First, let me say "thanks" for such an awesome product. I found pitivi about 2 months ago and it has been a lifesaver. I typically produce desktop captures using openoffice presentation, recorded by gtk desktop recorder on my ubuntu box.
Pitivi allows me to then convert that presentation into flv and present it online along with a mp3 and pdf (from the oo presentation) for downloading. Pitivi is a key part of that working.
And Pitivi typically works very well. I have found some occasions when it doesn't.
I'm not here to just complain, and I know I could easily just go issue some bugs, but sometimes the bug reporting misses some of the interaction that can happen here on the mailing list. And bug tracking isn't usually monitored by other users that would be on this list, and they could (hopefully) contribute to the discussion. At any point you guys (maintainers of pitivi) want something issued as a bug, let me know and I'll be happy to do it. That being said, on to some issues.
I have two laptops. One is a 2.5GHz dual-core w/ 4G ram. It's running Ubuntu 9.10 and only auto-installs Pitivi 0.13.3. The other laptop is a single-core 1.6GHz w/ 1.5G ram. It's running Ubuntu 10.4 and auto-installs the newer version of Pitivi (not handy or I'd tell you the exact version number).
Since the older laptop has the newer pitivi, I usually do all my work on it. That means working with a project and the rendering is all slower. I'm not complaining (esp about the rendering part, not much you can do to speed it up), but I think one adjustment could help on the compilation part: have a Edit->Preferences where you can turn off the "preview frames" in video and audio. When you work with any stream that is larger than the current timeline window, and you slide in one direction or the other I have to wait literally 30 seconds to a full minute before I can start working with the new location in the timeline. And typically when I drop a new vid into the timeline I just let the machine crunch until it's "preview framed" the entire thing before trying to do something with it. Another frustration that would be solved is when you zoom in on the time line, you have to wait for the preview frames to "catch up", making working with small increments of the video very impractical, especially when you have to find the exact split second you want to start a transition and you are scanning over a 30-second segment. The preview in the timeline *doesn't help you do this*, it just gets in the way. The best way to find that "split second" is by clicking the timeline and looking at the player screen to see exactly when the frame(s) change.
Instead of displaying the framed-preview, if selected as "off", it should just display the first frame repeatedly or the title of that stream repeatedly. Maybe when a source is added to the clips list it can be rt-clicked and selected to "not preview the framed-preview" so that a person can select which clips are important to be previewed in the timeline and which ones aren't. To build on that idea, a stream can be rt-clicked in the timeline and selected to preview or not preview in the timeline.
Another thing on the frame-preview in the timeline - while pitivi is actually rendering the project the timeline preview should be disabled, as pitivi advances through the frames and the timeline advances, it eats up cpu trying to build the newly viewed timeline segment's frame-previews. Why does it need to do that? It's just taking cpu away from the important process - the render.
All-in-all, pitivi works great for videos that are 20 min or so. I've found that large video projects have problems. My feature recommendation is one that I think can make or break pitivi emerging as a "large project" tool. All just suggestions to help with compiling a long vid on a slower machine.
The second issue I'd like to discuss is actually a bug. I have this one video that is 1:50 long (that's one hour and 50 minutes). The first 30 minutes I needed to overlay the video with still-shots. That worked just fine (except it takes about 2 hours to position the stills correctly because the timeline frame-preview issue discussed above). The render takes well over 24 hours (again, I can live with that, I'm on an older laptop), but when it's done the video and the audio don't match up.
Here's a (ugly) representation of how the timeline looks (with about 20 still shots, I jut use 3 to give you the rough idea):
The video and audio match up just find all the way through the part where I overlaid the still shots, but once the "normal" video starts, the video is accelerated and the audio is at normal speed.
I even tried splitting the original vid/audio stream up, cut off the part of the video that is overlaid by the still shots, etc... No matter what combo I tried, when the original video started up, the video would play much faster than the audio.
The second problem I've encountered was on this same project. After working for 2 hours to get all the stills lined up, the "render" button would be disabled. Sometimes the "render" button would be enabled, but when I'd click on it the small dialog that tells the container format and the vid/audio formats would be "empty" - it would just have no entries in either of those formats. I couldn't get it to allow me to make any changes, and the "cancel" button would be disabled. I'd have to click the "x" to close the dialog. Even after closing pitivi all the way down, the process would still be running, I'd have to issue a kill from the command line to actually get pitivi to exit. When I'd save and re-open the project the render button would still be disabled. And yes, the video and still-shots did start at the first frame in the timeline. Correspondingly, when I couldn't render I also couldn't play the preview player... It was disabled as well.
And I'd always wait until the frame-previewing was "caught up" (the cpu would idle back down) so I know it wasn't busy trying to do that when the render dialog would "act up".
Imagine slaving away for 2 hours to get everything lined up, just to have to throw it all away and try again. And then when you finally get the render button after the 3rd or 4th attempt at building the project you wait 24 hours just to find out the video is accelerated after the still-shot frames are finished.
I slaved over this project for over a week, rendering it several times, rebuilding the entire thing many many times. I never got a final video I could use. I ended up having to use command line mencoder.
This experience was a pitivi-killer in my book. I'll continue to use it for smaller videos but I can't trust it for large videos.
I'd be happy to bundle up the project files and clips and send them along to anyone who would want to try to diagnose the problem.
And of course, if you guys want a bug or two created, I'd be more than happy to do that too.
I look forward to your discussion!