Bitmap OOM·ÖÎö

Óöµ½Ò»¸öBitmap¡¡OOM,µ«ÏÈÈëΪÖ÷µÄÈÏΪÊÇÄÚ´æй¶ÎÊÌâ¡£ÖصãÔÚÒ»²½²½µÄ·ÖÎöÖУ¬¸ù¾ÝÊý¾ÝµÃ³ö±ÀÀ£Ô­Òò¡£

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Crash Log

    java.lang.OutOfMemoryError: Failed to allocate a 48771084 byte allocation with 16771032 free bytes and 29MB until OOM
        at dalvik.system.VMRuntime.newNonMovableArray(Native Method)
        at android.graphics.Bitmap.nativeCopy(Native Method)
        at android.graphics.Bitmap.copy(Bitmap.java:592)

48771084 byte / 1024 / 1024 ~~ Ô¼46.51M
16771032 byte ~~ Ô¼ 15.9941M

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·ÖÎö

ʹÓÃAndroid Studio×Ô´øµÄAndroid Profiler

±¼À£Ç°µÄ×î´ódump heapºó×î´óµÄBitmap

Bitmap²ÎÊý

density:280
width:1920
height:1080
mBuffer[]: 8294400¡¡

Size

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Crash ͼƬÎļþ´óС£º Ô¼76.3K ׼ȷ76251

1080PͼƬ´óС£¬RGBA 8888¸ñʽ
ÿ¸öͨµÀÕ¼8bite = 1byte, 4ͨµÀͼÏñµÄ1¸öÏñËØ=4byte
1920*1080*4= 8294400B 8294400/1024/1024 = 7.9101MB
ËùÒÔ£¬1080PµÄͼƬÔÚÄÚ´æÖÐÕ¼Óò»µ½8M.
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×¢Òâ ·¢ÉúOOM֮ǰHeap dump³ö×î´óµÄBitmap¡¡²»ÊDZÀÀ£Ê±µÄ,ÊÇÖ®ºóµÄBitmap

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//        µ÷ÓôúÂë
//        Bitmap bitmap = BitmapUtils.getScaledBitmapFromFile(graphicFile.getAbsolutePath(),
//                1920, 1080);

    public static Bitmap getScaledBitmapFromFile(String filePath, int requiredWidth, int requiredHeight) {
        BitmapFactory.Options options = new BitmapFactory.Options();
        options.inJustDecodeBounds = true;
        BitmapFactory.decodeFile(filePath, options);
        options.inSampleSize = calculateInSampleSize(options, requiredWidth, requiredHeight);
        options.inJustDecodeBounds = false;
        options.inPreferredConfig = Bitmap.Config.ARGB_8888;
        //don't use same inputstream object as in decodestream above. It will not work because
        //decode stream edit input stream. So if you create
        //InputStream is =url.openConnection().getInputStream(); and you use this in  decodeStream
        //above and bellow it will not work!
        Bitmap bm = BitmapFactory.decodeFile(filePath, options);
        return bm;
    }


    /** ¸Ã·½·¨¼´ÊǼÆËãͼƬËõ·Å±ÈÀý
     * options ԭͼµÄ²ÎÊý
     */
    private static int calculateInSampleSize(BitmapFactory.Options options, int reqWidth, int reqHeight) {
        // Raw height and width of image
        final int height = options.outHeight;
        final int width = options.outWidth;
        int inSampleSize = 1;

        if (height > reqHeight || width > reqWidth) {

            final int halfHeight = height / 2;
            final int halfWidth = width / 2;

            // Calculate the largest inSampleSize value that is a power of 2 and keeps both
            // height and width larger than the requested height and width.
            while ((halfHeight / inSampleSize) >= reqHeight
                    && (halfWidth / inSampleSize) >= reqWidth) {
                inSampleSize *= 2;
            }
        }

        return inSampleSize;
    }