I want to generate a video [let's say 1920x1020] from a 1920x10000 still image.
The image has to scroll, from top to bottom as if someone was actually scrolling a page.
Found answers how to make it with ffmpeg, but i need to scroll it in mlt as i have a lot of other tasks there.
melt -profile atsc_1080p_2997 1.jpg length=300 -filter affine transition.geometry="0=0,0:100%x100%;300=0,-500:100%x100%"
This scrolls, but image is centered and i need to calculate pixels...
Is there any way to make it like with ffmpeg? (generate video containing scrolling image) (just pass needed length)
MLT does not have a similar scroll filter. The method you used is the recommended/preferred way to scroll in MLT.
...i need to calculate pixels
You can use percent instead of pixels if that helps.
You can use the filter and filter service's name is affine.
Related
I have some questions about sliders,
Im using a slider and i want a marker to be present on it like:
http://1.bp.blogspot.com/-HDNFnyRU2Cw/TcuMbBaL70I/AAAAAAAAAGc/7eWN1qnZbAw/s1600/seek.JPG
it draws the image at the bottom of the slider, not on top of it, searched for a setThumbImagePosition or something like that ,but didnt find it, is there a way to use sliders with markers on the top of them?(like the image shown)
Is there a way to show divisions on the slider?(for example this)
https://raw.githubusercontent.com/channguyen/range-slider-view/master/screenshots/sc.png
Whats the best practice to create thicker sliders?
Check out this post notice that in order to create the stars effect properly we wrap the slider in a flow layout to prevent it from growing. You can use background images just like we do in the stars slider but you need to place the slider in a flow layout of similar layout that doesn't let it grow beyond its preferred size.
I need to display many markers on a WPF image. The markers can be lines, circles, squares, etc. and there can be several hundreds of them.
Both the image source and the markers data are updated every few seconds. The markers are associated with specific pixels on the image and their size should be absolute in relation to the screen (i.e. when I move the image the markers should move along with it, but if i zoom in, they should take the same space of the screen as before).
Currently, I've implemented this using the AdornerLayer. This solution has several problems but the most significant one is that the UI doesn't fare well under the load even for 120 such markers.
I wanted to ask what would be the best way to go about implementing this? I thought of two solutions:
Inherit from Canvas and make sure it is invalidated not for every
added marker but for a range of markers at once
Create a control that holds an image and change its OnDraw to draw all the markers
I would appreciate some pointers from someone with experience with a similar problem.
Your use case looks quite specialized, so a specialized solution seems in order. I'd try a variant of your second option — extend Image, overriding its OnRender method.
My aim is to have 3 images shrink, grow, and move along a horizontal axis depending on selection. Using Auto Layout seems to make the images jump about as they try to fulfil the Top space to superview / Bottom space to superview constraints.
So to combat this I have put all the images inside their own UIView. The UIView is set to the maximum size the images can grow to, it is centred on the horizontal axis. So now all the images must do is stay centred inside their corresponding UIView. This has fixed my problem as the UIViews perform the horizontal translation, while the images shrink/grow inside while remaining centred. My question is - is this the correct way to do this? It seems very long and like I am perhaps misusing the ability of Auto Layout. I have to perform similar tasks with more images and so any advice is welcome! Thanks.
I've just written a little essay on this topic here:
How do I adjust the anchor point of a CALayer, when Auto Layout is being used?
Basically autolayout does not play at all well with any kind of view transform. The easiest solution is to take your view out of autolayout's control altogether, but alternatively you can give it only constraints that won't fight back against the particular kind of transform you intend to apply. That second solution sounds like just the sort of thing you're doing.
I'm looking for component, that would allow me to show and manipulate single image in a same way as native image browsing in Pictures hub.
I want:
Pinch to zoom image (with top and bottom limits)
Drag to move image around, but I don't want it to get out of bounds of screen. Spongy behavior is optional.
Double tap to toggle between original size and fit-to-screen size.
Does such component exist? Preferably free. If it doesn't, then I need to implement everything myself.
There is a multiscale image with deepzoom image as a source. Now I need to allow users to draw poligons and lines on top of the multiscalimage in such a way that the shapes will follow drag and zoom to scale accordingly.
I tried to add a canvas in addition to the multiscaleimage but can't figure out how to make them stick to each other on zoom or drags.
If you have done any user shape drawing on top of deepzoom image, please share your methods.
Thanks,
Val
Have you checked the Silverlight 4 Puzzle demo?
http://johnpapa.net/silverlight/silverlight-4-html-puzzle-how-does-it-work/
You may be able to get some "inspiration" by inspecting this app.
Follow the link to download the source:
http://www.silverlight.net/community/samples/silverlight-4/html-puzzle/
I've done this before. Not sure if this is the preferred/optimal way, but you can add layers to your root deepzoom layer. (sorry, i forget the proper terminology).
In my case i had 4 sub layers, some of which were used to render lines and shapes, others were used to render entire maps that were loaded from a URI.