From ea9ed60a33d69ef9169b9220299f29e2c993bd4d Mon Sep 17 00:00:00 2001
From: "Kin-Yiu, Wong" <kinyiu@iis.sinica.edu.tw>
Date: Thu, 7 Mar 2024 11:42:05 +0800
Subject: [PATCH] Update experimental.py

https://github.com/WongKinYiu/yolov9/pull/189
---
 models/experimental.py | 103 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 103 insertions(+)

diff --git a/models/experimental.py b/models/experimental.py
index ae087c5..80ee2e0 100644
--- a/models/experimental.py
+++ b/models/experimental.py
@@ -66,6 +66,109 @@ def forward(self, x, augment=False, profile=False, visualize=False):
         return y, None  # inference, train output
 
 
+class TRT_NMS(torch.autograd.Function):
+    '''TensorRT NMS operation'''
+    @staticmethod
+    def forward(
+        ctx,
+        boxes,
+        scores,
+        background_class=-1,
+        box_coding=1,
+        iou_threshold=0.45,
+        max_output_boxes=100,
+        plugin_version="1",
+        score_activation=0,
+        score_threshold=0.25,
+    ):
+
+        batch_size, num_boxes, num_classes = scores.shape
+        num_det = torch.randint(0, max_output_boxes, (batch_size, 1), dtype=torch.int32)
+        det_boxes = torch.randn(batch_size, max_output_boxes, 4)
+        det_scores = torch.randn(batch_size, max_output_boxes)
+        det_classes = torch.randint(0, num_classes, (batch_size, max_output_boxes), dtype=torch.int32)
+        return num_det, det_boxes, det_scores, det_classes
+
+    @staticmethod
+    def symbolic(g,
+                 boxes,
+                 scores,
+                 background_class=-1,
+                 box_coding=1,
+                 iou_threshold=0.45,
+                 max_output_boxes=100,
+                 plugin_version="1",
+                 score_activation=0,
+                 score_threshold=0.25):
+        out = g.op("TRT::EfficientNMS_TRT",
+                   boxes,
+                   scores,
+                   background_class_i=background_class,
+                   box_coding_i=box_coding,
+                   iou_threshold_f=iou_threshold,
+                   max_output_boxes_i=max_output_boxes,
+                   plugin_version_s=plugin_version,
+                   score_activation_i=score_activation,
+                   score_threshold_f=score_threshold,
+                   outputs=4)
+        nums, boxes, scores, classes = out
+        return nums, boxes, scores, classes
+
+
+
+class ONNX_TRT(nn.Module):
+    '''onnx module with TensorRT NMS operation.'''
+    def __init__(self, max_obj=100, iou_thres=0.45, score_thres=0.25, max_wh=None ,device=None, n_classes=80):
+        super().__init__()
+        assert max_wh is None
+        self.device = device if device else torch.device('cpu')
+        self.background_class = -1,
+        self.box_coding = 1,
+        self.iou_threshold = iou_thres
+        self.max_obj = max_obj
+        self.plugin_version = '1'
+        self.score_activation = 0
+        self.score_threshold = score_thres
+        self.n_classes=n_classes
+
+    def forward(self, x):
+        ## https://github.com/thaitc-hust/yolov9-tensorrt/blob/main/torch2onnx.py
+        ## thanks https://github.com/thaitc-hust
+        if isinstance(x, list):  ## yolov9-c.pt and yolov9-e.pt return list
+            x = x[1]
+        x = x.permute(0, 2, 1)
+        bboxes_x = x[..., 0:1]
+        bboxes_y = x[..., 1:2]
+        bboxes_w = x[..., 2:3]
+        bboxes_h = x[..., 3:4]
+        bboxes = torch.cat([bboxes_x, bboxes_y, bboxes_w, bboxes_h], dim = -1)
+        bboxes = bboxes.unsqueeze(2) # [n_batch, n_bboxes, 4] -> [n_batch, n_bboxes, 1, 4]
+        obj_conf = x[..., 4:]
+        scores = obj_conf
+        num_det, det_boxes, det_scores, det_classes = TRT_NMS.apply(bboxes, scores, self.background_class, self.box_coding,
+                                                                    self.iou_threshold, self.max_obj,
+                                                                    self.plugin_version, self.score_activation,
+                                                                    self.score_threshold)
+        return num_det, det_boxes, det_scores, det_classes
+
+class End2End(nn.Module):
+    '''export onnx or tensorrt model with NMS operation.'''
+    def __init__(self, model, max_obj=100, iou_thres=0.45, score_thres=0.25, max_wh=None, device=None, n_classes=80):
+        super().__init__()
+        device = device if device else torch.device('cpu')
+        assert isinstance(max_wh,(int)) or max_wh is None
+        self.model = model.to(device)
+        self.model.model[-1].end2end = True
+        self.patch_model = ONNX_TRT 
+        self.end2end = self.patch_model(max_obj, iou_thres, score_thres, max_wh, device, n_classes)
+        self.end2end.eval()
+
+    def forward(self, x):
+        x = self.model(x)
+        x = self.end2end(x)
+        return x
+
+
 def attempt_load(weights, device=None, inplace=True, fuse=True):
     # Loads an ensemble of models weights=[a,b,c] or a single model weights=[a] or weights=a
     from models.yolo import Detect, Model