Saving a continuous stream of images from ffmpeg image2pipe - go

Question

I am trying to save a sequence/continuous images from ffmpeg image2pipe in go. The problem with the code below that it does only save the first image in the stream due to the blocking nature of io.Copy since it waits for the reader or the writer to close.
package main
import (
"fmt"
"io"
"log"
"os"
"os/exec"
"strconv"
"time"
)
//Trying to get png from stdout pipe
func main() {
fmt.Println("Running the camera stream")
ffmpegCmd := exec.Command("ffmpeg", "-loglevel", "quiet", "-y", "-rtsp_transport", "tcp", "-i", "rtsp://admin:123456#192.168.1.41:554/h264Preview_01_main", "-r", "1", "-f", "image2pipe", "pipe:1")
ffmpegOut, err := ffmpegCmd.StdoutPipe()
if err != nil {
return
}
err = ffmpegCmd.Start()
if err != nil {
log.Fatal(err)
}
count := 0
for {
count++
t := time.Now()
fmt.Println("writing image" + strconv.Itoa(count))
filepath := "image-" + strconv.Itoa(count) + "-" + t.Format("20060102150405.png")
out, err := os.Create(filepath)
if err != nil {
log.Fatal(err)
}
defer out.Close()
_, err = io.Copy(out, ffmpegOut)
if err != nil {
log.Fatalf("unable to copy to file: %s", err.Error())
}
}
if err := ffmpegCmd.Wait(); err != nil {
log.Fatal("Error while waiting:", err)
}
}
I implemented my own save and copy function based on the io.Copy code https://golang.org/src/io/io.go
func copyAndSave(w io.Writer, r io.Reader) error {
buf := make([]byte, 1024, 1024)
for {
n, err := r.Read(buf[:])
if n == 0 {
}
if n > 0 {
d := buf[:n]
_, err := w.Write(d)
if err != nil {
return err
}
}
if err != nil {
return err
}
}
return nil
}
then I updated the for loop in my main function to the below block but still I am only getting the first image in the sequence. due to r.Read(buf[:]) is being a blocking call.
for {
count++
t := time.Now()
fmt.Println("writing image" + strconv.Itoa(count))
filepath := "image-" + strconv.Itoa(count) + "-" + t.Format("20060102150405.png")
out, err := os.Create(filepath)
if err != nil {
log.Fatal(err)
}
defer out.Close()
err = copyAndSave(out, ffmpegOut)
if err != nil {
if err == io.EOF {
break
}
log.Fatalf("unable to copy to file: %s", err.Error())
break
}
}