lavc/videotoolboxenc: add hdr10, linear, hlg color transfer function for videotoolboxenc

Below is the testing ffmpeg command for the setting:
./ffmpeg -i input.ts -c:v hevc_videotoolbox -color_primaries bt2020 -colorspace bt2020_ncl -color_trc smpte2084 smpte2048.ts
./ffmpeg -i input.ts -c:v hevc_videotoolbox -color_primaries bt2020 -colorspace bt2020_ncl -color_trc linear linear.ts
./ffmpeg -i input.ts -c:v hevc_videotoolbox -color_primaries bt2020 -colorspace bt2020_ncl -color_trc arib-std-b67 hlg.ts

Signed-off-by: Limin Wang <lance.lmwang@gmail.com>
Signed-off-by: Rick Kern <kernrj@gmail.com>

configure

@@ -2268,6 +2268,9 @@ TOOLCHAIN_FEATURES="
 TYPES_LIST="
     kCMVideoCodecType_HEVC
     kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange
+    kCVImageBufferTransferFunction_SMPTE_ST_2084_PQ
+    kCVImageBufferTransferFunction_ITU_R_2100_HLG
+    kCVImageBufferTransferFunction_Linear
     socklen_t
     struct_addrinfo
     struct_group_source_req
@@ -6069,6 +6072,9 @@ enabled videotoolbox && {
     check_lib coreservices CoreServices/CoreServices.h UTGetOSTypeFromString "-framework CoreServices"
     check_func_headers CoreMedia/CMFormatDescription.h kCMVideoCodecType_HEVC "-framework CoreMedia"
     check_func_headers CoreVideo/CVPixelBuffer.h kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange "-framework CoreVideo"
+    check_func_headers CoreVideo/CVImageBuffer.h kCVImageBufferTransferFunction_SMPTE_ST_2084_PQ "-framework CoreVideo"
+    check_func_headers CoreVideo/CVImageBuffer.h kCVImageBufferTransferFunction_ITU_R_2100_HLG "-framework CoreVideo"
+    check_func_headers CoreVideo/CVImageBuffer.h kCVImageBufferTransferFunction_Linear "-framework CoreVideo"
 }
 
 check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss

libavcodec/videotoolboxenc.c

@@ -915,6 +915,22 @@ static int get_cv_transfer_function(AVCodecContext *avctx,
             *transfer_fnc = kCVImageBufferTransferFunction_SMPTE_240M_1995;
             break;
 
+#if HAVE_KCVIMAGEBUFFERTRANSFERFUNCTION_SMPTE_ST_2084_PQ
+        case AVCOL_TRC_SMPTE2084:
+            *transfer_fnc = kCVImageBufferTransferFunction_SMPTE_ST_2084_PQ;
+            break;
+#endif
+#if HAVE_KCVIMAGEBUFFERTRANSFERFUNCTION_LINEAR
+        case AVCOL_TRC_LINEAR:
+            *transfer_fnc = kCVImageBufferTransferFunction_Linear;
+            break;
+#endif
+#if HAVE_KCVIMAGEBUFFERTRANSFERFUNCTION_ITU_R_2100_HLG
+        case AVCOL_TRC_ARIB_STD_B67:
+            *transfer_fnc = kCVImageBufferTransferFunction_ITU_R_2100_HLG;
+            break;
+#endif
+
         case AVCOL_TRC_GAMMA22:
             gamma = 2.2;
             *transfer_fnc = kCVImageBufferTransferFunction_UseGamma;