codec: videotoolbox: Check wherever a metal device can be fetched on iOS

Metal device is mandatory to handle P010 chroma on mobile/tv devices.
The Metal device API can only be used in ObjC context hence a new ObjC source file had to be created to handle the device detection.

modules/codec/Makefile.am

@@ -352,7 +352,7 @@ codec_LTLIBRARIES += $(LTLIBoggspots)
 
 libvideotoolbox_plugin_la_SOURCES = codec/videotoolbox/decoder.c
 libvideotoolbox_plugin_la_LIBADD = libchroma_copy.la libvlc_hxxxhelper.la libvlc_vtutils.la
-libvideotoolbox_plugin_la_LDFLAGS = $(AM_LDFLAGS) -Wl,-framework,CoreFoundation -Wl,-framework,VideoToolbox -Wl,-framework,CoreMedia -Wl,-framework,CoreVideo
+libvideotoolbox_plugin_la_LDFLAGS = $(AM_LDFLAGS) -Wl,-framework,CoreFoundation -Wl,-framework,VideoToolbox -Wl,-framework,CoreMedia -Wl,-framework,CoreVideo -Wl,-framework,Metal
 if HAVE_DARWIN
 codec_LTLIBRARIES += libvideotoolbox_plugin.la
 endif
@@ -360,7 +360,7 @@ endif
 libvideotoolbox_enc_plugin_la_SOURCES = codec/videotoolbox/encoder.c
 libvideotoolbox_enc_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) # Trigger MODULE_NAME declaration
 libvideotoolbox_enc_plugin_la_LIBADD = libvlc_hxxxhelper.la libvlc_vtutils.la
-libvideotoolbox_enc_plugin_la_LDFLAGS = $(AM_LDFLAGS) -Wl,-framework,CoreFoundation -Wl,-framework,VideoToolbox -Wl,-framework,CoreMedia -Wl,-framework,CoreVideo
+libvideotoolbox_enc_plugin_la_LDFLAGS = $(AM_LDFLAGS) -Wl,-framework,CoreFoundation -Wl,-framework,VideoToolbox -Wl,-framework,CoreMedia -Wl,-framework,CoreVideo -Wl,-framework,Metal
 if HAVE_DARWIN
 if ENABLE_SOUT
 codec_LTLIBRARIES += libvideotoolbox_enc_plugin.la
@@ -652,6 +652,6 @@ libhxxxhelper_testdec_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(codecdir)'
 libhxxxhelper_testdec_plugin_la_LIBADD = libvlc_hxxxhelper.la
 noinst_LTLIBRARIES += libhxxxhelper_testdec_plugin.la
 
-libvlc_vtutils_la_SOURCES = codec/vt_utils.c codec/vt_utils.h
+libvlc_vtutils_la_SOURCES = codec/vt_utils.c codec/vt_utils.h codec/vt_utils_native.m
 libvlc_vtutils_la_LDFLAGS = -static -no-undefined
 EXTRA_LTLIBRARIES += libvlc_vtutils.la

modules/codec/videotoolbox/decoder.c

@@ -73,6 +73,7 @@ static void Drain(decoder_t *p_dec, bool flush);
 static void DecoderCallback(void *, void *, OSStatus, VTDecodeInfoFlags,
                             CVPixelBufferRef, CMTime, CMTime);
 static Boolean deviceSupportsHEVC();
+static bool deviceSupports42010bitRendering();
 static Boolean deviceSupportsAdvancedProfiles();
 static Boolean deviceSupportsAdvancedLevels();
 
@@ -252,7 +253,7 @@ static OSType GetBestChroma(uint8_t i_chroma_format, uint8_t i_depth_luma,
             return kCVPixelFormatType_420YpCbCr8BiPlanarVideoRange;
         if (i_depth_luma == 10 && i_depth_chroma == 10)
         {
-            if (deviceSupportsHEVC()) /* 42010bit went with HEVC on macOS */
+            if (deviceSupportsHEVC() && deviceSupports42010bitRendering())
                 return kCVPixelFormatType_420YpCbCr10BiPlanarVideoRange;
 
            /* Force BGRA output (and let VT handle the tone mapping) since the
@@ -1633,6 +1634,17 @@ static Boolean deviceSupportsHEVC()
         return false;
 }
 
+static bool deviceSupports42010bitRendering()
+{
+#if TARGET_OS_IPHONE
+    /* iPhone/iPad/aTV needs metal device to render 420 10bit */
+    return cvpx_system_has_metal_device();
+#else
+    /* macOS can render 420 10bit with OpenGL and Metal */
+    return true;
+#endif
+}
+
 static Boolean deviceSupportsAdvancedProfiles()
 {
 #if TARGET_OS_IPHONE

modules/codec/vt_utils.h

@@ -129,6 +129,13 @@ bool cvpx_has_attachment(CVPixelBufferRef pixelBuffer, CFStringRef key);
  */
 void cvpx_attach_mapped_color_properties(CVPixelBufferRef cvpx, 
                                          const video_format_t *fmt);
+/**
+ * @brief Check if current system has at least one metal GPU device
+ * 
+ * @return true if there's at least one metal device available
+ * @return false if there's no metal device
+ */
+bool cvpx_system_has_metal_device();
 
 enum cvpx_video_context_type
 {

modules/codec/vt_utils_native.m

@@ -0,0 +1,14 @@
+#import "vt_utils.h"
+#import <Foundation/Foundation.h>
+#import <Metal/Metal.h>
+
+bool cvpx_system_has_metal_device()
+{
+#if TARGET_OS_IPHONE
+    id<MTLDevice> device = MTLCreateSystemDefaultDevice();
+    return device != nil;
+#else
+    NSArray <id<MTLDevice>> *devices = MTLCopyAllDevices();
+    return devices.count > 0;
+#endif
+}

modules/video_output/Makefile.am

@@ -37,7 +37,7 @@ libglinterop_cvpx_plugin_la_SOURCES = video_output/opengl/interop_cvpx.m \
 	video_output/opengl/interop.h
 libglinterop_cvpx_plugin_la_LIBADD = libvlc_vtutils.la
 libglinterop_cvpx_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(voutdir)' \
-	-Wl,-framework,Foundation,-framework,CoreVideo,-framework,IOSurface
+	-Wl,-framework,Foundation,-framework,CoreVideo,-framework,IOSurface,-framework,Metal
 libglinterop_cvpx_plugin_la_CPPFLAGS = $(AM_CPPFLAGS)
 if HAVE_DARWIN
 if HAVE_OSX
@@ -105,7 +105,7 @@ libcvpx_gl_plugin_la_SOURCES = video_output/apple/VLCCVOpenGLProvider.m
 libcvpx_gl_plugin_la_OBJCFLAGS = $(AM_OBJCFLAGS) -fobjc-arc
 libcvpx_gl_plugin_la_CPPFLAGS = $(AM_CPPFLAGS) -DGL_SILENCE_DEPRECATION
 libcvpx_gl_plugin_la_LDFLAGS = $(AM_LDFLAGS) \
-    -Wl,-framework,Foundation,-framework,CoreFoundation,-framework,CoreVideo
+    -Wl,-framework,Foundation,-framework,CoreFoundation,-framework,CoreVideo,-framework,Metal
 libcvpx_gl_plugin_la_LIBADD = libvlc_vtutils.la
 
 if HAVE_DARWIN