Hi guys,

You may have noticed that I'm working on a program to convert an animated GIF to a bootanimation.zip.

I have almost everything working, but I realized something today: My converted PNGs don't work!

I can take an animated GIF and convert it into PNGs via a command line tool, and put them in a zip, and everything works. When I do the same with my tool it creates an almost identical image (slight differences in resize algorithm), but when I package them into a bootanimation.zip and put it on my phone it just shows a black screen on boot.

Here is an example of a working boot animation I made (created with command line utilities):
http://dl.dropbox.com/u/68531860/bootanimation.zip

and here is the same animation NOT working (created with my Java program):
http://dl.dropbox.com/u/68531860/bootanimationJ.zip

Here is my code:

Code (Text):

1. import java.awt.Graphics;
2. import java.awt.Graphics2D;
3. import java.awt.RenderingHints;
4. import java.awt.image.BufferedImage;
5. import java.io.*;
6. import java.util.Iterator;
7. import javax.imageio.*;
8. import javax.imageio.metadata.IIOMetadata;
9. import javax.imageio.metadata.IIOMetadataNode;
10. import javax.imageio.stream.*;
11.  
12. public class test {
13.  
14.     static BufferedImage background; // background (for optimized GIFs)
15.  
16.     public static void main(String[] args) throws Exception {
17.  
18.         Object input = new File("img.gif");  // or Object input = new FileInputStream("animated.gif");
19.         ImageInputStream stream = ImageIO.createImageInputStream(input);
20.         Iterator<ImageReader> readers = ImageIO.getImageReaders(stream);
21.         if (!readers.hasNext())
22.             throw new RuntimeException("no image reader found");
23.         ImageReader reader = (ImageReader) readers.next();
24.         reader.setInput(stream);
25.        
26.         int n = reader.getNumImages(true);
27.         System.out.println("numImages = " + n);
28.  
29.         for (int i = 0; i < n; i++) {
30.  
31.             // get metadata (in order to detect framerate and top/left positioning for each frame)
32.             IIOImage frame = reader.readAll(i,null);
33.             IIOMetadata meta = frame.getMetadata();
34.             IIOMetadataNode imgRootNode = (IIOMetadataNode) meta.getAsTree("javax_imageio_gif_image_1.0");
35.            
36.             // get framerate for animation
37.             if (i == 0) {
38.                 IIOMetadataNode gce = (IIOMetadataNode) imgRootNode.getElementsByTagName("GraphicControlExtension").item(0);
39.                 int delay = Integer.parseInt(gce.getAttribute("delayTime"));
40.                 System.out.println("DELAY: " + delay);
41.             }
42.  
43.             IIOMetadataNode imgDescr = (IIOMetadataNode) imgRootNode.getElementsByTagName("ImageDescriptor").item(0);
44.             int offsetX = Integer.parseInt(imgDescr.getAttribute("imageLeftPosition"));  // find offsets for each
45.             int offsetY = Integer.parseInt(imgDescr.getAttribute("imageTopPosition"));   // frame in the animated GIF
46.  
47.             BufferedImage overlay = reader.read(i);
48.             if (i == 0) { background = reader.read(i); }
49.  
50.             // combine current and previous frame to create complete frame (in case of optimized GIFs)
51.             BufferedImage combined = new BufferedImage(background.getWidth(), background.getHeight(), BufferedImage.TYPE_INT_ARGB);
52.  
53.             // paint both images, preserving the alpha channels
54.             Graphics g = combined.getGraphics();
55.             g.drawImage(background, 0, 0, null);
56.             g.drawImage(overlay, offsetX, offsetY, null);          
57.  
58.             // create new directory for images
59.             if (i == 0) {
60.                 new File("bootanimation/").mkdirs();
61.             }
62.            
63.             // resize frame to fit screen
64.             int resizeWidth;
65.             int resizeHeight;
66.             if (background.getWidth() > background.getHeight()) {
67.                 resizeWidth = 480;
68.                 resizeHeight = 320;
69.             }
70.             else {
71.                 resizeWidth = 320;
72.                 resizeHeight = 480;
73.             }
74.            
75.             // Create new (blank) image of required (scaled) size
76.             BufferedImage scaledImage = new BufferedImage(resizeWidth, resizeHeight, BufferedImage.TYPE_INT_ARGB);
77.             // Paint scaled version of image to new image
78.             Graphics2D graphics2D = scaledImage.createGraphics();
79.             graphics2D.setRenderingHint(RenderingHints.KEY_INTERPOLATION,
80.             RenderingHints.VALUE_INTERPOLATION_BILINEAR);
81.             graphics2D.drawImage(combined, 0, 0, resizeWidth, resizeHeight, null);
82.             graphics2D.dispose();
83.            
84.             // rotate the image if it's wider than it is tall
85.             if (scaledImage.getWidth() > scaledImage.getHeight()) {
86.                 ImageIO.write(rotate270(scaledImage), "PNG", new File("bootanimation/img" + String.format("%04d", i) + ".png"));
87.             }
88.             else {
89.                 ImageIO.write(scaledImage, "PNG", new File("bootanimation/img" + String.format("%04d", i) + ".png"));
90.             }
91.             background = combined; // save our most recently created frame as the background for the next frame (in case of optimized GIFs)
92.         }
93.         stream.close();
94.  
95.     }
96.    
97.     public static BufferedImage rotate270(BufferedImage img) {
98.         int width = img.getWidth();
99.         int height = img.getHeight();
100.         BufferedImage newImage = new BufferedImage(height, width, img.getType());
101.  
102.         for (int i = 0; i < width; i++)
103.             for (int j = 0; j < height; j++)
104.                 newImage.setRGB(j, width - 1 - i, img.getRGB(i, j));
105.  
106.         return newImage;
107.     }
108.    
109. }

Please help me figure out what the difference is between my working and non working PNGs!

 

I'm not aware of any PNG compression, but I guess it's possible that the ImageIO.write() method causes this in some way. The zip file is not compressed at all (I do the zipping part myself for testing, and zipped it the same way as the working animation).

 

I read somewhere that 32bit images are supposed to work, but I will try 24. I know the permissions are okay because I've done numerous "sanity checks" with working animations. Thank you both for the input.

 

Making them 24bit did not fix it.

 

32bit means it has an alpha channel, 24bit means no alpha. (8 bits for each color, Red, Green, Blue, and optionally, Alpha) So, removing the alpha did not fix it.

However....

I did get it working! I'll be posting an alpha release either today or tomorrow. All I have left to do is clean up the code, and add the piece that zips the files.
Can't decide if alpha release will have GUI, might wait for beta.

Thank you all for your input.

 

I ended up having to try about a dozen different libraries for writing out a PNG file. Finally found one that worked: org.apache.xmlgraphics.image.codec.png.PNGImageEncoder

You'd be surprised how many other libraries just don't write the correct metadata.

 

First version released! http://androidforums.com/samsung-transform-ultra/533275-gif2boot-convert-animated-gifs-boot-animations-v0-1a.html