func (s *CIService) GetSnapshot(ctx context.Context, name string, opt *GetSnapshotOptions, id ...string) (*Response, error)

opt := &cos.GetSnapshotOptions{
    Time: 1,
} 
resp, err := c.CI.GetSnapshot(context.Background(), "test.mp4", opt)
if err != nil {
    // ERROR
}

fd, err := os.OpenFile("test.jpg", os.O_WRONLY|os.O_CREATE|os.O_TRUNC, 0660)
if err != nil {
    // ERROR
} 
_, err = io.Copy(fd, resp.Body)
fd.Close()

type GetSnapshotOptions struct {
    Time   float32 
    Height int 
    Width  int  
    Format string
    Rotate string
    Mode   string
}