[casual_games] Question about iphone game development

[Tom Hubina]

OK .. it took some digging, but I finally figured it out. It's  
basically what the folks at Apple told Chris - but it's not a fixed  
size. It's based on the size of your executable. Here's the more  
detailed explanation:

The difference between the IPA and the zip you send up to them starts  
off with about 130k for the iTunes artwork and other little files.  
This number will vary depending on how well your 512x512 iTunes  
artwork compresses with png, but in the case I was looking at it was  
about 130k.

All of the resources (sounds, images, etc) have roughly the same  
compression before and after the trip through Apple. The only  
difference I found was with the executable itself. Whatever encryption  
they do to the executable inside the .app as part of their DRM  
drastically changes its ability to be compressed by zip.

For the game I was looking at the uncompressed size (1488k) is the  
same before and after sending to Apple so they didn't add anything to  
the executable. However, the compressed size of the executable went  
from 625k inside the zip up to 933k inside the IPA. I pulled the  
executable out and compressed it with the same zip tool used to  
compress the original sent to Apple and it was still 933k. The "same"  
file couldn't be compressed anywhere near as well as it used to.

So basically, after DRM encryption the compressed size of your  
executable will be about 50% larger than it was, but the uncompressed  
size will be the same. Given that Unity is a baseline 8 meg compressed  
executable (from a previous comment) I would expect Unity games to  
grow by a minimum of 4 megs when you submit them to Apple. That  
happens to be what others are seeing, so the numbers appear to check  
out.

To be clear - this isn't a slam on Unity, it's good stuff - I just  
wanted to solve the damn puzzle of why Unity based games were seeing a  
larger impact by the encryption / DRM than others. However, it does  
mean that the Unity library effectively adds 12 megs to your game, not  
the 8 that was originally stated. This wouldn't be a big deal if it  
wasn't for the 10 meg limit on OTA downloads.

Tom

On Jun 24, 2009, at 2:42 AM, Andres Martinez wrote:


> Please take a look at this picture...  http://www.bakno.com/Billiards/iPhone.png

>

> The System Info from the actual compressed file of our Billiards  

> game:  6MB on disk (6,248,966 bytes). And the same application is  

> 11.6M on the App Store. Almost double the size!!!!!!!!!

>

> I also doubted that a DRM can take that much. But reading the Unity  

> forums I found that this is not the only case.

>

> Regards,

> Andres Martinez

> www.baKno.com

>

>

> On Jun 23, 2009, at 4:14 PM, Tom Park wrote:

>

>> I have to agree that the DRM does add a little to the zip file,  

>> usually about 0.1 or 0.2 MB.

>>

>> Definitely NOT 4MB, not even when comparing unzipped .ipa files.

>>

>>

>> On Tue, Jun 23, 2009 at 11:39 AM, Chris Dillman <chrisd at plaidworld.com 

>> > wrote:

>> It is true Tom

>>

>> The majority of our iPhone apps are sub 10M (some are even 6M  

>> compressed), and none of them is sub 10M on the App Store.

>>

>> When we asked Apple about this inconsistency, they explained that  

>> the extra code is from their own encryption added before  

>> compressing it again (a.k.a DRM).

>>

>>

>> Finder reports..

>>

>> Mouse House Lite 1.1.4

>>

>> Raw = 10.66 MB ... OR 10,442,581 BYTES

>>

>> Zipped = 9 OR 9,401,408 BYTES

>>

>> App store IPA... itunes says its 9.3

>>

>> Finder actually reports 9.3 and 9,705,884 BYTES

>>

>> So I see at least a small increase in a non unity app mostly  

>> consisting of

>> PNG, WAV, MP3 files and Text data.

>>

>>

>>

>>

>>

>>

>> -- 

>> Plaid World Studios http://www.plaidworld.com

>>

>>

>>

>>

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