Post on 11-May-2015
description
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Image handling in AndroidImage handling in Android
Tyrone Nicholas@tyronentnicholas@fb.com
Tyrone Nicholas@tyronentnicholas@fb.com
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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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’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
tnicholas@fb.com@tyronen