Fix iOS forward bug

Prj-iOS/hyperlpr3/hyperlpr3.xcodeproj/project.pbxproj

@@ -679,10 +679,15 @@
 					"$(inherited)",
 					"$(PROJECT_DIR)",
 				);
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"INFERENCE_HELPER_ENABLE_MNN=1",
+					"IOS_CPU_FORWARD=1",
+				);
 				GENERATE_INFOPLIST_FILE = YES;
 				HEADER_SEARCH_PATHS = "$(SRCROOT)/../../cpp/src";
 				INFOPLIST_KEY_NSHumanReadableCopyright = "";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",
@@ -713,10 +718,15 @@
 					"$(inherited)",
 					"$(PROJECT_DIR)",
 				);
+				GCC_PREPROCESSOR_DEFINITIONS = (
+					"INFERENCE_HELPER_ENABLE_MNN=1",
+					"IOS_CPU_FORWARD=1",
+				);
 				GENERATE_INFOPLIST_FILE = YES;
 				HEADER_SEARCH_PATHS = "$(SRCROOT)/../../cpp/src";
 				INFOPLIST_KEY_NSHumanReadableCopyright = "";
 				INSTALL_PATH = "$(LOCAL_LIBRARY_DIR)/Frameworks";
+				IPHONEOS_DEPLOYMENT_TARGET = 12.0;
 				LD_RUNPATH_SEARCH_PATHS = (
 					"$(inherited)",
 					"@executable_path/Frameworks",

cpp/src/buffer_module/camera_buffer.cpp

@@ -43,9 +43,9 @@ void CameraBuffer::SetDataFormat(DATA_FORMAT data_format) {
     if (data_format == BGRA) {
         config_.sourceFormat = MNN::CV::BGRA;
     }
-    if (data_format == YCrCb) {
-        config_.sourceFormat = MNN::CV::YCrCb;
-    }
+//    if (data_format == YCrCb) {
+//        config_.sourceFormat = MNN::CV::YCrCb;
+//    }
 }
 
 cv::Mat CameraBuffer::GetAffineRGBImage(const cv::Mat &affine_matrix, const int width_out, const int height_out) const {

cpp/src/inference_helper_module/inference_helper_mnn.cpp

@@ -176,7 +176,12 @@ int32_t InferenceHelperMnn::Initialize(const std::string& model_filename, std::v
     }
 
     MNN::ScheduleConfig scheduleConfig;
+#ifdef IOS_CPU_FORWARD
+    PRINT("ios use cpu backend.");
+    scheduleConfig.type = MNN_FORWARD_CPU;
+#else
     scheduleConfig.type = MNN_FORWARD_AUTO;
+#endif
     scheduleConfig.numThread = num_threads_;    // it seems, setting 1 has better performance on Android
     // MNN::BackendConfig bnconfig;
     // bnconfig.power = MNN::BackendConfig::Power_High;