build: restore videotoolbox compilation on iOS

configure

@@ -1818,6 +1818,7 @@ SYSTEM_FUNCS="
     sysconf
     sysctl
     usleep
+    UTGetOSTypeFromString
     VirtualAlloc
     wglGetProcAddress
 "
@@ -2395,11 +2396,11 @@ crystalhd_deps="libcrystalhd_libcrystalhd_if_h"
 d3d11va_deps="d3d11_h dxva_h ID3D11VideoDecoder ID3D11VideoContext"
 dxva2_deps="dxva2api_h DXVA2_ConfigPictureDecode"
 vaapi_deps="va_va_h"
-vda_deps="VideoDecodeAcceleration_VDADecoder_h pthreads CoreServices_CoreServices_h"
-vda_extralibs="-framework CoreFoundation -framework VideoDecodeAcceleration -framework QuartzCore -framework CoreServices"
+vda_deps="VideoDecodeAcceleration_VDADecoder_h pthreads"
+vda_extralibs="-framework CoreFoundation -framework VideoDecodeAcceleration -framework QuartzCore"
 vdpau_deps="vdpau_vdpau_h vdpau_vdpau_x11_h"
-videotoolbox_deps="VideoToolbox_VideoToolbox_h pthreads CoreServices_CoreServices_h"
-videotoolbox_extralibs="-framework CoreFoundation -framework VideoToolbox -framework CoreMedia -framework QuartzCore -framework CoreServices"
+videotoolbox_deps="VideoToolbox_VideoToolbox_h pthreads"
+videotoolbox_extralibs="-framework CoreFoundation -framework VideoToolbox -framework CoreMedia -framework QuartzCore"
 xvmc_deps="X11_extensions_XvMClib_h"
 
 h263_vaapi_hwaccel_deps="vaapi"
@@ -5157,7 +5158,6 @@ check_func_headers glob.h glob
 enabled xlib &&
     check_func_headers "X11/Xlib.h X11/extensions/Xvlib.h" XvGetPortAttribute -lXv -lX11 -lXext
 
-check_header CoreServices/CoreServices.h
 check_header direct.h
 check_header dirent.h
 check_header dlfcn.h
@@ -5190,6 +5190,7 @@ check_header asm/types.h
 check_lib2 "windows.h shellapi.h" CommandLineToArgvW -lshell32
 check_lib2 "windows.h wincrypt.h" CryptGenRandom -ladvapi32
 check_lib2 "windows.h psapi.h" GetProcessMemoryInfo -lpsapi
+check_lib "CoreServices/CoreServices.h" UTGetOSTypeFromString "-framework CoreServices"
 
 check_struct "sys/time.h sys/resource.h" "struct rusage" ru_maxrss
 

ffmpeg_videotoolbox.c

@@ -16,7 +16,9 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#if HAVE_UTGETOSTYPEFROMSTRING
 #include <CoreServices/CoreServices.h>
+#endif
 
 #include "config.h"
 #include "libavcodec/avcodec.h"
@@ -168,7 +170,13 @@ int videotoolbox_init(AVCodecContext *s)
             CFStringRef pixfmt_str = CFStringCreateWithCString(kCFAllocatorDefault,
                                                                videotoolbox_pixfmt,
                                                                kCFStringEncodingUTF8);
+#if HAVE_UTGETOSTYPEFROMSTRING
             vdactx->cv_pix_fmt_type = UTGetOSTypeFromString(pixfmt_str);
+#else
+            av_log(s, loglevel, "UTGetOSTypeFromString() is not available "
+                   "on this platform, %s pixel format can not be honored from "
+                   "the command line\n", videotoolbox_pixfmt);
+#endif
             ret = av_vda_default_init2(s, vdactx);
             CFRelease(pixfmt_str);
         }