Expansion File Compression

Solar2D Android
#1

Hello,

I’m using the Corona Simulator to build my game for Android. I’ve enabled Expansion Files because of its large size. When I upload my expansion file to Google Play, I get the following warning message:

Warning

APK expansion file might be highly compressible. Compressing with

zip -9

could significantly reduce its size: the first 50.0 MBs were found to be 7.34% compressible.
Ignore this warning if you have optimized for memory/performance. See Using the APK Expansion Zip Library for more information.

So I wanted to check if this was a known issue or not. Making the download files as small as possible would be great.

Thanks,

George

#2

I have the same warning. I just ignore it. No problems with my expansion files in Android store.

#3

We don’t compress them because it creates performance problems.  Since you are including mostly images and audio in these files, they are already highly compressed and re-compressing them doesn’t do much. 

Rob

#4

Rob is right.  We’ve purposely zipped it with zero compression for fast loading.  In my tests, loading an image file is roughly 3x faster from an uncompressed expansion file versus a compressed expansion file.  But if you are concerned about this, then you can always unzip the expansion file Corona Simulator creates for you and then re-zip it with compression.  Just be prepared for longer loading times.

#5

Great, thanks for the response guys!

#6

I have the same warning. I just ignore it. No problems with my expansion files in Android store.

#7

We don’t compress them because it creates performance problems.  Since you are including mostly images and audio in these files, they are already highly compressed and re-compressing them doesn’t do much. 

Rob

#8

Rob is right.  We’ve purposely zipped it with zero compression for fast loading.  In my tests, loading an image file is roughly 3x faster from an uncompressed expansion file versus a compressed expansion file.  But if you are concerned about this, then you can always unzip the expansion file Corona Simulator creates for you and then re-zip it with compression.  Just be prepared for longer loading times.

#9

Great, thanks for the response guys!