I've recently upgraded 11.10 to 12.04 and then reinstalled Pitivi and Gstreamer codecs ecxept the extra codecs and regardless of which container,vid codec or aud codec the rendering bar wouldn't move any help would be helpful, and if your wondering if it used to work in 11.10 it only work in the first few tries before it also stopped rendering.
P.S: I'm still a nooby.
The version 0.15.1 installed via the repository has this problem, but do these steps will solve (by compiling 0.15.2):
Open a terminal (Ctrl + Alt + T) and enter these commands (after each line typed below press "Enter"):
My problem with pitivi was that it did not show any progress in the render dialog and just kept raising the 'estimated time' to finish rendering.
After the guys on #pitivi asked me what container/codecs I used, I switched the video codec from "Dirac" to "Theora" and I could render my video. I had the Ogg container, Theora for video, and Vorbis for audio.
I'm not sure right now what version of pitivi comes with 12.04, but I did install 0.15.2 from the sources at the end. Maybe you did the same (installing 0.15.2) but didn't try some other video codec instead of Dirac?
This bug was reported on 2011-12-10
Bug 665902 - Render never completes because of a not-linked element
See : https://bugzilla.gnome.org/show_bug.cgi?id=665902
I found this thread several years later trying to render a video in Ubuntu 16.04 using Pitivi 0.95
I found that I was unable to render to mp4 format, but was able to use other formats. avi worked best for me. I realize this is not an acceptable solution for everyone, but if you absolutely need mp4 perhaps you can find some other means to convert to mp4.
Use flatpak. Thanks to running the app into a container, it's almost impossible you get an error to run the latest version. The latest version is much faster and more stable. There setup instruction is here.
I would recommend you completely remove Pitivi and reinstall through the terminal:
That should remove Pitivi and reinstall it :) Now if that doesn't help, I suggest you try a new editor. Pitivi has been known to have it's issues, that's why it was removed as a default application in Ubuntu. My favoured video editor is Open shot, available in the Ubuntu Software Center. There are however users who remote stability issues. It is powerful, versatile and fun to use. Most importantly the developers are actively improving it: http://www.openshotvideo.com/
There is also Kdenlive, often hailed as the best free video editor on Linux. http://www.kdenlive.org/