Adds delegate to enable GPU acceleration in MPPVisionTask

mediapipe/tasks/ios/core/sources/MPPBaseOptions.h

@@ -16,6 +16,11 @@
 
 NS_ASSUME_NONNULL_BEGIN
 
+typedef NS_ENUM(NSInteger, MPPBaseOptionsDelegate) {
+    MPPBaseOptionsDelegateCPU = 0,
+    MPPBaseOptionsDelegateGPU = 1
+} NS_SWIFT_NAME(BaseOptionsDelegate);
+
 /**
  * Holds the base options that is used for creation of any type of task. It has fields with
  * important information acceleration configuration, TFLite model source etc.
@@ -26,6 +31,12 @@ NS_SWIFT_NAME(BaseOptions)
 /** The path to the model asset to open and mmap in memory. */
 @property(nonatomic, copy) NSString *modelAssetPath;
 
+/**
+ * The delegate to run MediaPipe. If the delegate is not set, the default
+ * delegate CPU is used. Use `delegate_options` to configure advanced
+ * features of the selected delegate.
+ */
+@property(nonatomic) MPPBaseOptionsDelegate delegate;
 @end
 
 NS_ASSUME_NONNULL_END

mediapipe/tasks/ios/core/sources/MPPBaseOptions.m

@@ -28,7 +28,7 @@
   MPPBaseOptions *baseOptions = [[MPPBaseOptions alloc] init];
 
   baseOptions.modelAssetPath = self.modelAssetPath;
-
+  baseOptions.delegate = self.delegate;
   return baseOptions;
 }
 

mediapipe/tasks/ios/core/utils/sources/MPPBaseOptions+Helpers.mm

@@ -33,6 +33,16 @@ using BaseOptionsProto = ::mediapipe::tasks::core::proto::BaseOptions;
   if (self.modelAssetPath) {
     baseOptionsProto->mutable_model_asset()->set_file_name(self.modelAssetPath.UTF8String);
   }
+  switch (self.delegate) {
+    case MPPBaseOptionsDelegateCPU: {
+      baseOptionsProto->mutable_acceleration()->mutable_tflite();
+      break;
+    }
+    case MPPBaseOptionsDelegateGPU: {
+      baseOptionsProto->mutable_acceleration()->mutable_gpu();
+      break;
+    }
+  }
 }
 
 @end

mediapipe/tasks/ios/vision/core/sources/MPPImage.m

@@ -98,6 +98,8 @@ NS_ASSUME_NONNULL_BEGIN
   if (imageBuffer == NULL) {
     return nil;
   }
+  _pixelBuffer = imageBuffer;
+  CVPixelBufferRetain(imageBuffer);
 
   self = [super init];
   if (self != nil) {

mediapipe/tasks/ios/vision/core/sources/MPPVisionPacketCreator.mm

@@ -32,6 +32,10 @@ using ::mediapipe::Timestamp;
 @implementation MPPVisionPacketCreator
 
 + (Packet)createPacketWithMPPImage:(MPPImage *)image error:(NSError **)error {
+  if ((image.imageSourceType == MPPImageSourceTypePixelBuffer || image.imageSourceType == MPPImageSourceTypeSampleBuffer) && [image pixelBuffer] != nil) {
+      return MakePacket<mediapipe::Image>([image pixelBuffer]);
+  }
+
   std::unique_ptr<ImageFrame> imageFrame = [image imageFrameWithError:error];
 
   if (!imageFrame) {
@@ -44,14 +48,9 @@ using ::mediapipe::Timestamp;
 + (Packet)createPacketWithMPPImage:(MPPImage *)image
            timestampInMilliseconds:(NSInteger)timestampInMilliseconds
                              error:(NSError **)error {
-  std::unique_ptr<ImageFrame> imageFrame = [image imageFrameWithError:error];
+  auto packet = [self createPacketWithMPPImage:image error:error];
 
-  if (!imageFrame) {
+  return packet.At(Timestamp(int64(timestampInMilliseconds * kMicroSecondsPerMilliSecond)));
-    return Packet();
-  }
-
-  return MakePacket<Image>(std::move(imageFrame))
-      .At(Timestamp(int64(timestampInMilliseconds * kMicroSecondsPerMilliSecond)));
 }
 
 + (Packet)createPacketWithNormalizedRect:(NormalizedRect &)normalizedRect {