How do I know how long an animation lasts and how do I stop the gif at the end?
I created a GIF from export tool (Maple) but I don't know how long the animation is, or how to make GIF run in real time. I made a gif for showing how something falls down from an altitude. I need to show some figures like t(time) , h(height), v(speed) while it falls down.
Commands that generate animations in Maple often have an option that controls the default number frames. For example, the plots:-animate uses 25 frames. Moreover, animations that are shown in the Maple GUI can be controlled by the animation toolbar, which sets animations to run at 10 frames per second (fps) by default. When you use the right-click menu to export your animation to a GIF file, the exporter will take the current setting for fps into consideration and produce an animation that is 25 frames / 10 frames per second = 2.5 seconds long. Changing this value in the animation toolbar will result in shorter or longer animations accordingly.
From a couple of quick tests, exporting the animation programmatically does not respect the choice of fps, so in this case you may need to play with the number of frames in order to compensate for the default 10 fps setting.
With respect to stopping the gif, as far as I know, there is no way to control this using Maple. I believe that the only solution is to use a GIF editing program to manually turn off the 'loop' option.
Related
So here's my setup:
Camera images coming in at 1920x1080 # 25 FPS
Writing image data to WriteableBitmap on UI thread (simple copy, no processing)
Two Image controls in two different windows on two different monitors has their Source property set to the WriteableBitmap
Some generic UI stuff goes over the camera images
This works great, uses about 4% CPU on an old laptop (8 logical processors). The video is as smooth as can be. However, my UI has some animations (stuff moving around). When the camera display is running, those animations gets choppy.
Right now, the camera image is in Gray8 format, so it will be converted (I guess when calling WritePixels?). I also tried forcing one of the animations to 25 FPS too, no change.
Where should I start to resolve this? Is the issue that I'm locking the bitmap for too long, or is there something else going on? From what I can see locking the bitmap will cause the render thread to block, so moving that to another thread seems pointless. And it does feel like that somewhat defeats the purpose of WriteableBitmap.
This is always going to be tricky because you're capturing at 25FPS whilst WPF tries to update at 60. It's difficult to offer any meaninful advice without seeing a testable project but I'd probably start by doing the updates in a CompositionTarget.Rendering handler.
I want to make an animation in the Silverlight 4 Expression Blend 4 - a running man.
How is it possible to do, because the only way I see it to be done is to draw him frame by frame with the interval, say, 0.2s?
Your options are bitmap animation or key-frame animation of body parts.
Key-frame animation seems appropriate unless you want photo-realistic movement.
You will need to select regular time internals in Blend and place the various components of the man (legs segments, arm segments etc) in the correct positions for that key frame. Silverlight will do the interpolation between frames.
Build up one complete cycle and set the storyboard property to repeat the sequence.
I'm using VB.net 2010 and WPF 4. I need to have a smooth transition between two videos played on the mediaelement. I absolutely cannot use anything that requires me to use a winhost in the WPF window, as that will make my project impossible (since the video is full screen, and the controls are over the video)
Basically, I need for the video to play through, and then smoothly go to another video specified in code behind. I cannot splice the two videos together - they must be separate.
How do I have the videos transition smoothly, with no "blink"?
I'm guessing without testing here. You're probably going to need some CPU cores and a good video card.
If you have the memory, use two MediaElements.
Queue up both videos, one on each element.
Set the opacity of the second one to completely transparent. They're UIElements so this should work...
Use timers of some kind keyed from the start of playback on the first one so that you get an event a couple of seconds before playback ends.
With that event delegate, start the video in the second MediaElement, animate the first one's opacity to zero while simultaneously animating the second one to fully opaque.
If you need to do it again, set up the timer again and make sure your delegate animates things the other way.
I have a few fairly simple animations (moving text around, moving ellipses etc.) and running in full screen (1920x1080 minus the task bar) the WPF Performance Suite reports a good framerate around 50 FPS throughout the animation. Dirty Rect Addition is somewhere around 300 rect/s, the SW frames are between 0 and 4 and the HW frames are between 3 and 5. Video memory usage is around 80 MB.
Problem is that the animations stutters every other half second. It is definitely not fluid :-(
My machine is a new Dell laptop XPS 15 with the GeForce GT 435 with 2GB memory. - The drivers are up to date. (The same behavior occurs on my netbook (in full screen) as well so I don't think it is hardware related.)
If I make the window smaller the stutter goes away.
The stutter occurs with the simplest of animations - even with just a couple of elements but adding more elements certainly makes it more noticeable.
How can I find out what causes this stutter?
When I think of it, I have not actually seen any WPF animations which run smoothly in full screen. Is this even possible?
Have you tried to set a lower "max frame rate" to the animation?
<Storyboard Timeline.DesiredFrameRate="10">
<!-- ....blah blah blah -->
</Storyboard>
If your animation is causing massive recalculation of child or parent elements, changing the DesiredFrameRate will have a cascading effect on the number of calculations made by the system.
Also, check out the "Remarks" section of this link. It explains why/when you should use it.
If setting a lower frame rate fixes your stuttering, then you need to consider simplifying your XAML to limit the amount of recalculation needed at every frame of your animation (limiting the number of child or parent objects resized - or affected in any way - by every frames/changes made by the animation.
You might want to also check out the "WPF Performance Suite". It is an awesome set of tools to determine what exactly is going on in your WPF app, seeing which parts of your window are being repainted and when, and the CPU usage of each of your XAML elements!
Hope this helps!
Patrick,
I have no answers. All I can do is provide some solidarity. I'm trying to animate an ItemsControl. The concept is pretty simple, really. I've got a ListView and in the ListView I have a GridView. I want the items in the GridView to to smoothly go from one row to another row as the underlying list is sorted so that, for example, a sorted list will stay sorted as the values in the list change.
I've noticed this: animation on moderately complex controls is a CPU hog. The stuttering I'm pretty sure is simply related to the CPU being maxed out (I noticed you didn't provide the CPU graph on your dump above). Keep the CPU around 50% and the animation appears smooth, above 75% and you get these stutters.
Still working on the problem, but I think it goes deeper than my code.
Don
I had a similar issue where it was stuttering, nothing really major it just looked like little stutters here and there while I ran the program. On a hunch, I shut down Google Chrome while it was running and that fixed it,the scrolling became completely smooth...
So my advice would be if you have any internet browsers open check to see if closing them out fixes the problem.
I've created a WPF control (inheriting from FrameworkElement) that displays a tiled graphic that can be panned. Each tile is 256x256 pixels at 24bpp. I've overridden OnRender. There, I load any new tiles (as BitmapFrame), then draw all visible tiles using drawingContext.DrawImage.
Now, whenever there are more than a handful new tiles per render cycle, the framerate drops from 60fps to zero for about a second. This is not caused by loading the images (which takes in the order of milliseconds), nor by DrawImage (which takes no time at all, as it merely fills some intermediate render data structure).
My guess is that the render thread itself chokes whenever it gets a large number (~20) of new BitmapSource instances (that is, ones it had not already cached). Either it spends a lot of time converting them to some internal DirectX-compatible format or it might be a caching issue. It cannot be running out of video RAM; Perforator shows peaks at below 60MB, I have 256MB. Also, Perforator says all render targets are hardware-accelerated, so that can't be it, either.
Any insights would be appreciated!
Thanks in advance
Daniel
#RandomEngy:
BitmapScalingMode.LowQuality reduced the problem a little, but did not get rid of it. I am already loading tiles at the intended resolution. And it can't be the graphics driver, which is up-to-date (Nvidia).
I'm a little surprised to learn that scaling takes that much time. The way I understood it, a bitmap (regardless of its size) is just loaded as a Direct3D texture and then hardware-scaled. As a matter of fact, once the bitmap has been rendered for the first time, I can change its rotation and scale without any further freezes.
It's not just with a large number of images. Just one large image is enough to hold up rendering until it has been loaded in, and that can be quite noticable when your image dimensions start getting up in the thousands.
I do agree with you that it's probably the render thread: I did a test and the UI thread was still happily dispatching messages while this render delay was taking place from trying to display a fully pre-cached BitmapImage.
It must be doing some sort of conversion or preparation on the image, like you were speculating. I've tried to mitigate this in my app by "rendering" but hiding the image, then revealing it when I need to show it. However this is less than ideal because the rendering freezes happen anyway.
(Edit)
Some followup: After a discussion on the MS WPF alias I found what was causing the delays. On my Server 2008 machine it was a combination of old video drivers that don't support the new WDDM driver model and a delay for resizing the image.
If the source image size is different from the display size, that will delay the render thread before the image shows up. By default an image is set to the highest quality, but you can change the scaling options for rendering by calling RenderOptions.SetBitmapScalingMode(uiImage, BitmapScalingMode.LowQuality); . Once I did that, the mysterious freeze before displaying an image went away. An alternative, if you don't like the quality drop in scaling, is to load the BitmapImage with DecodePixelWidth/Height equal to the size it will be displayed at. Then if you load the BitmapImage on a background thread, you should have no delay in displaying it.
Also try these;
/* ivis is declared in XAML <Image x:Name="iVis" UseLayoutRounding="True" SnapsToDevicePixels="True" /> */
iVis.Stretch = Stretch.None;
RenderOptions.SetBitmapScalingMode(iVis, BitmapScalingMode.NearestNeighbor);
RenderOptions.SetEdgeMode(iVis, EdgeMode.Aliased);
VisualBitmapScalingMode = BitmapScalingMode.NearestNeighbor;
iVis.Source = **** your bitmap source ****
I was having some trouble with performance when using a huge amount of "A" channel color's, waiting until after the image had rendered to scale it worked much better for me.
Also, as you said your using a tiled graphic?
You would usually use a TileBrush to simply set as the Brush on your FrameworkElement. If you are animating them or adding new ones dynamically, you could generate your brushes then apply them to your object as you go manually too, be sure to Freeze them if you can. Also, VisualBitmapScalingMode is a property of any Visual.