Greetings,

Dave Phillips here. I write a twice-monthly column for the Linux Journal:

http://www.linuxjournal.com/user/800764/track

I review audio and video software for Linux, so of course I'm writing a review of Kdenlive. I've been using the SVN sources, and I'd like to share a few thoughts with the devs.

First, the program is sweet, I like it a lot. The interface design is excellent, by far the best I've used in a Linux video editor. Transitions in Kdenlive are easy to define and manipulate, and I love the inclusion of the DVD Wizard, that's a nice touch.

Alas, performance is an issue. I have the most problems when editing multitrack layouts, with random crashes occurring often enough that I find myself "saving early, saving often". Hopefully such issues will diminish as the work evolves. I hope so, because Kdenlive has so many attractions. Meanwhile I'm keeping up with the SVN sources and will continue to use & test the new code.

Also, Kdenlive *needs* JACK. Like, yesterday. :) Connectivity to applications such as Ardour, JACK-Rack, Open Octave, and other JACK-aware applications would be a giant win for everyone. LiVES already has basic support for JACK's audio server and its transport control. I also like LiVES a lot, but IMO Kdenlive got the UI just right.

Anyway, thanks for the fine software, and I wish you all continued success in the development of Kdenlive.

Best regards,

Dave Phillips

http://linux-sound.org

Hi Dave!

Just to put AlgorithMan's bashing into perspective.

He says "I've been using kdenlive for around 2-3 years". Yet, he joined only yesterday and his two-part rant is the only contribution here so far. So take his statements with a grain of salt. A big one. I mean, like Ayer's Rock.

"I've been using kdenlive for around 2-3 years now and trust me: that's not going to happen... for everything they fix, they **** up something else..."

What happen ?

i can use kdenlive for 3 hours without any crash ...

You are writing a troll, we don't need you go away ..

It crashes for me about 1 - 2 times per hour, so I for me cannot say, that kdenlive doesn't crash. Though I wouldn't say, it is messed up. It works like it should after restart.

A little update: I'm now using revision 3999 from SVN and it seems that the program is more stable. I haven't done anything big with it yet, but I have some large AVI and DV files I'll pop into it and see what happens when I play with them.

Best,

dp

Hi Dave,

Some of these comments are overly negative. I view the development of kdenlive/mlt as very positive and progressive. I've been following Kdenlive for over a year now (really). These last few releases (0.7.4+) have shown really good progress and I would now recommend the program to friends. I find the current kdenlive to be quite stable and useful with a few caveats.

1) I found that I need to use the SVN versions or most current releases rather than the Ubuntu packages. That means compiling SVN kdenlive, GIT mlt, and other depndencies such as updated ffmpeg or frei0r (as I did for Jaunty). I put part of the blame on Ubuntu/Debian for it's slow uptake of media programs. After updating a few of the dependencies it starts to add up and it gets difficult removing some packages and not others.

2) I also found that it can be picky on out of spec a/v files or maybe some formats I don't use. For example, it's very stable when I use all brand new DV or HDV captures from my canon HV30. However, I have run across some formats that cause trouble in the past. Video format variations seem to be really out of control in general.

3) I had problems in the past using old project files with newer versions of kdenlive. I would suggest that you do your project with one version of kdenlive before upgrading and moving on. I don't think the format is meant to last forever. Maybe this is the source of some confusion. i.e. start a project in 0.7.5 and finish it within a few months before 0.7.6 comes out.

I have also experienced the need to save often, but it has gotten much better in the past 6 months with the recent versions.

The developers appear to be dedicated and involved. I've reported bugs in the past and they appear to take them seriously and fix things. Of course they probably cannot help if you have some obscure format or are not willing to help with bug reporting and testing.

BTW - I've read some of your articles about audio and enjoyed and found them useful.

Geoff

Regarding the stability comments.

I found stability to improve when I transcoded my source AVCHD files and worked with the transcoded clips. It should be noted that video players (mplayer, Dragon) also caused crashes. Investigation is ongoing but the video drivers (nVidia 180) are on the suspect list.

First, my thanks to all who responded to my original message. My review is written and submitted, but it hasn't been published yet. I'll notify this list when the article goes on-line.

Btw, I started with rev 3962 and ended with rev 3999 of the SVN sources. Stability was much improved by that version, as I point out in the article. However, there are some issues/features that I'd like to see addressed:

JACK support. Gotta have it. Kdenlive lacks pro-audio capability without it.
LADSPA/LV2 audio plugin support.
Support for my Logitech webcam (that works fine with other webcam apps).
Looping and/or loop paste.
A simple fade-in/fade-out plugin, ditto for a cross-fader.
Call-out to an external audio editor.

Nothing critical there, but those additions would certainly increase Kdenlive's value in my studio.

Again, my thanks to the developers for this very cool app. I hope stability remains a key focus, and I will definitely continue to watch and test Kdenlive's development.

Best,

dp

I used to crash kdenlive a lot, until I stopped putting videos on track 0, and put them only on track 1 and track 2. For some reason when making transitions from track 1 to track 0, kdenlive would crash. But now that I reserve track 0 for effects other than videos, I do not get many crashes. I put audios on tracks 3 and 4.

I suspect everyone has their own method to reduce crash frequency

Yes you are right.

And note that the "track 0 bug" (1155 on mantis bug tracker) is solved since svn revision 3918. So with the O.7.6 release of today you can now use track 0 to drop some videos. Many other crashes causes have been solved too.

dp: A simple fade-in/fade-out plugin, ditto for a cross-fader.

Fade-in/out as in fade to/from black? That's in there.
Cross fader as in dissolve from one scene to another? Ditto.

At least both of those are in there when you install Ubuntu packages with all the suggested goodies.

'Call out to an external audio editor' - Don't know if you're aware - my version of Kdenlive 0.7.5 is linked to Audacity - select an audio clip and go to Project - Edit Clip should have a little Audacity icon next to it. It will open the clip in Audacity.

This review would seem very audio centric. Of course it would be nice to see Kdenlive having super pro audio features, though it might be nice to start with some basic audio features first, like a mic-voice-over recording feature, for instance. For that matter, not really sure how you can expect it to have pro audio features when there are still quite a number of pro video features it lacks. First things first. :)

> JACK support. Gotta have it. Kdenlive lacks pro-audio capability without it.

MLT (the engine of Kdenlive, if you were not aware) already has some support for JACK as a filter. I basically took the Jack-Rack code and split it between a frontend and library. Then, I used the library to make a MLT filter where audio goes out JACK, through Jack-Rack, and then back into MLT via JACK. The workflow idea is to prototype a set of LADSPA filters inside Jack-Rack running MLT audio realtime through JACK. Then, save the rack file, and you can supply the rack XML file to another MLT filter that does not use JACK - it just uses the rack XML as a LADSPA stack definition. Greater usage of JACK including transport sync is on the long ToDo list.

> LADSPA/LV2 audio plugin support.

LADSPA support is there, but Kdenlive disguises them restricts you to its selection. Probably it should use the RDF data to enumerate them and generate the UI. For now, it is fairly easily to add more by creating Kdenlive effects XML files. LV2 is on the ToDo list.

> Support for my Logitech webcam (that works fine with other webcam apps).

See FFmpeg; Kdenlive just uses FFmpeg directly for this.

> A simple fade-in/fade-out plugin, ditto for a cross-fader.
> Call-out to an external audio editor.

Already there as mentioned in another comment. For external editor, in Settings, goto Environment > Default apps.

@ArtInvent - You wrote:

"This review would seem very audio centric."

Actually it's not. I've been reviewing Linux A/V editors for a few months now, I've tried to keep my focus balanced between video and audio capabilities. If I seem a bit too critical about Kdenlive's audio features perhaps it's because I'm not finding much to complain abut re: its video features. :)

And thanks for the tip re: Audacity, I'll correct the note in my article.

@MichaelNW - I realized afterwards that I'd already answered my own question re: the fades, sorry for the noise. The term Dissolve tends to confuse me, I'm more used to the audio terminology. Yes, I am an old dog trying to learn new tricks. ;)

Best,

dp

Cool. Look forward to the review.
I guess I'm a Kdenlive booster because it's pretty clearly the most advanced video editor on Linux, and because NLE's have been one of the most underserved areas on Linux for a while. Whereas for audio it almost seems like there's an embarrassment of riches, between Audacity and JACK and Rosegarden and Ardour and I'm sure I don't have to tell you. I would just like to see video develop to that point. When the video image processing and manipulation side equals the things that are already possible with sound, well, it's gonna be pretty awesome.