- It is explained clearly what the feature is supposed to do
- It is clear how this can be implemented in Kdenlive
- Usability and consistency is checked
- has to be implemented before Trimming
- What kind of video transitions are used? Simple blending or any?
- What Does It Mean To Crossfade Audio?
- Same track transition in short sametrack_transition.pdf
- Transitions in the handbook
- Same track transition in MLT see "Introducing the Mix" and "Practicalities and Optimisations"
- Same track transition in melt
Before: ┌────────┐┌──────────────┐ │Clip A ││ Clip B │ └────────┘└──────────────┘ After: ┌───────┲━━━┱────────────┐ │Clip A ┃CF ┃ Clip B │ └───────┺━━━┹────────────┘
In Audio, cross-fading refers to the process of fading out one audio track while fading in another one. For same-track cross-fading, this is typically accomplished by the user by letting two audio clips overlap each other, which automatically generates a cross-fade effect.
- Fading is desired to avoid clicking noise when cutting audio if the audio curve does not end at 0.
- Cross-fading is desired to transition seamlessly from one recording to another, e.g. two consecutive recordings
- Same-track cross-fading is useful because only one track is needed.
The same applies for video clips where the images of the two clips are blended together.
- When we have 2 adjacent clips you place the cursor in the middle of the cut and you hit the key. The type and duration of the transition is set by default and configurable by the user. This works on the audio too.
- Only the active tracks receive the command if there are corresponding cuts on the other tracks.
- If you hit the key when the cursor is placed at the end of a clip the transition is applied on the tail of the clip.
- The overlap is calculated referring to the cut. About this you can find examples and images in the document sametrack_transition.pdf.
- The clips are invisibly resized by using frames after and before the cut if available. If no frame exists after the out point of the previous clip and before the following clip the transition can't be applied.
- The transition should be resizable and slidable by the mouse and fine controlled by a widget.
- Kdenlive should warn when you have not enough frames to fill the default length.
In video editing applications, there are two different approaches to add a cross-fade between two clips A and B:
- Drag clip B to the left so it overlaps clip A. The overlapping section then becomes a cross-fade section.
- Select clip A and use a keyboard shortcut to add a cross-fade between those clips. This variant is used mainly by professional video editing appliations.
What tasks are included?
- Method to create a cross-fade (either via keyboard or via mouse) and modify its duration
- Visual representation of the cross-fade in the timeline
- Cross-fade effect with an ease-in/out function (e.g. sine instead of just linear)
- Method to remove a cross-fade again