From 038ec8b21afddfe6495626b8ab57d8635ab5a811 Mon Sep 17 00:00:00 2001
From: Tianxiao Wang <xiaoyuhen1994@gmail.com>
Date: Mon, 15 Apr 2019 18:10:42 +0800
Subject: [PATCH] fix: cannot read property hdlr of undefined (#66)

---
 packages/griffith-mp4/src/mp4/mp4Box.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/packages/griffith-mp4/src/mp4/mp4Box.js b/packages/griffith-mp4/src/mp4/mp4Box.js
index bafe9ad7..f2f2482f 100644
--- a/packages/griffith-mp4/src/mp4/mp4Box.js
+++ b/packages/griffith-mp4/src/mp4/mp4Box.js
@@ -59,7 +59,7 @@ export default class MP4Box {
       Box.readType(stream)
       Box.readBody(stream)
 
-      if (Box.type === 'trak') {
+      if (Box.type === 'trak' && Box.box.mdia) {
         const handlerType = Box.box.mdia.hdlr.handlerType
         if (handlerType === 'vide') {
           this.box.videoTrak = Box.box