龙芯派安装go-opencv

• 其实龙芯派2代已经集成了opencv2 但其实没有安装完全，我们无法正常使用，所以在使用前我们要将其安装完整

yum  install  numpy  opencv* #在龙芯派联网的情况下执行这条命令即可，这样opencv2 就可以安装完成了，就可以正常使用opencv2了

• 要对go的一些环境变量进行修改

export CGO_CFLAGS="-I/usr/include/opencv" 
export CGO_LDFLAGS="-L/usr/lib64 -lopencv_calib3d -lopencv_contrib -lopencv_core -lopencv_features2d -lopencv_flann -lopencv_highgui -lopencv_imgproc -lopencv_legacy -lopencv_ml -lopencv_objdetect -lopencv_photo -lopencv_stitching -lopencv_superres -lopencv_ts -lopencv_video -lopencv_videosta -lpthread"

• 如果还是不行按照接下来的配置来配置go的环境变量

  CGO_ENABLED=1\
  GOOS=linux\
  GOARCH=mips64le\ 
  CC=mips-linux-gnu-gcc\ 
  CXX=mips-linux-gnu-g++\ 
  CGO_CFLAGS="-I/usr/include/opencv"\ 
  CGO_LDFLAGS="-L/usr/lib64 -lopencv_calib3d -lopencv_contrib -lopencv_core -lopencv_features2d -lopencv_flann -lopencv_highgui -lopencv_imgproc -lopencv_legacy -lopencv_ml -lopencv_objdetect -lopencv_photo -lopencv_stitching -lopencv_superres -lopencv_ts -lopencv_video -lopencv_videosta"\ CGO_LDFLAGS="-static"\ 

在这里提一句我们使用的go的opencv库是go-opencv而不是gocv我们这个库使用的是opencv2

库地址 ：https://github.com/go-opencv/go-opencv

• 在这里我给出一个使用opencv2在龙芯派上使用go视频推流的小例子

  package main
  
  import "C"
  import (
      "fmt"
      "github.com/go-opencv/go-opencv/opencv"
      "log"
      "net/http"
      _ "net/http/pprof"
      "unsafe"
  
      //"github.com/gwuhaolin/livego"
      "github.com/hybridgroup/mjpeg"
  )
  
  var (
      deviceID int
      err      error
  
      stream *mjpeg.Stream
      Cap    *opencv.Capture
  )
  
  
  func main() {
  
      // parse args
      //deviceID := 0
      host := ":8554"
  
      // open webcam
  
      Cap = opencv.NewCameraCapture(0)
      //Cap = opencv.NewFileCapture("/home/zjh/test.flv")
      fmt.Println("1")
      if Cap == nil {
          panic("can not open camera")
          return
      }
      defer Cap.Release()
      
      // create the mjpeg stream
      stream = mjpeg.NewStream()
      
      // start capturing
      
      go mjpegCapture()
      
      fmt.Println("Capturing. Point your browser to " + host)
  
      // start http server
      http.Handle("/", stream)
      
      log.Fatal(http.ListenAndServe(host, nil))
  }
  
  func mjpegCapture() {
  
      for {
          
          img := Cap.RetrieveFrame(1)
      
  
          if img != nil {
              
              buf := opencv.EncodeImage(".jpg", unsafe.Pointer(img.GetMat()), []int{64})
  
              bufss := buf.GetData()
              fmt.Println("9")
              stream.UpdateJPEG(bufss)
              fmt.Println("10")
          } else if img == nil {
              fmt.Println("Image is nil")
              break
          }
      }
  
  }
  

• 要想跑起来这个程序还是不行，因为swig库支持的版本太低了，我们要去swig的官网，下载源码后在龙芯派上进行交叉编译

• 然后执行

  export CGO_LDFLAGS="-g -O2 -lm"
  go run main.go

  即可编译成功