I found out that entries[i].id does not always have videoId in it and sometimes it also contains channelId instead of videoId. So, in this case, we are getting undefined vdoUrl. Can you please check this. I have included a screenshot of the error.
![screenshot](https://f.cloud.github.com/assets/3049313/1606872/63521d98-5460-11e3-811b-acb1650e52d0.png)