opencv4.patch

--- ffmpeg-4.3.2/configure~	2021-02-20 21:27:47.000000000 +0100
+++ ffmpeg-4.3.2/configure	2021-03-06 22:46:31.336556852 +0100
@@ -6340,9 +6340,9 @@
 enabled libopencore_amrnb && require libopencore_amrnb opencore-amrnb/interf_dec.h Decoder_Interface_init -lopencore-amrnb
 enabled libopencore_amrwb && require libopencore_amrwb opencore-amrwb/dec_if.h D_IF_init -lopencore-amrwb
 enabled libopencv         && { check_headers opencv2/core/core_c.h &&
-                               { check_pkg_config libopencv opencv opencv2/core/core_c.h cvCreateImageHeader ||
+                               { check_pkg_config libopencv opencv4 opencv2/core/core_c.h cvCreateImageHeader ||
                                  require libopencv opencv2/core/core_c.h cvCreateImageHeader -lopencv_core -lopencv_imgproc; } ||
-                               require_pkg_config libopencv opencv opencv/cxcore.h cvCreateImageHeader; }
+                               require_pkg_config libopencv opencv4 opencv/cxcore.h cvCreateImageHeader; }
 enabled libopenh264       && require_pkg_config libopenh264 openh264 wels/codec_api.h WelsGetCodecVersion
 enabled libopenjpeg       && { check_pkg_config libopenjpeg "libopenjp2 >= 2.1.0" openjpeg.h opj_version ||
                                { require_pkg_config libopenjpeg "libopenjp2 >= 2.1.0" openjpeg.h opj_version -DOPJ_STATIC && add_cppflags -DOPJ_STATIC; } }