Add experimental CoreML delegate

* Update TensorFlowLiteC to TensorFlowLiteC/Core (version 2.4.0)
* Add TensorFlowLiteC/Metal to restore Metal delegate after v2.4.0 moved
  it to a separate pod.
* Add TensorflowLiteC/CoreML to add experimental CoreML delegate.
* Add documentation of  option.

Signed-off-by: Daniel Llewellyn <[email protected]>

Author: Daniel Llewellyn

README.md

@@ -86,6 +86,7 @@ String res = await Tflite.loadModel(
   numThreads: 1, // defaults to 1
   isAsset: true, // defaults to true, set to false to load resources outside assets
   useGpuDelegate: false // defaults to false, set to true to use GPU delegate
+  useCoreMLDelegate: false // defaults to false, set to true to use CoreML delegate on iOS devices - has no effect on Android
 );
 ```
 

example/ios/Flutter/Debug.xcconfig

@@ -1,2 +1,3 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Pods/Target Support Files/Pods-Runner/Pods-Runner.debug.xcconfig"
 #include "Generated.xcconfig"

example/ios/Flutter/Release.xcconfig

@@ -1,2 +1,3 @@
+#include? "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Pods/Target Support Files/Pods-Runner/Pods-Runner.release.xcconfig"
 #include "Generated.xcconfig"

example/ios/Podfile.lock

@@ -3,9 +3,16 @@ PODS:
   - image_picker (0.0.1):
     - Flutter
   - TensorFlowLiteC (2.2.0)
-  - tflite (1.1.2):
+  - TensorFlowLiteC/Core (2.4.0)
+  - TensorFlowLiteC/CoreML (2.4.0):
+    - TensorFlowLiteC/Core
+  - TensorFlowLiteC/Metal (2.4.0):
+    - TensorFlowLiteC/Core
+  - tflite (1.1.1):
     - Flutter
-    - TensorFlowLiteC
+    - TensorFlowLiteC/Core
+    - TensorFlowLiteC/CoreML
+    - TensorFlowLiteC/Metal
 
 DEPENDENCIES:
   - Flutter (from `Flutter`)
@@ -27,8 +34,8 @@ EXTERNAL SOURCES:
 SPEC CHECKSUMS:
   Flutter: 434fef37c0980e73bb6479ef766c45957d4b510c
   image_picker: a211f28b95a560433c00f5cd3773f4710a20404d
-  TensorFlowLiteC: b3ab9e867b0b71052ca102a32a786555b330b02e
-  tflite: f0403a894740019d63ab5662253bba5b2dd37296
+  TensorFlowLiteC: 09f8ac75a76caeadb19bcfa694e97454cc1ecf87
+  tflite: d701e08676abd255d3340a79bb8cb4ba1594723c
 
 PODFILE CHECKSUM: 8e679eca47255a8ca8067c4c67aab20e64cb974d
 

example/ios/Runner.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

ios/Classes/TflitePlugin.mm

@@ -19,6 +19,7 @@
 #elif defined TFLITE2
 #import "TensorFlowLiteC.h"
 #import "metal_delegate.h"
+#import "coreml_delegate.h"
 #else
 #include "tensorflow/lite/kernels/register.h"
 #include "tensorflow/lite/model.h"
@@ -118,6 +119,7 @@ - (void)handleMethodCall:(FlutterMethodCall*)call result:(FlutterResult)result {
 TfLiteInterpreter *interpreter = nullptr;
 TfLiteModel *model = nullptr;
 TfLiteDelegate *delegate = nullptr;
+bool isCoreMLDelegate = false;
 #else
 std::unique_ptr<tflite::FlatBufferModel> model;
 std::unique_ptr<tflite::Interpreter> interpreter;
@@ -160,10 +162,19 @@ static void LoadLabels(NSString* labels_path,
   }
   options = TfLiteInterpreterOptionsCreate();
   TfLiteInterpreterOptionsSetNumThreads(options, num_threads);
-  
+
   bool useGpuDelegate = [args[@"useGpuDelegate"] boolValue];
-  if (useGpuDelegate) {
+  bool useCoreMLDelegate = [args[@"useCoreMLDelegate"] boolValue];
+  if (useCoreMLDelegate) {
+    delegate = TfLiteCoreMlDelegateCreate(nullptr);
+    if (delegate != NULL) {
+      isCoreMLDelegate = true;
+    }
+  }
+  if (delegate == NULL && useGpuDelegate) {
     delegate = TFLGpuDelegateCreate(nullptr);
+  }
+  if (delegate != NULL) {
     TfLiteInterpreterOptionsAddDelegate(options, delegate);
   }
 #else
@@ -1488,8 +1499,11 @@ void runPoseNetOnFrame(NSDictionary* args, FlutterResult result) {
 void close() {
 #ifdef TFLITE2
   interpreter = nullptr;
-  if (delegate != nullptr)
+  if (isCoreMLDelegate && delegate != nullptr) {
+    TfLiteCoreMlDelegateDelete(delegate);
+  } else if (delegate != nullptr) {
     TFLGpuDelegateDelete(delegate);
+  }
   delegate = nullptr;
 #else
   interpreter.release();

ios/tflite.podspec

@@ -15,8 +15,10 @@ A Flutter plugin for accessing TensorFlow Lite. Supports both iOS and Android.
   s.source_files = 'Classes/**/*'
   s.public_header_files = 'Classes/**/*.h'
   s.dependency 'Flutter'
-  s.dependency 'TensorFlowLiteC'
-  s.xcconfig = { 'USER_HEADER_SEARCH_PATHS' => '$(inherited) "${PODS_ROOT}/Headers/Private" "${PODS_ROOT}/Headers/Private/tflite" "${PODS_ROOT}/Headers/Public" "${PODS_ROOT}/Headers/Public/Flutter" "${PODS_ROOT}/Headers/Public/TensorFlowLite/tensorflow_lite" "${PODS_ROOT}/Headers/Public/tflite" "${PODS_ROOT}/TensorFlowLite/Frameworks/tensorflow_lite.framework/Headers" "${PODS_ROOT}/TensorFlowLiteC/Frameworks/TensorFlowLiteC.framework/Headers"' }
+  s.dependency 'TensorFlowLiteC/Core'
+  s.dependency 'TensorFlowLiteC/Metal'
+  s.dependency 'TensorFlowLiteC/CoreML'
+  s.xcconfig = { 'USER_HEADER_SEARCH_PATHS' => '$(inherited) "${PODS_ROOT}/Headers/Private" "${PODS_ROOT}/Headers/Private/tflite" "${PODS_ROOT}/Headers/Public" "${PODS_ROOT}/Headers/Public/Flutter" "${PODS_ROOT}/Headers/Public/TensorFlowLite/tensorflow_lite" "${PODS_ROOT}/Headers/Public/tflite" "${PODS_ROOT}/TensorFlowLite/Frameworks/tensorflow_lite.framework/Headers" "${PODS_ROOT}/TensorFlowLiteC/Frameworks/TensorFlowLiteC.framework/Headers" "${PODS_ROOT}/TensorFlowLiteC/Frameworks/TensorFlowLiteCMetal.framework/Headers" "${PODS_ROOT}/TensorFlowLiteC/Frameworks/TensorFlowLiteCCoreML.framework/Headers"' }
 
   s.ios.deployment_target = '9.0'
   s.static_framework = true

lib/tflite.dart

@@ -11,15 +11,17 @@ class Tflite {
       String labels = "",
       int numThreads = 1,
       bool isAsset = true,
-      bool useGpuDelegate = false}) async {
+      bool useGpuDelegate = false,
+      bool useCoreMLDelegate = false}) async {
     return await _channel.invokeMethod(
       'loadModel',
       {
         "model": model,
         "labels": labels,
         "numThreads": numThreads,
         "isAsset": isAsset,
-        'useGpuDelegate': useGpuDelegate
+        "useGpuDelegate": useGpuDelegate,
+        "useCoreMLDelegate": useCoreMLDelegate
       },
     );
   }