portable version of mmap

DarknetImage move float conversion into c code

.gitignore

@@ -1,9 +1,14 @@
-example/main
-example/coco.names
-example/yolov3.cfg
-example/yolov3.weights
-example/yolov4.cfg
-example/yolov4.weights
+cmd/examples/main
+cmd/examples/base_example/main
+cmd/examples/coco.names
+cmd/examples/yolov3.cfg
+cmd/examples/yolov3.weights
+cmd/examples/yolov4.cfg
+cmd/examples/yolov4.weights
+cmd/examples/yolov4-tiny.cfg
+cmd/examples/yolov4-tiny.weights
+cmd/examples/yolov7-tiny.cfg
+cmd/examples/yolov7-tiny.weights
 darknet.h
 *.so
 predictions.png

Makefile

@@ -1,8 +1,9 @@
 .ONESHELL:
-.PHONY: prepare_cuda prepare_cudnn download_darknet build_darknet build_darknet_gpu clean clean_cuda clean_cudnn
+.PHONY: prepare_cuda prepare_cudnn download_darknet build_darknet build_darknet_gpu clean clean_cuda clean_cudnn sudo_install
 
 # Latest battletested AlexeyAB version of Darknet commit
-LATEST_COMMIT?=f056fc3b6a11528fa0522a468eca1e909b7004b7
+# LATEST_COMMIT?=f056fc3b6a11528fa0522a468eca1e909b7004b7
+LATEST_COMMIT?=9d40b619756be9521bc2ccd81808f502daaa3e9a
 
 # Temporary folder for building Darknet
 TMP_DIR?=/tmp/

README.md

@@ -3,12 +3,13 @@
 [![Go Report Card](https://goreportcard.com/badge/github.com/LdDl/go-darknet)](https://goreportcard.com/report/github.com/LdDl/go-darknet)
 [![GitHub tag](https://img.shields.io/github/tag/LdDl/go-darknet.svg)](https://github.com/LdDl/go-darknet/releases)
 
-# go-darknet: Go bindings for Darknet (Yolo V4, Yolo V3)
-### go-darknet is a Go package, which uses Cgo to enable Go applications to use YOLO V4/V3 in [Darknet].
+# go-darknet: Go bindings for Darknet (Yolo V4, Yolo V7-tiny, Yolo V3)
+### go-darknet is a Go package, which uses Cgo to enable Go applications to use V4/V7-tiny/V3 in [Darknet].
 
 #### Since this repository https://github.com/gyonluks/go-darknet  is no longer maintained I decided to move on and make little different bindings for Darknet.
 #### This bindings aren't for [official implementation](https://github.com/pjreddie/darknet) but for [AlexeyAB's fork](https://github.com/AlexeyAB/darknet).
 
+#### Paper Yolo v7: https://arxiv.org/abs/2207.02696 (WARNING: Only 'tiny' variation works currently)
 #### Paper Yolo v4: https://arxiv.org/abs/2004.10934
 #### Paper Yolo v3: https://arxiv.org/abs/1804.02767
 
@@ -26,7 +27,7 @@
 
 Because this repository https://github.com/gyonluks/go-darknet is no longer maintained.
 
-**What is purpose of this bindings when you can have [GoCV](https://github.com/hybridgroup/gocv#gocv) (bindings to OpenCV) and it handle Darnet YOLO perfectly?**
+**What is purpose of this bindings when you can have [GoCV](https://github.com/hybridgroup/gocv#gocv) (bindings to OpenCV) and it handle Darknet YOLO perfectly?**
 
 Well, you don't need bunch of OpenCV dependencies and OpenCV itself sometimes.
 
@@ -35,7 +36,7 @@ Example of such project here: https://github.com/LdDl/license_plate_recognition#
 
 ## Requirements
 
-You need to install fork of [darknet](https://github.com/AlexeyAB/darknet). Latest commit I've tested is [here](https://github.com/AlexeyAB/darknet/commit/d65909fbea471d06e52a2e4a41132380dc2edaa6)
+You need to install fork of [darknet](https://github.com/AlexeyAB/darknet). Latest commit I've tested is [here](https://github.com/AlexeyAB/darknet/commit/9d40b619756be9521bc2ccd81808f502daaa3e9a). It corresponds last official [YOLOv4 release](https://github.com/AlexeyAB/darknet/releases/tag/yolov4)
 
 Use provided [Makefile](Makefile).
 
@@ -64,19 +65,23 @@ go get github.com/LdDl/go-darknet
 
 ## Usage
 
-Example Go program is provided in the [example] directory. Please refer to the code on how to use this Go package.
+Example Go program is provided in the [examples] directory. Please refer to the code on how to use this Go package.
 
 Building and running program:
 
-* Navigate to [example] folder
+* Navigate to [examples] folder
     ```shell
-    cd $GOPATH/github.com/LdDl/go-darknet/example/base_example
+    cd ${YOUR PATH}/github.com/LdDl/go-darknet/cmd/examples
     ```
 
 * Download dataset (sample of image, coco.names, yolov4.cfg (or v3), yolov4.weights(or v3)).
     ```shell
     #for yolo v4
     ./download_data.sh
+    #for yolo v4 tiny
+    ./download_data_v4_tiny.sh
+    #for yolo v7 tiny
+    ./download_data_v7_tiny.sh
     #for yolo v3
     ./download_data_v3.sh
     ```
@@ -106,29 +111,71 @@ Building and running program:
     It will reduce amount of VRAM used for detector test.
 
 
-* Build and run program
-    Yolo V4:
+* Build and run example program
+    
+    Yolo v7 tiny:
     ```shell
-    go build main.go && ./main --configFile=yolov4.cfg --weightsFile=yolov4.weights --imageFile=sample.jpg
+    go build -o base_example/main base_example/main.go && ./base_example/main --configFile=yolov7-tiny.cfg --weightsFile=yolov7-tiny.weights --imageFile=sample.jpg
     ```
 
     Output should be something like this:
     ```shell
-    traffic light (9): 73.5039% | start point: (238,73) | end point: (251, 106)
+    truck (7): 53.2890% | start point: (0,143) | end point: (89, 328)
+    truck (7): 42.1364% | start point: (685,182) | end point: (800, 318)
+    truck (7): 26.9703% | start point: (437,170) | end point: (560, 217)
+    car (2): 87.7818% | start point: (509,189) | end point: (742, 329)
+    car (2): 87.5633% | start point: (262,191) | end point: (423, 322)
+    car (2): 85.4743% | start point: (427,198) | end point: (549, 309)
+    car (2): 71.3772% | start point: (0,147) | end point: (87, 327)
+    car (2): 62.5698% | start point: (98,151) | end point: (197, 286)
+    car (2): 61.5811% | start point: (693,186) | end point: (799, 316)
+    car (2): 49.6343% | start point: (386,206) | end point: (441, 286)
+    car (2): 28.2012% | start point: (386,205) | end point: (440, 236)
+    bicycle (1): 71.9609% | start point: (179,294) | end point: (249, 405)
+    person (0): 85.4390% | start point: (146,130) | end point: (269, 351)
+    ```
+
+    Yolo v4:
+    ```shell
+    go build -o base_example/main base_example/main.go && ./base_example/main --configFile=yolov4.cfg --weightsFile=yolov4.weights --imageFile=sample.jpg
+    ```
+
+    Output should be something like this:
+    ```shell
+    traffic light (9): 73.5040% | start point: (238,73) | end point: (251, 106)
     truck (7): 96.6401% | start point: (95,79) | end point: (233, 287)
     truck (7): 96.4774% | start point: (662,158) | end point: (800, 321)
     truck (7): 96.1841% | start point: (0,77) | end point: (86, 333)
-    truck (7): 46.8695% | start point: (434,173) | end point: (559, 216)
+    truck (7): 46.8694% | start point: (434,173) | end point: (559, 216)
     car (2): 99.7370% | start point: (512,188) | end point: (741, 329)
-    car (2): 99.2533% | start point: (260,191) | end point: (422, 322)
+    car (2): 99.2532% | start point: (260,191) | end point: (422, 322)
     car (2): 99.0333% | start point: (425,201) | end point: (547, 309)
-    car (2): 83.3919% | start point: (386,210) | end point: (437, 287)
+    car (2): 83.3920% | start point: (386,210) | end point: (437, 287)
     car (2): 75.8621% | start point: (73,199) | end point: (102, 274)
     car (2): 39.1925% | start point: (386,206) | end point: (442, 240)
     bicycle (1): 76.3121% | start point: (189,298) | end point: (253, 402)
     person (0): 97.7213% | start point: (141,129) | end point: (283, 362)
     ```
 
+    Yolo v4 tiny:
+    ```shell
+    go build -o base_example/main base_example/main.go && ./base_example/main --configFile=yolov4-tiny.cfg --weightsFile=yolov4-tiny.weights --imageFile=sample.jpg
+    ```
+
+    Output should be something like this:
+    ```shell
+    truck (7): 77.7936% | start point: (0,138) | end point: (90, 332)
+    truck (7): 55.9773% | start point: (696,174) | end point: (799, 314)
+    car (2): 53.1286% | start point: (696,184) | end point: (799, 319)
+    car (2): 98.0222% | start point: (262,189) | end point: (424, 330)
+    car (2): 97.8773% | start point: (430,190) | end point: (542, 313)
+    car (2): 81.4099% | start point: (510,190) | end point: (743, 325)
+    car (2): 43.3935% | start point: (391,207) | end point: (435, 299)
+    car (2): 37.4221% | start point: (386,206) | end point: (429, 239)
+    car (2): 32.0724% | start point: (109,196) | end point: (157, 289)
+    person (0): 73.0868% | start point: (154,132) | end point: (284, 382)
+    ```
+
     Yolo V3:
     ```
     go build main.go && ./main --configFile=yolov3.cfg --weightsFile=yolov3.weights --imageFile=sample.jpg
@@ -136,19 +183,19 @@ Building and running program:
 
     Output should be something like this:
     ```shell
-    truck (7): 49.5197% | start point: (0,136) | end point: (85, 311)
-    car (2): 36.3747% | start point: (95,152) | end point: (186, 283)
-    truck (7): 48.4384% | start point: (95,152) | end point: (186, 283)
-    truck (7): 45.6590% | start point: (694,178) | end point: (798, 310)
-    car (2): 76.8379% | start point: (1,145) | end point: (84, 324)
-    truck (7): 25.5731% | start point: (107,89) | end point: (215, 263)
-    car (2): 99.8783% | start point: (511,185) | end point: (748, 328)
-    car (2): 99.8194% | start point: (261,189) | end point: (427, 322)
-    car (2): 99.6408% | start point: (426,197) | end point: (539, 311)
-    car (2): 74.5610% | start point: (692,186) | end point: (796, 316)
-    car (2): 72.8053% | start point: (388,206) | end point: (437, 276)
-    bicycle (1): 72.2932% | start point: (178,270) | end point: (268, 406)
-    person (0): 97.3026% | start point: (143,135) | end point: (268, 343)
+    truck (7): 49.5123% | start point: (0,136) | end point: (85, 311)
+    car (2): 36.3694% | start point: (95,152) | end point: (186, 283)
+    truck (7): 48.4177% | start point: (95,152) | end point: (186, 283)
+    truck (7): 45.6520% | start point: (694,178) | end point: (798, 310)
+    car (2): 76.8402% | start point: (1,145) | end point: (84, 324)
+    truck (7): 25.5920% | start point: (107,89) | end point: (215, 263)
+    car (2): 99.8782% | start point: (511,185) | end point: (748, 328)
+    car (2): 99.8193% | start point: (261,189) | end point: (427, 322)
+    car (2): 99.6405% | start point: (426,197) | end point: (539, 311)
+    car (2): 74.5627% | start point: (692,186) | end point: (796, 316)
+    car (2): 72.7975% | start point: (388,206) | end point: (437, 276)
+    bicycle (1): 72.2760% | start point: (178,270) | end point: (268, 406)
+    person (0): 97.3007% | start point: (143,135) | end point: (268, 343)
     ```
 
 ## Documentation
@@ -165,5 +212,5 @@ go-darknet follows [Darknet]'s [license].
 [darknet.h]: https://github.com/AlexeyAB/darknet/blob/master/include/darknet.h
 [include/darknet.h]: https://github.com/AlexeyAB/darknet/blob/master/include/darknet.h
 [Makefile]: https://github.com/alexeyab/darknet/blob/master/Makefile
-[example]: /example/base_example
+[examples]: cmd/examples/base_example
 [GoDoc]: https://godoc.org/github.com/LdDl/go-darknet

cmd/examples/base_example/main.go

@@ -9,7 +9,9 @@ import (
 	"log"
 	"math"
 	"os"
+
 	darknet "github.com/LdDl/go-darknet"
+
 	"github.com/disintegration/imaging"
 )
 

cmd/examples/download_data_v4_tiny.sh

@@ -0,0 +1,5 @@
+wget --output-document=sample.jpg https://cdn-images-1.medium.com/max/800/1*EYFejGUjvjPcc4PZTwoufw.jpeg
+wget --output-document=coco.names https://raw.githubusercontent.com/AlexeyAB/darknet/master/data/coco.names
+wget --output-document=yolov4-tiny.cfg https://raw.githubusercontent.com/AlexeyAB/darknet/master/cfg/yolov4-tiny.cfg
+sed -i -e "\$anames = coco.names" yolov4-tiny.cfg
+wget --output-document=yolov4-tiny.weights https://github.com/AlexeyAB/darknet/releases/download/yolov4/yolov4-tiny.weights

cmd/examples/download_data_v7_tiny.sh

@@ -0,0 +1,5 @@
+wget --output-document=sample.jpg https://cdn-images-1.medium.com/max/800/1*EYFejGUjvjPcc4PZTwoufw.jpeg
+wget --output-document=coco.names https://raw.githubusercontent.com/AlexeyAB/darknet/master/data/coco.names
+wget --output-document=yolov7-tiny.cfg https://raw.githubusercontent.com/AlexeyAB/darknet/master/cfg/yolov7-tiny.cfg
+sed -i -e "\$anames = coco.names" yolov7-tiny.cfg
+wget --output-document=yolov7-tiny.weights https://github.com/AlexeyAB/darknet/releases/download/yolov4/yolov7-tiny.weights

cmd/examples/rest_example/main.go

@@ -11,7 +11,7 @@ import (
 	"log"
 	"net/http"
 
-	"github.com/LdDl/go-darknet"
+	darknet "github.com/LdDl/go-darknet"
 )
 
 var configFile = flag.String("configFile", "",

go.mod

@@ -0,0 +1,14 @@
+module github.com/LdDl/go-darknet
+
+go 1.17
+
+require (
+	github.com/disintegration/imaging v1.6.2
+	github.com/pkg/errors v0.9.1
+	golang.org/x/image v0.0.0-20211028202545-6944b10bf410
+)
+
+require (
+	github.com/edsrzf/mmap-go v1.1.0 // indirect
+	golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e // indirect
+)

go.sum

@@ -0,0 +1,14 @@
+github.com/disintegration/imaging v1.6.2 h1:w1LecBlG2Lnp8B3jk5zSuNqd7b4DXhcjwek1ei82L+c=
+github.com/disintegration/imaging v1.6.2/go.mod h1:44/5580QXChDfwIclfc/PCwrr44amcmDAg8hxG0Ewe4=
+github.com/edsrzf/mmap-go v1.1.0 h1:6EUwBLQ/Mcr1EYLE4Tn1VdW1A4ckqCQWZBw8Hr0kjpQ=
+github.com/edsrzf/mmap-go v1.1.0/go.mod h1:19H/e8pUPLicwkyNgOykDXkJ9F0MHE+Z52B8EIth78Q=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+golang.org/x/image v0.0.0-20191009234506-e7c1f5e7dbb8/go.mod h1:FeLwcggjj3mMvU+oOTbSwawSJRM1uh48EjtB4UJZlP0=
+golang.org/x/image v0.0.0-20211028202545-6944b10bf410 h1:hTftEOvwiOq2+O8k2D5/Q7COC7k5Qcrgc2TFURJYnvQ=
+golang.org/x/image v0.0.0-20211028202545-6944b10bf410/go.mod h1:023OzeP/+EPmXeapQh35lcL3II3LrY8Ic+EFFKVhULM=
+golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e h1:fLOSk5Q00efkSvAm+4xcoXD+RRmLmmulPn5I3Y9F2EM=
+golang.org/x/sys v0.0.0-20211216021012-1d35b9e2eb4e/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
+golang.org/x/text v0.3.6/go.mod h1:5Zoc/QRtKVWzQhOtBMvqHzDpF6irO9z98xDceosuGiQ=
+golang.org/x/tools v0.0.0-20180917221912-90fa682c2a6e/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

image.c

@@ -11,3 +11,18 @@ void set_data_f32_val(float* data, int index, float value) {
     data[index] = value;
 }
 
+void to_float_and_fill_image(image* im, int w, int h, uint8_t* data) {
+    int x, y, idx_source;
+    int pixel_count = w * h;
+    int idx = 0;
+
+    for (y = 0; y < h; y++) {
+        for (x = 0; x < w; x++) {
+            idx_source = (y*w + x) * 4;
+            im->data[(pixel_count*0) + idx] = (float)data[idx_source] / 255;
+            im->data[(pixel_count*1) + idx] = (float)data[idx_source+1] / 255;
+            im->data[(pixel_count*2) + idx] = (float)data[idx_source+2] / 255;
+            idx++;
+        }
+    }
+}

image.go

@@ -14,61 +14,33 @@ import (
 type DarknetImage struct {
 	Width  int
 	Height int
-	ans    []float32
 	image  C.image
 }
 
 // Close and release resources.
 func (img *DarknetImage) Close() error {
 	C.free_image(img.image)
-	img.ans = nil
 	return nil
 }
 
-// https://stackoverflow.com/questions/33186783/get-a-pixel-array-from-from-golang-image-image/59747737#59747737
-func imgTofloat32(src image.Image) []float32 {
+func Image2Float32(src image.Image) (*DarknetImage, error) {
 	bounds := src.Bounds()
-	width, height := bounds.Max.X, bounds.Max.Y
-	srcRGBA := image.NewRGBA(src.Bounds())
-	draw.Copy(srcRGBA, image.Point{}, src, src.Bounds(), draw.Src, nil)
+	srcRGBA := image.NewRGBA(bounds)
+	draw.Copy(srcRGBA, image.Point{}, src, bounds, draw.Src, nil)
 
-	red := make([]float32, 0, width*height)
-	green := make([]float32, 0, width*height)
-	blue := make([]float32, 0, width*height)
-	for y := 0; y < height; y++ {
-		for x := 0; x < width; x++ {
-			idxSource := (y*width + x) * 4
-			pix := srcRGBA.Pix[idxSource : idxSource+4]
-			rpix, gpix, bpix := float32(pix[0])/257.0, float32(pix[1])/257.0, float32(pix[2])/257.0
-			red = append(red, rpix)
-			green = append(green, gpix)
-			blue = append(blue, bpix)
-		}
-	}
-	srcRGBA = nil
-
-	ans := make([]float32, len(red)+len(green)+len(blue))
-	copy(ans[:len(red)], red)
-	copy(ans[len(red):len(red)+len(green)], green)
-	copy(ans[len(red)+len(green):], blue)
-	red = nil
-	green = nil
-	blue = nil
-	return ans
+	return ImageRGBA2Float32(srcRGBA)
 }
 
 // Image2Float32 Returns []float32 representation of image.Image
-func Image2Float32(img image.Image) (*DarknetImage, error) {
-	// ans := imgTofloat32(img)
+func ImageRGBA2Float32(img *image.RGBA) (*DarknetImage, error) {
 	width := img.Bounds().Dx()
 	height := img.Bounds().Dy()
 	imgDarknet := &DarknetImage{
 		Width:  width,
 		Height: height,
-		ans:    imgTofloat32(img),
 		image:  C.make_image(C.int(width), C.int(height), 3),
 	}
-	C.fill_image_f32(&imgDarknet.image, C.int(width), C.int(height), 3, (*C.float)(unsafe.Pointer(&imgDarknet.ans[0])))
+	C.to_float_and_fill_image(&imgDarknet.image, C.int(width), C.int(height), (*C.uint8_t)(unsafe.Pointer(&img.Pix[0])))
 	return imgDarknet, nil
 }
 

image.h

@@ -4,3 +4,4 @@
 
 extern void fill_image_f32(image *im, int w, int h, int c, float* data);
 extern void set_data_f32_val(float* data, int index, float value);
+extern void to_float_and_fill_image(image *im, int w, int h, uint8_t* data);

network.go

@@ -7,9 +7,13 @@ package darknet
 // #include "network.h"
 import "C"
 import (
-	"errors"
+	"io/ioutil"
+	"os"
 	"time"
 	"unsafe"
+
+	"github.com/edsrzf/mmap-go"
+	"github.com/pkg/errors"
 )
 
 // YOLONetwork represents a neural network using YOLO.
@@ -53,6 +57,81 @@ func (n *YOLONetwork) Init() error {
 	return nil
 }
 
+/* EXPERIMENTAL */
+/*
+	By default AlexeyAB's Darknet doesn't export any functions in darknet.h to give ability to create network from scratch via code.
+	So I can't modify `parse_network_cfg_custom` to load `list *sections = read_cfg(filename);` from memory.
+
+	So, the point of this method is to be able create network configuration via Golang and then pass it to `C.load_network`
+
+	This code is portable for Windows/Linux/MacOS. See the ref.: https://github.com/edsrzf/mmap-go#mmap-go
+*/
+func (n *YOLONetwork) InitFromDefinedCfg() error {
+	wFile := C.CString(n.WeightsFile)
+	defer C.free(unsafe.Pointer(wFile))
+	/* Prepare network sections via Go */
+	/*
+		instead of using:
+			wFile := C.CString(n.WeightsFile)
+			defer C.free(unsafe.Pointer(wFile))
+		We call `load_network` that takes the first char* parameter (representing a file path to network configuration) with a Go function that takes an in-memory file
+	*/
+	cfgBytes, err := os.ReadFile(n.NetworkConfigurationFile)
+	if err != nil {
+		return errors.Wrap(err, "Can't read file bytes")
+	}
+
+	// Create a temporary file.
+	tmpFile, err := ioutil.TempFile("", "")
+	if err != nil {
+		return errors.Wrap(err, "Can't create temporary file")
+	}
+	defer os.Remove(tmpFile.Name())
+	// Write the file content to the temporary file.
+	if _, err := tmpFile.Write(cfgBytes); err != nil {
+		return errors.Wrap(err, "Can't write network's configuration into temporary file")
+	}
+	defer tmpFile.Close()
+
+	// Open the temporary file.
+	// fd, err := syscall.Open(tmpFile.Name(), syscall.O_RDWR, 0)
+	// if err != nil {
+	// 	return errors.Wrap(err, "Can't re-open temporary file")
+	// }
+	// defer syscall.Close(fd)
+	// Create a memory mapping of the file.
+	// addr, err := syscall.Mmap(fd, 0, len(cfgBytes), syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_SHARED)
+	// if err != nil {
+	// 	return errors.Wrap(err, "Can't mmap on temporary file")
+	// }
+	// Unmap the memory-mapped file.
+	// defer syscall.Munmap(addr)
+
+	// Map the temporary file to memory.
+	mapping, err := mmap.Map(tmpFile, mmap.RDWR, 0)
+	if err != nil {
+		return errors.Wrap(err, "Can't mmap on temporary file")
+	}
+	defer mapping.Unmap() // Unmap the memory-mapped file.
+
+	// GPU device ID must be set before `load_network()` is invoked.
+	C.cuda_set_device(C.int(n.GPUDeviceIndex))
+	nCfg := C.CString(tmpFile.Name())
+	defer C.free(unsafe.Pointer(nCfg))
+	n.cNet = C.load_network(nCfg, wFile, 0)
+	if n.cNet == nil {
+		return errUnableToInitNetwork
+	}
+	C.srand(2222222)
+	n.hierarchalThreshold = 0.5
+	n.nms = 0.45
+	metadata := C.get_metadata(nCfg)
+	n.Classes = int(metadata.classes)
+	n.ClassNames = makeClassNames(metadata.names, n.Classes)
+
+	return nil
+}
+
 // Close and release resources.
 func (n *YOLONetwork) Close() error {
 	if n.cNet == nil {

section.go

@@ -0,0 +1,58 @@
+package darknet
+
+import (
+	"bufio"
+	"os"
+	"strings"
+)
+
+// Section represents a section in the configuration file.
+type Section struct {
+	Type    string
+	Options []string
+}
+
+// readCfg reads a configuration file and returns a list of sections.
+func readCfg(filename string) ([]Section, error) {
+	// Open the configuration file.
+	file, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer file.Close()
+
+	// Create a list of sections.
+	var sections []Section
+	var current *Section
+
+	// Read each line in the file.
+	scanner := bufio.NewScanner(file)
+	for scanner.Scan() {
+		line := strings.TrimSpace(scanner.Text())
+		if line == "" {
+			continue
+		}
+		switch line[0] {
+		case '[':
+			if current != nil {
+				sections = append(sections, *current)
+			}
+			current = &Section{Type: line}
+		case '#', ';', '\x00':
+			// Ignore comments and empty lines.
+		default:
+			if current == nil {
+				current = &Section{}
+			}
+			current.Options = append(current.Options, line)
+		}
+	}
+	if current != nil {
+		sections = append(sections, *current)
+	}
+	if err := scanner.Err(); err != nil {
+		return nil, err
+	}
+
+	return sections, nil
+}

section_test.go

@@ -0,0 +1,20 @@
+package darknet
+
+import (
+	"fmt"
+	"testing"
+)
+
+func TestReadSectionsFromCfg(t *testing.T) {
+	sections, err := readCfg("./cmd/examples/yolov7-tiny.cfg")
+	if err != nil {
+		fmt.Println(err)
+		return
+	}
+	for _, s := range sections {
+		fmt.Println(s.Type)
+		for _, o := range s.Options {
+			fmt.Println("\t", o)
+		}
+	}
+}