I have a list of photos in my activity.
I should render those concurrently. so I find the best way to have 3 TextureView at first and change the position of them on scrolling the list. If I create EGLThread each time, It runs correctly, but it has a little delay to update the texture. so I need to have EGLThreads permanently, but I don't know to change the bitmap of each EGLThread. I try so many codes but I couldn't find the solution.
I solved.
should run code in postRunnable in EGLThread
Related
I am still new to Android, and never had to deal with memory management in my previous experience.
In my android application, I have an activity with a TextView, a ListView, and ImageView. I have listeners for the textview and listview, and the code that changes the contents in all three of those views. The contents is stored in the arraylist. The source for the ImageView is stored in form of a String (filenames), and the code that makes the changes looks like this:
tv1.setText(myText);
imgView.setImageResource(myImage);
This worked perfectly well while I only had a few images to test the logic, but once I added more images, I started to get the OutOfMemory error. If I make the images smaller, I get that error a little later in the process, but I still get it.
At first, I thought that Android does not release the previous source, so I thought using recycle() before the reassignment will help. Instead, I've got another error when I try to change the source:
Cannot draw recycled bitmaps
It looks like I am missing some vital understanding about how the ImageView handles the source images. Does it assign the bitmap reference and then keeps the same reference, but somehow changes content?
Then, after reading this article, I realized I have a different kind of problem altogether, the one that might be solved by using the inBitmap. Yet, the documentation says the bitmaps have to be the same size for that, and mine are not.
I am thinking of converting my drawable to bitmap, then scaling it to some hard-coded dimensions, then using inBitmap. I guess my second question is - does this approach make sense? Are there any downfalls in scaling the images? And any examples would be appreciated, of course.
Thank you!
I want to do image processing on frames from Android Camera in real time with OpenCv, but all the OpenCv Android examples provide a preview of the image being captured. I really don't need previews of the frames , is there any way to get the frames without actually showing the preview ?
A quick/naive way would be to make onCameraFrame method returning null and set your CameraBridgeViewBase visibility to SurfaceView.INVISIBLE or SurfaceView.GONE.
I still would like to know if it worked for you, but meanwhile I found the solution that worked for me. As I feel grateful for the guy who wrote it, I'm sharing this (scroll down to answers section) with anyone who will have same problem in future.
In case the link vanished, here's his/her pro-tip:
You can set your preview (in this case a CameraBridgeViewBase)
transparent by setting the alpha value of the view, with 0 being
completely invisible.
mOpenCvCameraView.setAlpha(0);
This should make your preview "disappear".
I wonder how your solution works, because as you can read in the docs:
This method is invoked when delivery of the frame needs to be done.
The returned values - is a modified frame which needs to be displayed
on the screen.
Indeed, in my case it doesn't work but I desperately need such a functionality.
I am stuck showing frame animation in android. My problem is that I have to animate 36 images. The smallest image is 69 kb in size and the biggest(last frame) is 526kb. A total of 11mb. I know its insane but I need to do it. See images below. The app is already made for iphone and I have to port it to android.
Requirements:
smooth animation
no frame loss
consistent with iphone
The solutions I tried are:
AnimationDrawable by providing in xml files. Problems: the start time is almost 6 -12 seconds. Images lose frames so jaggy experience.
Change imageview bitmap inside a handler. Problems: Frame loss and Out of memory
Create a custom imageview class. Define a method showAnimation() and inside it update bitmap and invalidate() the view unitl the last frame. Problems: Not fitting my requirement. This by far gave the best result but not half as required.
I am a noob in opengl and gamedevelopment. I am unable to find any alternative to my problem. Please help.
Smallest image:
Last image:
I can visualize the effect you are aiming at.I guess doing this will require pushing in different images onto the same imageView, with incremental frame rate.|
The accuracy will depend on the number of images you have. Greater the number of images finer will be the precision.
Also you need to implement incremental frame rate. So that it gives a smoother feel.
Doing this should be possible using a simple loop to change the image resource of the imageView Controller. There must be lag between two iterations, this lag will actually be the frame rate.
I think this can give satisfactory results.
Going for openGL, however, you will not need all these images. It will just require one image of the card that will be animated and duplicated to create the final image. This however is a complex piece of task(I think) so if you are catching some dead lines, you must go for a non-openGL solution like the 1st one, I have suggested.
I am doing a project where I want 100 of the same image randomly scattered throughout the screen. In the future, I want an image to disappear when the image is tapped by the user.
I am mainly focusing right now on the most efficient way to display a repeated image. It seems like I could set it up so that the fact that the images are the same makes it more efficient; I'm just not sure how. I do not want to proceed further until I know I have a sound base. I'm using .png files.
I've looked around without a definite answer.
Also, would if be easier to draw my object with two circles (which is what my image is), rather than using a bitmap?
Any clues???
Assuming you're talking about drawing the bitmap on a Canvas object, the method should be pretty straightforward. You load the image into a Bitmap object and keep it as a member of the owning class, and draw it 100 times using canvas.drawBitmap(...) functions.
The other way of doing it is having 100 ImageViews with the same image, but I won't even write the details because this would be truly inefficient!
You can use a listView: http://developer.android.com/guide/topics/ui/layout/listview.html
It shows a list of items, using an adapter to inflate elements. It is pretty simple to use.
I was looking over internet a lot, but only found examples how to text is changed every second or show even miliseconds.
I was using those examples to change picture when second was change, but timer was not accurate anymore. On image change the app respond with random delay for about 20 milisec or 200 milisec.
I was using class Runnable with postDelay and AsynTask where onPostExecute refresh UI, but both working exactly the same with lag.
What is the best practice to change picture every second?
And in the future I have an idea to start animation of 5 images every second (more fancy clock timer).
I would post my code, but now is really a mess of all examples I found till now.
well you have not shared the code so I have to guess only,
I would suggest to have the images as bitmap or drawable initialized already, may be in a hashtable.
After that, start your timer and place the code to replace the image at right place.
Point is you should not spend time other than replacing image in you thread.
Edited:
If you want to do it via code :
before starting your animation create an array of Bitmaps not drawable ids (or the object of Drawble class).
Why because you need to save time spent by system in creating the bitmaps from the ids you provide in array and then set to you image view.
Also, you can use AnimateDrawbles for this which is very easy optimized and reliable.
here is a sample.
Just tune the duration variable in the xml according to your need.