GLOBAL_HEADER;
^
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp: In function ‘int icv_av_write_frame_FFMPEG(AVFormatContext*, AVStream*, uint8_t*, uint32_t, AVFrame*)’:
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp:1512:30: error: ‘AVFMT_RAWPICTURE’ was not declared in this scope
if (oc->oformat->flags & AVFMT_RAWPICTURE) {
^
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp: In member function ‘void CvVideoWriter_FFMPEG::close()’:
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp:1686:35: error: ‘AVFMT_RAWPICTURE’ was not declared in this scope
if( (oc->oformat->flags & AVFMT_RAWPICTURE) == 0 )
^
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp: In member function ‘bool CvVideoWriter_FFMPEG::open(const char*, int, double, int, int, bool)’:
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp:1920:32: error: ‘AVFMT_RAWPICTURE’ was not declared in this scope
if (!(oc->oformat->flags & AVFMT_RAWPICTURE)) {
^
In file included from /home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg.cpp:45:0:
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp: In static member function ‘static AVStream* OutputMediaStream_FFMPEG::addVideoStream(AVFormatContext*, AVCodecID, int, int, int, double, AVPixelFormat)’:
/home/coie/Softwares/Libraries/opencv-2.4.13.3/modules/highgui/src/cap_ffmpeg_impl.hpp:2214:25: error: ‘CODEC_FLAG_GLOBAL_HEADER’ was not declared in this scope
c->flags |= CODEC_FLAG_GLOBAL_HEADER;
^
modules/highgui/CMakeFiles/opencv_highgui.dir/build.make:230: recipe for target 'modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_ffmpeg.cpp.o' failed
make[2]: *** [modules/highgui/CMakeFiles/opencv_highgui.dir/src/cap_ffmpeg.cpp.o] Error 1
CMakeFiles/Makefile2:2349: recipe for target 'modules/highgui/CMakeFiles/opencv_highgui.dir/all' failed
What could be wrong?

Answer 1

My solution is to grep the missing defines (2 in total) from FFmpeg by using grep -r which leads to the following code found in libavcodec/avcodec.h:
#define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
#define CODEC_FLAG_GLOBAL_HEADER AV_CODEC_FLAG_GLOBAL_HEADER
#define AVFMT_RAWPICTURE 0x0020
Copy and paste it to the top of:
opencv-3.3.0/modules/videoio/src/cap_ffmpeg_impl.hpp
Compile and everything works even with the latest sources

Answer 2

Easiest change for the CODEC_FLAG_GLOBAL_HEADER is to change it to AV_CODEC_FLAG_GLOBAL_HEADER, it was redefined in a newer version.
Note the "AV_" in front

Answer 3

in opencv:0/2.4 there is no modules/videoio directory! to get that old version (2.4.13-r3) to compile with newest media-video/ffmpeg on gentoo (4.1.3) I had to add above changes to modules/highgui/src/cap_ffmpeg_api.hpp with this
patch:
--- opencv-2.4.13/modules/highgui/src/cap_ffmpeg_api.hpp 2019-05-27 13:28:05.736339890 +0200
+++ opencv-2.4.13-new/modules/highgui/src/cap_ffmpeg_api.hpp 2019-05-27 13:27:48.787198507 +0200
## -12,6 +12,10 ##
#define OPENCV_FFMPEG_API
#endif
+#define AV_CODEC_FLAG_GLOBAL_HEADER (1 << 22)
+#define CODEC_FLAG_GLOBAL_HEADER
AV_CODEC_FLAG_GLOBAL_HEADER
+#define AVFMT_RAWPICTURE 0x0020
+
enum
{
CV_FFMPEG_CAP_PROP_POS_MSEC=0,
(i.e. I created the path and file /etc/portage/patches/media-libs/opencv-2.4.13-r3/old-ffmpeg.patch with that contents.)
in defense to gentoo, I should mention, the new media-libs/opencv:0/3.4.1 is also available, as is the old media-video/ffmpeg-3.4.5, so I could alternatively also play around with masking out versions or file a bug for developers to do that for me...