Hi everyone,

After using Kdenlive on a little project I have listed all the problems I encountered during the editing (see topic http://www.kdenlive.org/forum/jambon-volant-origins-short-film-edited-kdenlive to see the video).

Some of them are pretty small, but some other ones made the experience a bit painful. I'll be filling in plenty of Mantis tickets pretty soon, but in the meantime, here is this little list (confirmed on latest packages from the sunab2 repository) :


***** Sound *****

o Volume effect :
- The effect needs a minimum of 2 keyframes to work, but quite often you just want to change the volume of the whole clip. The ideal workflow would be to have no keyframes when first adding the effect then being able to add them wherever you need them. No bug deal but it would make it easier.
- The scaling of the actual volume doesn't seem ideal. You need to change the volume quite dramatically (going from a 100 value to 10 for instance) to actually hear a significant difference. I would expect 50 to be have as loud as 100. Of course it all depends on what the value represents (decibels ? amplitude ?). A solution would be to actually have the values in decibels (default being 0db).
- It is not possible to combine the volume effect with a fade in/out. When setting the volume to 10 and adding a fade out, the volume will actually go back up to 100 before fading out. So when using the volume effect you have to do the fades manually.

o A global volume setting for each track would be very useful (for instance when using one track for music, another for sound effects etc.)

o A volume output indicator would be quite useful to check the output volume and keep a constant volume throughout the whome project (I think Premiere has such a widget by default on the right of the timeline)

o Sometimes (it happens fairly often but it's difficult to reproduce...) when a lot of clips or used, some of them stop outuputting sound. After moving thing arround a bit or working on a different part of the timeline, the sound will come back. I'm not sure whether the sound disapearance is only during the editing or also after a render... It would seem to be some sort of memory management problem, it's the only explaination I can come up with.

o Sound and video should be automatically separated (but grouped) when inserting a clip in the timeline. If you don't separated audio from video immediatly you can forget a video clip has audio. Any serious editing while require sepateing audio from video anyway, so you might as well cut out the extra step and do it on insertion. Premiere works that way and it's fine.


***** Video *****

o It is not possible to overlay several transitions. For instance if you have a clip crossfade to another clip, you cannot have a title clip on top of that transition because it will use a composite transition. The result wil be just the tile on a black background.

o No reverse playing of clips. Either an option to play a clip backwards, or a "reverse" effect or even being able to specify negative values to the speed effect (-100% would be reverse) would be quite nice.

o The names and description of effects

o Pressing "deleted" when an effect is selected should delete the effect, not the clip !


***** Rendering *****

o The worst problem was clearly the crashes. After some stage, every render would result in a crash, and usually close to the end. When using two passes it would crash right at the end of the second pass. The error message is : "Rendering of **** aborted, resulting video will probably be corrupted.". Because of that I never came up with a final 16/9 render for uploading on Youtube.

o The presets aren't really self explaining and to do some advanced configuration you need to edit directy the ffmpeg command line... Not really intuitive ! There are also no lossless presets (huffyuv for instace) ! A preset configurator giving simple option like "codec", "bitrate", "passes", "aspect ratio" etc. would be a lot easier to use. The avidemux interface is really quite good in that regard. The best solution now would be to render to a lossless format with Kdenlive and then use avidemux to compress.

o Render to file is at the same time a drop down list and a button... It's a bit confusing and it's easy to click on the button when you want to open the drop down list. There should simply be a drop down list to choose between "render to file" and "generate script", and next to that a Render button.


**** General *****

o Random crashes ! During the editing Kdenlive frequently crashed, but with no consistent reason. I can't reproduce it easily (could have to do have an hour or so of editing to get a crash), but the error message was always the same...



Well, thanks for reading ! I will add everything to the bug tracket in due course.

It looks like a long list, but actually most of it is only detail, and should those issues be attended to (mostly the sound issues when working on many clips, the random crashes and the render crashes), Kdenlive will be truely be competitive will low end video editing programs such as Premiere Elements, Ulead Video Studio and such. It looks like version 0.8 will be pretty much a 1.0, no ?

With OpenShot quickly catching up feature-wise, we should soon have two usable video edting programs on Linux !

- There is a "gain" audio effect that does not use key frames.
- You can choose "Split audio" on a clip to put the audio on the audio track and grouped with the video. I am not yet in agreement that should be the default. Perhaps there should be a setting to make that automatic.
- It is possible to overlay transitions, but of course not between the same 2 tracks at the same region. If you are layering transitions between more than 2 tracks, then it can be a little tricky.
- There is a HuffYUV+PCM AVI render option. Maybe you did not look in the Lossless/HQ "Destination" drop-down.

Thanks for your answers.

- Gain effect : I've just checked and it is there ! I just didn't notice it because it was not in same the category (audio correction) as the Volume effect. Having it in the same place would be more logical.

- I'm convinced "split audio" should be the default, or at least have it as an option. For instance I kept expecting the fading out on video clip to actually fade out the video and not the audio (even if there is no audio...). It would just make things less confusing.

- As I said, I have not yet managed to overlay transitions between more than two tracks. The most common example is having a title over a clip (and therefore a composite transition) and doing a crossfade between that clip and another. Three clips, two transitions -> doesn't work. Another example would be for instance adding multiple videos (or pictures) with alpha over. These two examples make use of the composite transition, so the problem isn't so much overlaying any transitions (quite rare), but simply overlaying a composite transition with any other one. I always found composite as a transition was a bit weird anyway, because making transitions between clips isn't it's main purpose. Having it as an effect might be a solution (you would maybe select from a dropdown list which track it would composite with...).

- Thank for the tip about the "destination" drop down. I spent quite some time in the render windows but I never thought of changing from the default "File Rendering" (because that is what I wanted to do, after all). There are loads of usefull presets in there and I never knew they existed... Really not obvious ! Having those categories as folders in the the right column (like the effect list) would probably be better.