Using FFprobe for video metadata

utils.go

@@ -0,0 +1,82 @@
+package main
+
+import (
+	"errors"
+	"os"
+	"os/exec"
+	"strconv"
+	"strings"
+)
+
+// Returns true if file exists, false otherwise.
+// https://stackoverflow.com/questions/12518876/how-to-check-if-a-file-exists-in-go
+func Exists(filename string) bool {
+	_, err := os.Stat(filename)
+	if err == nil {
+		return true
+	}
+	if errors.Is(err, os.ErrNotExist) {
+		return false
+	}
+	return false
+}
+
+// Checks if the given program is installed.
+func CheckExists(program string) {
+	cmd := exec.Command(program, "-version")
+	if err := cmd.Start(); err != nil {
+		panic(program + " is not installed.")
+	}
+	if err := cmd.Wait(); err != nil {
+		panic(program + " is not installed.")
+	}
+}
+
+// Parse ffprobe output to fill in video data.
+func parseFFprobe(input []byte, video *Video) {
+	data := make(map[string]string)
+	for _, line := range strings.Split(string(input), "|") {
+		if strings.Contains(line, "=") {
+			keyValue := strings.Split(line, "=")
+			if _, ok := data[keyValue[0]]; !ok {
+				data[keyValue[0]] = keyValue[1]
+			}
+		}
+	}
+
+	video.width = int(parse(data["width"]))
+	video.height = int(parse(data["height"]))
+	video.duration = float64(parse(data["duration"]))
+	video.frames = int(parse(data["nb_frames"]))
+
+	split := strings.Split(data["r_frame_rate"], "/")
+	if len(split) == 2 && split[0] != "" && split[1] != "" {
+		video.fps = parse(split[0]) / parse(split[1])
+	}
+
+	video.bitrate = int(parse(data["bit_rate"]))
+	video.codec = data["codec_name"]
+	video.pix_fmt = data["pix_fmt"]
+}
+
+func parse(data string) float64 {
+	n, err := strconv.ParseFloat(data, 64)
+	if err != nil {
+		return 0
+	}
+	return n
+}
+
+// func main() {
+// 	os := runtime.GOOS
+// 	switch os {
+// 	case "windows":
+// 		fmt.Println("Windows")
+// 	case "darwin":
+// 		fmt.Println("MAC operating system")
+// 	case "linux":
+// 		fmt.Println("Linux")
+// 	default:
+// 		fmt.Printf("%s.\n", os)
+// 	}
+// }