On Sunday 01 Dec 2002 12:11 pm, Rolf Dubitzky wrote: > On Saturday 30 November 2002 11:30 pm, Jason Wood wrote: > > There are a couple of minor points I think you should know about : > > > > * Occasionally Kdenlive will generate a tiny scene (with a duration of > > something like 1e-14). I'm not sure if they will cause a problem or not. > > Why is that?
Rounding errors - I am doing a simple comparison of if timeA < timeB or not, and sometimes it is but shouldn't be :-) I'm exploring the best way to fix this. > > * At the moment, If there are no clips for a part of the timeline, > > Kdenlive generates an empty scene. I.e. > > > > <scene duration="12.45" /> > > That's fine. At present piave does not allow empty frames, i.e. frames > where no information and all other inconsistencies. PIAVE fixes all such > errors/inconsistencies, but this is actually a 'feature' that can be > switched off. Ok. > > Piave should display black in these situations, I think ;-) > > MovieDVperfect displays a test screen. This way you'll notice directly if > you have such errors/inconsistencies in your timeline. It's trivial to > implement a command to let the user choose what happens with empty frames > (black, white, testscreen, etc.) I think in most cases, people will expect an empty timeline to generate a black video, but I can see cases where having a video equivalent of 0xDEADBEEF would be very useful. See below. > > We need to > > discuss the best way to handle this and overlaying one image onto another > > as well - I think that this needs to be standardised somewhat. > > What do you mean with overlaying? One problem I see is, when you have two > clips on top of each other in the timeline and you have not defined an > operation between the two. In this case piave uses a NullOp which will just > pass through the fame from he first (top) track. Is this what you are > referring to? That behaviour is fine for Piave, in which case the task of setting up overlays will be left on the GUI side. By overlaying, I am talking about the task of placing one video on top of another, as would be done when performing alpha-blend, pic in pic, or any other transition-type effect that you can think of :-) One very large feature that I would like to see (I don't think it would be hard to implement, but I do think it would be hard to implement efficiently) is the ability to use the GIMP-style layer modes. For instance, Normal, screen, addition, subtraction, lightest, darkest, hue, saturation, etc. when overlaying one clip on another. But to be back on topic of when I was talking about 0xDEADBEEF - as soon as we start messing around with alpha channels, performing blue screen effects and the like, it would be useful if there was a way to tell that we have "covered" the entire picture or not with video. I think a test screen that would effectively be the bottom-most layer of every scene would be useful for this purpose. Cheers, Jason -- Jason Wood Homepage : www.uchian.pwp.blueyonder.co.uk
