jay jay - 11 days ago 5
Android Question

Issues with android blur using Renderscript

I am using following code for building blurred background for my imageview.

public class BlurBuilder {
private static final float BITMAP_SCALE = 0.2f;
private static final float BLUR_RADIUS = 25f;

public static Bitmap blur(Context context, Bitmap image) {
int width = Math.round(image.getWidth() * BITMAP_SCALE);
int height = Math.round(image.getHeight() * BITMAP_SCALE);

Bitmap inputBitmap = Bitmap.createScaledBitmap(image, width, height, false);
Bitmap outputBitmap = Bitmap.createBitmap(inputBitmap);

RenderScript rs = RenderScript.create(context);
ScriptIntrinsicBlur theIntrinsic = ScriptIntrinsicBlur.create(rs, Element.U8_4(rs));
Allocation tmpIn = Allocation.createFromBitmap(rs, inputBitmap);
Allocation tmpOut = Allocation.createFromBitmap(rs, outputBitmap);
theIntrinsic.setRadius(BLUR_RADIUS);
theIntrinsic.setInput(tmpIn);
theIntrinsic.forEach(tmpOut);
tmpOut.copyTo(outputBitmap);

return outputBitmap;
}
}


Blur is built fine for most times, but get bad over time, eventually my app crashes without any crash log. Upon running on emulator, I have seen the following error after severe testing:

09-01 15:05:03.230 4624-9758/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.238 4624-9781/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.242 4624-10128/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.242 4624-9610/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.242 4624-9781/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.250 4624-9767/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
09-01 15:05:03.254 4624-9758/? E/RenderScript: rsAssert failed: ret == bytes || mShutdown, in frameworks/rs/rsFifoSocket.cpp at 83
... (same error - many more times and then crash)


I have following queries in this regard:


  1. I am using following gradle config for renderscript:

    compileSdkVersion 23
    buildToolsVersion "23.0.3"

    defaultConfig {
    applicationId "package "
    minSdkVersion 19
    targetSdkVersion 23
    multiDexEnabled true
    renderscriptTargetApi 19
    renderscriptSupportModeEnabled true

    }



What is the recommended version of renderscript library ?
Should I import dependencies from
android.support.v8.renderscript.Allocation or
android.renderscript` package ?


  1. Can I achieve the blur effect without using renderscript library ?


jay jay
Answer

After spending more than a day, I figured out the following:

  1. App is crashing because there is an exception being thrown by Renderscript library. This usually happens often in devices with low processing power. This exception is not a Java exception, cannot be caught.

  2. Use the following code for another way to issue blur (without using renderscript library):

    public static Bitmap fastblur(Bitmap sentBitmap) {
    
    int radius = (int) BLUR_RADIUS;
    
    int width = Math.round(sentBitmap.getWidth() * BITMAP_SCALE);
    int height = Math.round(sentBitmap.getHeight() * BITMAP_SCALE);
    sentBitmap = Bitmap.createScaledBitmap(sentBitmap, width, height, false);
    
    Bitmap bitmap = sentBitmap.copy(sentBitmap.getConfig(), true);
    
    if (radius < 1) {
        return (null);
    }
    
    int w = bitmap.getWidth();
    int h = bitmap.getHeight();
    
    int[] pix = new int[w * h];
    Log.e("pix", w + " " + h + " " + pix.length);
    bitmap.getPixels(pix, 0, w, 0, 0, w, h);
    
    int wm = w - 1;
    int hm = h - 1;
    int wh = w * h;
    int div = radius + radius + 1;
    
    int r[] = new int[wh];
    int g[] = new int[wh];
    int b[] = new int[wh];
    int rsum, gsum, bsum, x, y, i, p, yp, yi, yw;
    int vmin[] = new int[Math.max(w, h)];
    
    int divsum = (div + 1) >> 1;
    divsum *= divsum;
    int dv[] = new int[256 * divsum];
    for (i = 0; i < 256 * divsum; i++) {
        dv[i] = (i / divsum);
    }
    
    yw = yi = 0;
    
    int[][] stack = new int[div][3];
    int stackpointer;
    int stackstart;
    int[] sir;
    int rbs;
    int r1 = radius + 1;
    int routsum, goutsum, boutsum;
    int rinsum, ginsum, binsum;
    
    for (y = 0; y < h; y++) {
        rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
        for (i = -radius; i <= radius; i++) {
            p = pix[yi + Math.min(wm, Math.max(i, 0))];
            sir = stack[i + radius];
            sir[0] = (p & 0xff0000) >> 16;
            sir[1] = (p & 0x00ff00) >> 8;
            sir[2] = (p & 0x0000ff);
            rbs = r1 - Math.abs(i);
            rsum += sir[0] * rbs;
            gsum += sir[1] * rbs;
            bsum += sir[2] * rbs;
            if (i > 0) {
                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];
            } else {
                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];
            }
        }
        stackpointer = radius;
    
        for (x = 0; x < w; x++) {
    
            r[yi] = dv[rsum];
            g[yi] = dv[gsum];
            b[yi] = dv[bsum];
    
            rsum -= routsum;
            gsum -= goutsum;
            bsum -= boutsum;
    
            stackstart = stackpointer - radius + div;
            sir = stack[stackstart % div];
    
            routsum -= sir[0];
            goutsum -= sir[1];
            boutsum -= sir[2];
    
            if (y == 0) {
                vmin[x] = Math.min(x + radius + 1, wm);
            }
            p = pix[yw + vmin[x]];
    
            sir[0] = (p & 0xff0000) >> 16;
            sir[1] = (p & 0x00ff00) >> 8;
            sir[2] = (p & 0x0000ff);
    
            rinsum += sir[0];
            ginsum += sir[1];
            binsum += sir[2];
    
            rsum += rinsum;
            gsum += ginsum;
            bsum += binsum;
    
            stackpointer = (stackpointer + 1) % div;
            sir = stack[(stackpointer) % div];
    
            routsum += sir[0];
            goutsum += sir[1];
            boutsum += sir[2];
    
            rinsum -= sir[0];
            ginsum -= sir[1];
            binsum -= sir[2];
    
            yi++;
        }
        yw += w;
    }
    for (x = 0; x < w; x++) {
        rinsum = ginsum = binsum = routsum = goutsum = boutsum = rsum = gsum = bsum = 0;
        yp = -radius * w;
        for (i = -radius; i <= radius; i++) {
            yi = Math.max(0, yp) + x;
    
            sir = stack[i + radius];
    
            sir[0] = r[yi];
            sir[1] = g[yi];
            sir[2] = b[yi];
    
            rbs = r1 - Math.abs(i);
    
            rsum += r[yi] * rbs;
            gsum += g[yi] * rbs;
            bsum += b[yi] * rbs;
    
            if (i > 0) {
                rinsum += sir[0];
                ginsum += sir[1];
                binsum += sir[2];
            } else {
                routsum += sir[0];
                goutsum += sir[1];
                boutsum += sir[2];
            }
    
            if (i < hm) {
                yp += w;
            }
        }
        yi = x;
        stackpointer = radius;
        for (y = 0; y < h; y++) {
            // Preserve alpha channel: ( 0xff000000 & pix[yi] )
            pix[yi] = ( 0xff000000 & pix[yi] ) | ( dv[rsum] << 16 ) | ( dv[gsum] << 8 ) | dv[bsum];
    
            rsum -= routsum;
            gsum -= goutsum;
            bsum -= boutsum;
    
            stackstart = stackpointer - radius + div;
            sir = stack[stackstart % div];
    
            routsum -= sir[0];
            goutsum -= sir[1];
            boutsum -= sir[2];
    
            if (x == 0) {
                vmin[y] = Math.min(y + r1, hm) * w;
            }
            p = x + vmin[y];
    
            sir[0] = r[p];
            sir[1] = g[p];
            sir[2] = b[p];
    
            rinsum += sir[0];
            ginsum += sir[1];
            binsum += sir[2];
    
            rsum += rinsum;
            gsum += ginsum;
            bsum += binsum;
    
            stackpointer = (stackpointer + 1) % div;
            sir = stack[stackpointer];
    
            routsum += sir[0];
            goutsum += sir[1];
            boutsum += sir[2];
    
            rinsum -= sir[0];
            ginsum -= sir[1];
            binsum -= sir[2];
    
            yi += w;
        }
    }
    
    Log.e("pix", w + " " + h + " " + pix.length);
    bitmap.setPixels(pix, 0, w, 0, 0, w, h);
    
    return (bitmap);
    }
    
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