PiTiVi has problems to switch from one video track to another when they follow each other

[zsolt.ruszinyák]

Binary package hint: pitivi

When I load multiple videos and static images into the project area, this is the behaviour I'm getting:

When a video track reaches it's end or when the other one begins, the view gets stuck at this point, for a couple of seconds. The problem is present when more videos follow each other in one project, or when a video is followed by a static image. Switching from a static image to another static image goes fluently.

Of course, this might be because of my weak hardware. On the other hand, I can even play a video during the rendering and neither the video, nor the rendering gets jerky, so probably my hardware is catching up, nonetheless. The problem will probably be in PiTiVi, which gets overloaded.

Check my screencast

ProblemType: Bug
DistroRelease: Ubuntu 10.04
Package: pitivi 0.13.4-0ubuntu3
ProcVersionSignature: Ubuntu 2.6.32-24.38-generic 2.6.32.15+drm33.5
Uname: Linux 2.6.32-24-generic i686
Architecture: i386
Date: Thu Jul 22 21:10:34 2010
ExecutablePath: /usr/bin/pitivi
InstallationMedia: Ubuntu 10.04 LTS "Lucid Lynx" - Release i386 (20100429)
InterpreterPath: /usr/bin/python2.6
PackageArchitecture: all
ProcEnviron:
 LANG=en_GB.utf8
 SHELL=/bin/bash
SourcePackage: pitivi

[Jeff Fortin Tam (kiddo)]

Hi, please provide your hardware specs (the CPU type/speed, the amount of RAM, and your GPU/video card,...)
Then provide information on the video clips you are using (codec, resolution) and the project resolution settings.

If it renders fine, then it's quite possibly your hardware being unable to keep up with live playback in pitivi. Know, however, that there are some known performance problems (see http://wiki.pitivi.org/wiki/Performance_problems_in_0.13.4 ). Work is ongoing to solve these performance issues.

[zsolt.ruszinyák (zsolt-ruszinyak)]

I have an EeePC → Intel Atom 1,6, Intel GMA945 (128 shared), 1GB RAM.

My next try was successful, I saved the project and restarted PiTiVi. And whoala, it was quite fluent. I think you just need to get lucky, sometimes it does it, sometimes not.

[zsolt.ruszinyák (zsolt-ruszinyak)]

But to be correct, the video and the static image didn't overlap each other, they came one after the another, I even tried with a gap. That's why I think it's not a hardware deficiency but the program, Cause PiTiVi has certain problems to finish the video track in certain situations: Bug #608968.

Project settings: 640x312, 24 fps, the static image had 720x720, container: avi, audio codec: AAC, video codec: XviD. Everything with the default settings.

[zsolt.ruszinyák (zsolt-ruszinyak)]

Oh yeah, and the original video clip was .flv (quite a bad format)...

[randolf (wolle321)]

Hello I have this problem too.
My hardware is an Core2 Duo 2GHz Intel Mobile, 2GByte RAM, ATI Mobile GPU.
Using Ubuntu 10.04, PiTiVi from actual package repository.
Tried to combine 2 DV-Videos (PAL, 48Khz Audio) and a background soundtrack.
When a clip starts and ends (overlapping and with a gap to the clip before) I can hear a gap or clicking noise in background audio.
The if overlapping, the video seems to jiggle. Have the same effect in preview and in the rendered result-file. Tried different output-codecs.
If this would work, I would love PiTiVi very much. Its really easy to use and the option with graphical volume envelopes are very intuitive. Thank you.

[Jeff Fortin Tam (kiddo)]

Is this still a problem with 0.13.5 ?

[jpfle (jpfle)]

Yes, it's still a problem with 0.13.5. The previewer lags when 2 clips are not exactly one after the other, so it lags when there's a gap between 2 clips or when 2 clips are overlapped, no matter if the 2 clips are on the same layer or not.

See my attached screencast that illustrates this bug. The video used is the sample file attached to this bug report:

https://bugzilla.gnome.org/show_bug.cgi?id=636773

My config is PiTiVi 0.13.5 on Ubuntu 10.10, and my computer is an Asus EeePC T101MT:

- RAM Memory: 2 GiB RAM
- Processor: Intel Atom 450 (1.66 GHz)
- Integrated Graphics: GMA 3150

[Jeff Fortin Tam (kiddo)]

JP, your issue *might* be a separate problem:
- you're talking about gaps and transitions here, the original reporter didn't have those
- you have an Atom processor. They are mostly crap (I know, I have/had one)
- you didn't specify if your project settings match exactly the clip resolution; if not, then it could be https://bugzilla.gnome.org/show_bug.cgi?id=613416

...but there are quite a few intertwined performance problems: https://bugzilla.gnome.org/buglist.cgi?quicksearch=pitivi+perf

[jpfle (jpfle)]

Jean-François Fortin Tam wrote:
> you're talking about gaps and transitions here, the original reporter didn't have those

In the screencast posted by the reporter (out4-1.ogv), we see at the beginning the bug occurring when 2 clips are overlapped (in 2 different layers), as I referred in my comment.

May the current bug report be the same than https://bugzilla.gnome.org/show_bug.cgi?id=610626 ("[video mixing] playback with multiple clips in the timeline is really slow")?

> you have an Atom processor. They are mostly crap

I don't think that is the problem, because there's no lag when the 2 videos are scotched (no gap). I don't see why a gap between 2 clips would be more CPU intensive.

Also, thanks to pointing me "pitivi+perf" bugs. I think that my gap bug is https://bugzilla.gnome.org/show_bug.cgi?id=615154 ("A lot of frames are dropped during playback after a gap in the timeline").

[Jeff Fortin Tam (kiddo)]

I think this is fixed with the new series now. 0.93 is now available in Ubuntu 14.04's proposed updates, please test.