I almost gave up on Dtube. But alas, it's working and I'm excited about it, now.
I tried uploading a video a few different times, but the video upload failed every time. It also seems that I wasn't the only one having problems. Different people had different problems, as you can see here, and here. There are a lot of people asking about slightly different issues for the past month or so, but the end result was the same.
They couldn't upload. Neither could I.
The behavior I was experiencing was that I would start uploading the video, --as the video begins uploading, it starts playing automatically-- this is a bit strange, but I figured it was part of the system. It also would show the bitrate of the video at 10.1. But after a long time, sometimes over an hour, the video just wouldn't finish uploading.
I looked everywhere for a solution. I watched the video by @Terrybrock interviewing the developer of Dtube, 
They mentioned that the service prefers mp4 with h.264 format. I was using this so I knew that wasn't the problem. In a way, I'm glad that there isn't a lot of technical specs outlined for Dtube because this will encourage people to just use it without having to worry too much about the geeky stuff like bitrate, etc.
But I went back to my video editing software to double-check all the settings. I was definitely using the right settings, but I noticed that Final Cut Pro exports into "m4v" rather than mp4. The extension of m4v is just a slight variation of mp4 but the encoding is still done in h.264. It should work, I thought. I re-exported it anyway and decided to try again.
These are the settings I used for Final Cut Pro.
I used the export to Master File option, then the following settings as shown in the screenshot.
As I was listening to the interview, then I went to watch other videos on Dtube to keep me busy. A watched pot never boils, right? So I was hoping that the upload would just eventually work.
Eventually, I looked over to my open upload tab and voila! The upload video upload box had a green check mark! Finally and for the first time.
I had tried this at least 4 times before and for whatever reason, it didn't work until now. I hope it was just an unlucky streak of glitches and it will continue to work well in the future.
But of course, it's beta!
I know Dtube is beta, and I am thankful and grateful that
They covered this in the interview, currently, it is impossible to edit parts of the video like the description, title, and I think even tags. From a technical point of view, I think I understand it because of how the video is hosted and delivered. But from a creative standpoint, it's just not going to fly with most creators.
Jokingly,
Sometimes the circumstances behind a video change and it is required that the description gets updated. At the very least and without much thought, I can think of a few scenarios; new information, inaccurate information, follow-up video links or resources and others.
The other thing that I hope to see soon is an upload progress bar or indicator. I understand if the video isn't ready for consumption for 10 - 30 minutes after it has been uploaded, but the ability to know how much of a video has been uploaded, I think it is critical to get mass adoption.
Overall, I think this is a good platform. It needs major work and improvements but it's already better than a few other alternative platforms I have tried. If you're having a hard time uploading, check your settings, read a few of the other people's posts and the threads and give it another try.
Oh yeah, and if you want to see the first video I uploaded to Dtube, this is it: