feat: implement ImageVectorPacket (#1020)

Packages/com.github.homuler.mediapipe/Runtime/Scripts/Framework/Packet/ImageVectorPacket.cs

@@ -0,0 +1,74 @@
+// Copyright (c) 2023 homuler
+//
+// Use of this source code is governed by an MIT-style
+// license that can be found in the LICENSE file or at
+// https://opensource.org/licenses/MIT.
+
+using System;
+using System.Collections.Generic;
+using System.Runtime.InteropServices;
+
+namespace Mediapipe
+{
+  public class ImageVectorPacket : Packet<List<Image>>
+  {
+    [StructLayout(LayoutKind.Sequential)]
+    internal readonly struct ImageVector
+    {
+      private readonly IntPtr _data;
+      private readonly int _size;
+
+      public void Dispose()
+      {
+        UnsafeNativeMethods.mp_api_ImageArray__delete(_data);
+      }
+
+      public List<Image> Copy()
+      {
+        var images = new List<Image>(_size);
+
+        unsafe
+        {
+          var imagePtr = (IntPtr*)_data;
+
+          for (var i = 0; i < _size; i++)
+          {
+            var image = new Image(*imagePtr++, true);
+            images.Add(image);
+          }
+        }
+
+        return images;
+      }
+    }
+
+    /// <summary>
+    ///   Creates an empty <see cref="ImageVectorPacket" /> instance.
+    /// </summary>
+    public ImageVectorPacket() : base(true) { }
+
+    [UnityEngine.Scripting.Preserve]
+    public ImageVectorPacket(IntPtr ptr, bool isOwner = true) : base(ptr, isOwner) { }
+
+    public ImageVectorPacket At(Timestamp timestamp)
+    {
+      return At<ImageVectorPacket>(timestamp);
+    }
+
+    public override List<Image> Get()
+    {
+      UnsafeNativeMethods.mp_Packet__GetImageVector(mpPtr, out var imageVector).Assert();
+      GC.KeepAlive(this);
+
+      var images = imageVector.Copy();
+      imageVector.Dispose();
+
+      return images;
+    }
+
+    public override List<Image> Consume()
+    {
+      throw new NotSupportedException();
+    }
+  }
+}

Packages/com.github.homuler.mediapipe/Runtime/Scripts/PInvoke/NativeMethods/Framework/Format/Image_Unsafe.cs

@@ -54,8 +54,14 @@ internal static partial class UnsafeNativeMethods
     [DllImport(MediaPipeLibrary, ExactSpelling = true)]
     public static extern MpReturnCode mp_Packet__GetImage(IntPtr packet, out IntPtr image);
 
+    [DllImport(MediaPipeLibrary, ExactSpelling = true)]
+    public static extern MpReturnCode mp_Packet__GetImageVector(IntPtr packet, out ImageVectorPacket.ImageVector imageVector);
+
     [DllImport(MediaPipeLibrary, ExactSpelling = true)]
     public static extern MpReturnCode mp_Packet__ValidateAsImage(IntPtr packet, out IntPtr status);
+
+    [DllImport(MediaPipeLibrary, ExactSpelling = true)]
+    public static extern MpReturnCode mp_api_ImageArray__delete(IntPtr array);
     #endregion
   }
 }

mediapipe_api/framework/formats/image.cc

@@ -119,9 +119,28 @@ MpReturnCode mp_Packet__GetImage(mediapipe::Packet* packet, const mediapipe::Ima
   return mp_Packet__Get(packet, value_out);
 }
 
+MpReturnCode mp_Packet__GetImageVector(mediapipe::Packet* packet, mp_api::StructArray<mediapipe::Image*>* value_out) {
+  TRY_ALL
+    auto vec = packet->Get<std::vector<mediapipe::Image>>();
+    auto size = vec.size();
+    auto data = new mediapipe::Image*[size];
+
+    for (auto i = 0; i < size; ++i) {
+      data[i] = new mediapipe::Image(std::move(vec[i]));
+    }
+    value_out->data = data;
+    value_out->size = static_cast<int>(size);
+    RETURN_CODE(MpReturnCode::Success);
+  CATCH_ALL
+}
+
 MpReturnCode mp_Packet__ValidateAsImage(mediapipe::Packet* packet, absl::Status** status_out) {
   TRY
     *status_out = new absl::Status{packet->ValidateAsType<mediapipe::Image>()};
     RETURN_CODE(MpReturnCode::Success);
   CATCH_EXCEPTION
 }
+
+void mp_api_ImageArray__delete(mediapipe::Image** image_array) {
+  delete[] image_array;
+}

mediapipe_api/framework/formats/image.h

@@ -63,8 +63,11 @@ MP_CAPI(MpReturnCode) mp__MakeImagePacket__Pif(mediapipe::Image* image, mediapip
 MP_CAPI(MpReturnCode) mp__MakeImagePacket_At__Pif_Rt(mediapipe::Image* image, mediapipe::Timestamp* timestamp, mediapipe::Packet** packet_out);
 MP_CAPI(MpReturnCode) mp_Packet__ConsumeImage(mediapipe::Packet* packet, absl::Status **status_out, mediapipe::Image** value_out);
 MP_CAPI(MpReturnCode) mp_Packet__GetImage(mediapipe::Packet* packet, const mediapipe::Image** value_out);
+MP_CAPI(MpReturnCode) mp_Packet__GetImageVector(mediapipe::Packet* packet, mp_api::StructArray<mediapipe::Image*>* value_out);
 MP_CAPI(MpReturnCode) mp_Packet__ValidateAsImage(mediapipe::Packet* packet, absl::Status** status_out);
 
+MP_CAPI(void) mp_api_ImageArray__delete(mediapipe::Image** image_array);
+
 }  // extern "C"
 
 #endif  // MEDIAPIPE_API_FRAMEWORK_FORMATS_IMAGE_H_