Image handling in Android

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Image handling in AndroidImage handling in Android

Tyrone Nicholas@[email protected]

Tyrone Nicholas@[email protected]

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•~1/10 device RAM

•480 x 800 = 1.5 MB

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GCGC

java.lang.OutOfMemoryError

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Android heapsAndroid heaps

Dalvik

•JDK

•Limited

•Slow

•Safe

Other

•Certain system

calls

•Like native

Native

•NDK

•Unlimited

•Fast

•Unsafe

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What to do with images?What to do with images?

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An image pipelineAn image pipeline

WebP

BMP

BMP JPG

JPG

JPG

UI thread Non-UI threads

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Copying heap to heapCopying heap to heap

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Using native heap from JavaUsing native heap from Java

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BitmapsBitmaps

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AshmemAshmem

• create

• pin

• unpin

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Purgeable bitmapsPurgeable bitmaps

DrawDraw DecodeDecode PinPin

Stop drawin

g

Stop drawin

gUnpinUnpin

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Using Purgeable BitmapsUsing Purgeable Bitmaps

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Er, wait a minute…Er, wait a minute…

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Solution #3 – Bitmap PoolingSolution #3 – Bitmap Pooling

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Hang on…Hang on…

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Facebook

’s

solution

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From the Android NDKFrom the Android NDK

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Create a new method…Create a new method…

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…and use it…and use it

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But afterwards…But afterwards…

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Q & A

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