hybridgroup.gobot/examples/tello_opencv.go

95 lines
2.0 KiB
Go

// +build example
//
// Do not build by default.
/*
You must have ffmpeg and OpenCV installed in order to run this code. It will connect to the Tello
and then open a window using OpenCV showing the streaming video.
How to run
go run examples/tello_opencv.go
*/
package main
import (
"fmt"
"io"
"os/exec"
"strconv"
"time"
"gobot.io/x/gobot"
"gobot.io/x/gobot/platforms/dji/tello"
"gocv.io/x/gocv"
)
const (
frameX = 960
frameY = 720
frameSize = frameX * frameY * 3
)
func main() {
drone := tello.NewDriver("8890")
window := gocv.NewWindow("Tello")
ffmpeg := exec.Command("ffmpeg", "-hwaccel", "auto", "-hwaccel_device", "opencl", "-i", "pipe:0",
"-pix_fmt", "bgr24", "-s", strconv.Itoa(frameX)+"x"+strconv.Itoa(frameY), "-f", "rawvideo", "pipe:1")
ffmpegIn, _ := ffmpeg.StdinPipe()
ffmpegOut, _ := ffmpeg.StdoutPipe()
work := func() {
if err := ffmpeg.Start(); err != nil {
fmt.Println(err)
return
}
drone.On(tello.ConnectedEvent, func(data interface{}) {
fmt.Println("Connected")
drone.StartVideo()
drone.SetVideoEncoderRate(tello.VideoBitRateAuto)
drone.SetExposure(0)
gobot.Every(100*time.Millisecond, func() {
drone.StartVideo()
})
})
drone.On(tello.VideoFrameEvent, func(data interface{}) {
pkt := data.([]byte)
if _, err := ffmpegIn.Write(pkt); err != nil {
fmt.Println(err)
}
})
}
robot := gobot.NewRobot("tello",
[]gobot.Connection{},
[]gobot.Device{drone},
work,
)
// calling Start(false) lets the Start routine return immediately without an additional blocking goroutine
robot.Start(false)
// now handle video frames from ffmpeg stream in main thread, to be macOS/Windows friendly
for {
buf := make([]byte, frameSize)
if _, err := io.ReadFull(ffmpegOut, buf); err != nil {
fmt.Println(err)
continue
}
img, _ := gocv.NewMatFromBytes(frameY, frameX, gocv.MatTypeCV8UC3, buf)
if img.Empty() {
continue
}
window.IMShow(img)
if window.WaitKey(1) >= 0 {
break
}
}
}