Go + FFmpeg: How to Find the Duration of Audio and Video

audio_duration.go

func Duration(ctx context.Context, filename string) (time.Duration, error) {
	ctx, cancel := context.WithCancel(ctx)
	defer cancel()
	cmd := exec.CommandContext(ctx, "ffprobe", "-i", filename, "-show_format", "-output_format", "json")
	stdout, err := cmd.StdoutPipe()
	if err != nil {
		return time.Duration(0), nil
	}
	if err := cmd.Start(); err != nil {
		return time.Duration(0), nil
	}
	var output struct {
		Format struct {
			Duration string `json:"duration"`
		} `json:"format"`
	}
	if err := json.NewDecoder(stdout).Decode(&output); err != nil {
		return time.Duration(0), nil
	}
	if err := cmd.Wait(); err != nil {
		return time.Duration(0), nil
	}
	return time.ParseDuration(output.Format.Duration + "s")
}