diff --git a/fileinfo.go b/fileinfo.go
index 757e463..c144c87 100644
--- a/fileinfo.go
+++ b/fileinfo.go
@@ -1,10 +1,12 @@
 package main
 
 import (
-	"log"
+	"fmt"
+	"io/ioutil"
 	"os"
+	"strings"
 
-	"github.com/rakyll/magicmime"
+	filetype "gopkg.in/h2non/filetype.v1"
 )
 
 func getFileSize(s string) (size int64, err error) {
@@ -22,17 +24,72 @@ func getFileSize(s string) (size int64, err error) {
 	return
 }
 
-func getFileMime(s string) (mimetype string, err error) {
-	if err := magicmime.Open(magicmime.MAGIC_MIME_TYPE | magicmime.MAGIC_SYMLINK | magicmime.MAGIC_ERROR); err != nil {
-		log.Fatal(err)
-		return "", err
+// not able to detect audio/amr and requries linux local dependency, not good
+// func getFileMime(s string) (mimetype string, err error) {
+// 	if err := magicmime.Open(magicmime.MAGIC_MIME_TYPE | magicmime.MAGIC_SYMLINK | magicmime.MAGIC_ERROR); err != nil {
+// 		log.Fatal(err)
+// 		return "", err
+// 	}
+// 	defer magicmime.Close()
+
+// 	mimetype, err = magicmime.TypeByFile(s)
+// 	if err != nil {
+// 		log.Fatalf("error occured during type lookup: %v", err)
+// 	}
+// 	//log.Printf("mime-type: %v", mimetype)
+// 	return
+// }
+
+func getFileMime(s string) (mimetype string, ext string, err error) {
+	buf, _ := ioutil.ReadFile(s)
+
+	kind, unkwown := filetype.Match(buf)
+	if unkwown != nil {
+		fmt.Printf("Unkwown: %s", unkwown)
+		return
 	}
-	defer magicmime.Close()
+	mimetype = kind.MIME.Value
+	ext = kind.Extension
+	//fmt.Printf("File type: %s. MIME: %s\n", kind.Extension, kind.MIME.Value)
+	return
+}
 
-	mimetype, err = magicmime.TypeByFile(s)
+func isMP3(path string) bool {
+	mime, ext, err := getFileMime(path)
 	if err != nil {
-		log.Fatalf("error occured during type lookup: %v", err)
+		return false
 	}
-	//log.Printf("mime-type: %v", mimetype)
-	return
+	check1 := strings.EqualFold("mp3", ext)
+	check2 := strings.EqualFold("audio/mpeg", mime)
+	return check1 && check2
+}
+
+func isAmr(path string) bool {
+	mime, ext, err := getFileMime(path)
+	if err != nil {
+		return false
+	}
+	check1 := strings.EqualFold("amr", ext)
+	check2 := strings.EqualFold("audio/amr", mime)
+	return check1 && check2
+}
+
+func isMP4(path string) bool {
+	mime, ext, err := getFileMime(path)
+	if err != nil {
+		return false
+	}
+	check1 := strings.EqualFold("mp4", ext)
+	check2 := strings.EqualFold("video/mp4", mime)
+	return check1 && check2
+}
+
+func isJPG(path string) bool {
+	mime, ext, err := getFileMime(path)
+	if err != nil {
+		return false
+	}
+	check1 := strings.EqualFold("jpg", ext)
+	check2 := strings.EqualFold("image/jpeg", mime)
+	return check1 && check2
 }
diff --git a/fileinfo_test.go b/fileinfo_test.go
index f6fb02b..4196afa 100644
--- a/fileinfo_test.go
+++ b/fileinfo_test.go
@@ -8,12 +8,14 @@ import (
 func TestGetFileSize(t *testing.T) {
 
 	var fileSize = map[string]int{
-		"media_for_test/640x480.jpg":   50668,
-		"media_for_test/3640x3480.jpg": 785190,
-		"media_for_test/video.mp4":     75520,
+		"640x480.jpg":             50668,
+		"3640x3480.jpg":           785190,
+		"video.mp4":               75520,
+		"example.amr":             56486,
+		"wechat_incoming_msg.mp3": 14639,
 	}
 	for k, v := range fileSize {
-		size, _ := getFileSize(k)
+		size, _ := getFileSize("media_for_test/" + k)
 		msg := fmt.Sprintf("%s should have size %d, not %d", k, v, size)
 		AssertEqual(t, size, int64(v), msg)
 	}
@@ -21,13 +23,75 @@ func TestGetFileSize(t *testing.T) {
 
 func TestGetMimeType(t *testing.T) {
 	var fileMime = map[string]string{
-		"media_for_test/640x480.jpg":   "image/jpeg",
-		"media_for_test/3640x3480.jpg": "image/jpeg",
-		"media_for_test/video.mp4":     "video/mp4",
+		"640x480.jpg":             "image/jpeg",
+		"3640x3480.jpg":           "image/jpeg",
+		"video.mp4":               "video/mp4",
+		"example.amr":             "audio/amr",
+		"wechat_incoming_msg.mp3": "audio/mpeg",
 	}
 	for k, v := range fileMime {
-		mime, _ := getFileMime(k)
+		mime, _, _ := getFileMime("media_for_test/" + k)
 		msg := fmt.Sprintf("%s should be %s, not %s", k, v, mime)
 		AssertEqual(t, mime, v, msg)
 	}
 }
+
+func TestIsMP3(t *testing.T) {
+	var mp3 = map[string]bool{
+		"640x480.jpg":             false,
+		"3640x3480.jpg":           false,
+		"video.mp4":               false,
+		"example.amr":             false,
+		"wechat_incoming_msg.mp3": true,
+	}
+	for k, v := range mp3 {
+		r := isMP3("media_for_test/" + k)
+		msg := fmt.Sprintf("%s is mp3 = %t, not %t", k, v, r)
+		AssertEqual(t, v, r, msg)
+	}
+}
+
+func TestIsAMR(t *testing.T) {
+	var amr = map[string]bool{
+		"640x480.jpg":             false,
+		"3640x3480.jpg":           false,
+		"video.mp4":               false,
+		"example.amr":             true,
+		"wechat_incoming_msg.mp3": false,
+	}
+	for k, v := range amr {
+		r := isAmr("media_for_test/" + k)
+		msg := fmt.Sprintf("%s AMR = %t, not %t", k, v, r)
+		AssertEqual(t, v, r, msg)
+	}
+}
+
+func TestIsMP4(t *testing.T) {
+	var mp4 = map[string]bool{
+		"640x480.jpg":             false,
+		"3640x3480.jpg":           false,
+		"video.mp4":               true,
+		"example.amr":             false,
+		"wechat_incoming_msg.mp3": false,
+	}
+	for k, v := range mp4 {
+		r := isMP4("media_for_test/" + k)
+		msg := fmt.Sprintf("%s MP4 = %t, not %t", k, v, r)
+		AssertEqual(t, v, r, msg)
+	}
+}
+
+func TestIsJPG(t *testing.T) {
+	var mp4 = map[string]bool{
+		"640x480.jpg":             true,
+		"3640x3480.jpg":           true,
+		"video.mp4":               false,
+		"example.amr":             false,
+		"wechat_incoming_msg.mp3": false,
+	}
+	for k, v := range mp4 {
+		r := isJPG("media_for_test/" + k)
+		msg := fmt.Sprintf("%s JPG = %t, not %t", k, v, r)
+		AssertEqual(t, v, r, msg)
+	}
+}
diff --git a/media_for_test/example.amr b/media_for_test/example.amr
new file mode 100644
index 0000000..4c5a213
Binary files /dev/null and b/media_for_test/example.amr differ
diff --git a/media_for_test/wechat_incoming_msg.mp3 b/media_for_test/wechat_incoming_msg.mp3
new file mode 100644
index 0000000..9e9f432
Binary files /dev/null and b/media_for_test/wechat_incoming_msg.mp3 differ