avcodec/nvenc: include nvEncodeAPI v7 SDK header

As Nvidia has put the most recent Video Codec SDK behind a double
registration wall, of which one needs manual approval of a lenghty
application, bundling this header saves everyone trying to use NVENC
from that headache.

The header is still MIT licensed and thus fine to bundle with ffmpeg.

Not bundling this header would get ffmpeg stuck at SDK v6, which is
still freely available, holding back future development of the NVENC
encoder.

configure

@@ -307,7 +307,7 @@ External library support:
   --enable-libmfx          enable Intel MediaSDK (AKA Quick Sync Video) code via libmfx [no]
   --enable-libnpp          enable Nvidia Performance Primitives-based code [no]
   --enable-mmal            enable Broadcom Multi-Media Abstraction Layer (Raspberry Pi) via MMAL [no]
-  --enable-nvenc           enable Nvidia video encoding code [no]
+  --disable-nvenc          disable Nvidia video encoding code [autodetect]
   --enable-omx             enable OpenMAX IL code [no]
   --enable-omx-rpi         enable OpenMAX IL code for Raspberry Pi [no]
   --disable-vaapi          disable Video Acceleration API (mainly Unix/Intel) code [autodetect]
@@ -5777,10 +5777,6 @@ enabled mmal              && { check_lib interface/mmal/mmal.h mmal_port_connect
 enabled mmal && check_func_headers interface/mmal/mmal.h "MMAL_PARAMETER_VIDEO_MAX_NUM_CALLBACKS"
 
 enabled netcdf            && require_pkg_config netcdf netcdf.h nc_inq_libvers
-enabled nvenc             && { check_header nvEncodeAPI.h || die "ERROR: nvEncodeAPI.h not found."; } &&
-                             { check_cpp_condition nvEncodeAPI.h "NVENCAPI_MAJOR_VERSION >= 6" ||
-                               die "ERROR: NVENC API version 5 or older is not supported"; } &&
-                             { [ $target_os != cygwin ] || die "ERROR: NVENC is not supported on Cygwin currently."; }
 enabled openal            && { { for al_libs in "${OPENAL_LIBS}" "-lopenal" "-lOpenAL32"; do
                                check_lib 'AL/al.h' alGetError "${al_libs}" && break; done } ||
                                die "ERROR: openal not found"; } &&
@@ -5996,6 +5992,22 @@ enabled vdpau && enabled xlib &&
     check_lib2 "vdpau/vdpau.h vdpau/vdpau_x11.h" vdp_device_create_x11 -lvdpau &&
     enable vdpau_x11
 
+case $target_os in
+    mingw32*|mingw64*|win32|win64|linux|cygwin*)
+        disabled nvenc || enable nvenc
+        ;;
+    *)
+        disable nvenc
+        ;;
+esac
+
+if enabled nvenc; then
+    {
+        echo '#include "compat/nvenc/nvEncodeAPI.h"'
+        echo 'int main(void) { return 0; }'
+    } | check_cc -I$source_path || disable nvenc
+fi
+
 # Funny iconv installations are not unusual, so check it after all flags have been set
 disabled iconv || check_func_headers iconv.h iconv || check_lib2 iconv.h iconv -liconv || disable iconv
 

libavcodec/nvenc.h

@@ -19,7 +19,7 @@
 #ifndef AVCODEC_NVENC_H
 #define AVCODEC_NVENC_H
 
-#include <nvEncodeAPI.h>
+#include "compat/nvenc/nvEncodeAPI.h"
 
 #include "config.h"
 

tests/ref/fate/source

@@ -26,3 +26,4 @@ compat/avisynth/windowsPorts/basicDataTypeConversions.h
 compat/avisynth/windowsPorts/windows2linux.h
 compat/float/float.h
 compat/float/limits.h
+compat/nvenc/nvEncodeAPI.h