Qt Android 5.3 Application Size

rschalch · wrote on 22 May 2014, 12:47

So I'm new with Qt and tried to create the most simple app (qtquick) for my device, just to check load time an size.
For my surprise there was a 32 mb app just for a textinput and a slider.
Am I doing something wrong ?
Tks

SGaist · wrote on 22 May 2014, 20:04

Hi,

I would say no, have a look at the dependencies. You probably have several of Qt's libraries along your application

rschalch · wrote on 22 May 2014, 20:31

I went to Build & Run and in the Deployment Configurations under Run Settings / Deploy Configurations the option "Bundle Qt Libraries in APK" is checked but not specified who are they.

In my QML are the imports:
import QtQuick 2.2
import QtQuick.Controls 1.1

I know there's a lot of documentation but sometimes is difficult to get to the right place. Please help me solve this "too many libraries" problem.

SGaist · wrote on 22 May 2014, 21:53

I didn't say too many, for a QtQuick application you have at least QtGui, QtCore, QtQuick

Gianluca · wrote on 23 May 2014, 06:43

There is something strange into your project, because it seems too big 32Mb if you are talking about APK size.
For my android project on which I have qml, qtquick, network, multimedia and svg (and others) dependencies my APK occupy only 12Mb.

But of course, the dimension on the device are bigger when the app is installed. For my app is about 38Mb.

And don't by surprise for that even if your project is very simple ... do you have an idea of how many things Qt provides for you behind a "simple" TextInput and Slider ?

rschalch · wrote on 23 May 2014, 14:37

Well, it discourages me to use Qt for building android apps, even with performance and the pleasure of making Qt applications. Unless we can make a simple app like you said, maximum 10-12 mb

Gianluca · wrote on 23 May 2014, 14:44

If the size it's a problem for you, there is an alternative: use Ministro.
Ministro is an android service that provides Qt libraries.
In this case, your app will be very very small, and when someone install the app from google play automatically he/she will be asked to install also Ministro service.

sonyericsson0819 · wrote on 24 May 2014, 09:58

Yeah,I also think the size is too large.My app was about 7~8 MB ,when I used Qt5.2.1,but now I use Qt5.3.0 to deploy the same application,its size is about 8~9 MB,become larger.And I also find that it has a "white screen" when the application starts or quit,which is never appear in Qt5.2.1 application.

Gianluca · wrote on 24 May 2014, 10:46

Just to continue the discussion about the size of an app: what's the problem if the app is something like 30Mb ? I really don't understand what bother you.
I've never read a statistic telling that the users choose app depending on the dimension they occupy on their mobile phone. Typically the users doesn't care about the dimension of an app. And almost all mobile phone of 3-4 years ago have enough space to install hundreds of apps.

Or I'm underestimating the size problem ??

rschalch · wrote on 24 May 2014, 14:09

More size, more memory, less chance of the app run fine when other software is on. I think we cannot undersetimate the size at least for now

Gianluca · wrote on 24 May 2014, 14:26

That's not true. (I think). Because the size is due to the Qt library that cannot be splitted at a very fine grained level... but that doesn't means that your app need to have all library symbols on memory (RAM) at the same time to run fine.

If you did a very simple app that use only the 10% of exported symbols of the Qt libraries, that in memory (RAM) there will be only the 10% of the dimension totally occupied on the disk.

So, If we want to discuss the problem of the size, we should really check how much is the effective needed RAM in order to run the app without affecting the performances.

For Android I don't know how to check it, but for iOS Xcode display the RAM memory needed by the app at runtime.
And for example, my app that on iOS is ~40Mb of .ipa, when it runs it occupies only ~5Mb of RAM.

rschalch · wrote on 24 May 2014, 14:53

Yeah, perhaps who made the tests of the latest Qt on an average android device can tell us how the app reacts in a situation when other apps are open. If the performance still goes well I think we can forgive the size app.

Gianluca · wrote on 25 May 2014, 08:37

My android devices as testbed are an LG L7 bought 4 years ago, and a 7'' inch tablet without brand imported from china one years ago and payed about 50€

I didn't do performances checks because I don't know how to profile an android app regarding CPU and RAM usage.

I'll came back after I did more tests and profiling.

Gianluca · wrote on 30 May 2014, 07:35

Some news about memory usage of the Qt app on Android.
Following this guide:
https://developer.android.com/tools/debugging/debugging-memory.html
I checked some usage of my application.
Consider that is an application using Qt Quick (Layout, Controls), Qt Network, Qt Multimedia, Qt Svg and all modules on which these depends on.

The memory on disk of this APK is about 40Mb.

When the app runs, the maximum space seen on the heap is 2966K/3468K (active_used / totally_for_the_app )
And the private dirty memory on RAM (the very important for keeping the phone reactive) goes up and down around the 6800K / 2100K (Native / Dalvik ).

So, this definitely prove my assumption that the RAM needed is very different from the space needed on disk.

rschalch · wrote on 30 May 2014, 13:34

Yes, its reasonable. Thanks for the tests !

rjklindsay · wrote on 19 Jun 2014, 02:51

I'm sorry, but such HUGE executables are completely unacceptable.
Keep in mind the entire Win95 operating system required only 55Mb of hard-drive space, which was already big and bloated, compared to RiscOS (4Mb). I see some apps in the Google Play app store are only 24kb or smaller. Now Gianluca is trying to convince us that a Hello-world app of more than x1000 that size is acceptable? I think not! I certaintly won't be using Qt for my next Android project, unless they can SIGNIFICANTLY reduce the APK size.

rschalch · wrote on 19 Jun 2014, 12:35

I would say that for small apps we can go with pure Java, but man, developing in QtQuick is so much fun ... the main libraries may encapsulate all the things that we commonly dont use. but for a richer app, maybe the 32-33 mb can be acceptable

rjklindsay · wrote on 20 Jun 2014, 02:22

I'm no fan of Java, which is why I'm looking for alternatives.
I must admit, I really like QtQuick, but the APK size makes it a non-starter. On my Samsung SII, a simple QtQuick app takes between 5 and 20 seconds to start, whereas a ADT+NDK app starts up in under a second. Also, Google Play has an APK size limit of 50MB, and a 'richer' app could easily exceed that limit. To make things worse, many devices have a 30MB download cache limit, so even if you get your 32-33 MB app uploaded to Google play, many devices would not be able to download it. Btw. FireMonkey on Delphi/C++ Builder is another excelent RAD tool for developing Android apps, but unfortunately it also suffers from over-size APK's. So, for now I see no choice but to stick to Eclipse ADT+NDK.

rschalch · wrote on 20 Jun 2014, 03:20

Well, we still have the option of deploy the "small" app and have users to download Ministro from Google Play. None of this would be an ideal solution but answer me honestly: Whats better and more fun than QtQuick for development ? I think we can also believe in its future :)

hmbright · wrote on 9 Feb 2015, 06:08

i can kind of see both sides. i understand how this may be a problem for some. for example in the US on some phone providers on some contracts, 30 mb of mobile-network data can incur a significant cost. and it can be quite slow.

on the other hand, Podcasting has become extremely popular in the US, and an ordinary podcast mp3 can frequently be 30MB to 50MB. Videos of course are much much more. i have a feeling most people download these podcasts over wifi to their phone and listen later. this is relatively speedy and works well for many people.